PLANT BREEDING NEWS
EDITION
160
10 October 2005
An Electronic Newsletter of Applied Plant
Breeding
Sponsored by FAO and Cornell University
Clair H. Hershey,
Editor
A NOTE ABOUT FORMAT: Many subscribers have written that they
have been unable to use the internal document hyperlinks (to jump to specific
articles) in the past few issues of the newsletter. This appears to be an
unanticipated result of an update of Cornell’s e-mail system, and I will
continue to work at finding a solution.
Archived issues available at:
http://www.fao.org/WAICENT/FAOINFO/AGRICULT/AGP/AGPC/doc/services/pbn.html
(NOTE: cut and paste link if it does not work
directly)
CONTENTS
1. NEWS, ANNOUNCEMENTS AND RESEARCH
NOTES
1.01 Venezuela joins the global efforts for breeding water-saving and
drought tolerant rice
1.02 Southern African network for biosciences
launched
1.03 Formation of Barley Breeding Australia to double the
size of Australia's barley industry
1.04 Cornell University
tapped for regional Sun Grant hub to use $8 million in U.S. funds to spearhead
next green revolution
1.05 Scottish Crop Research Institute and
Dundee University receive E.U. grant to investigate natural
resistance of several important crop plants
1.06 CSIRO cotton
breeders win innovation award
1.07 ICRISAT, partners
identify new research priorities
1.08 Biodiversity loss
poses grave threat to human health
1.09 China holds top
aquatic vegetable gene bank
1.10 A single gene
controls a key difference between maize and its wild ancestors
1.11 Medicinal plants - time to harness the potential of neglected genetic
resources?
1.12 Corn ancestor’s pollen studied
1.13 Genetic improvement for tolerance to phosphorus deficiency in rice
1.14 Thai breeders develop GM breeds of jasmine rice tolerant to flooding,
bacterial leaf blight and leaf blast
1.15 UCR biochemist goes
to Washington with high-protein corn
1.16 Australian breeders develop new
phytophthora root rot resistant variety by crossing chickpea
with a wild cousin
1.17 Super resistance to tackle biggest wheat
disease
1.18 Higher rice yields with no extra water
1.19 Why does salinity
pose such a difficult problem for plant breeders?
1.20 ’Defender’ is first
commercial potato in the United States to resist late blight
1.21 New kidney bean
germplasm line resists common bacterial blight disease
1.22 Hybrid grass may prove to be valuable fuel source
1.23 New high sugar
grass released
1.24 Paper recounts research on salinity-tolerant
plants
1.25 Fungus confers salt resistance to plants
1.26 Washington State
University researchers find a key to plant growth
1.27 Plant genes 'offer
safer option for GM crop research'
1.28 QTL detection and
application to plant breeding
1.29 CSIRO's gene
silencing granted US patent
1.30 Salt-tolerance
gene could lead to higher rice yields
1.31 How many genes
influence plant growth?
1.32 Haploid cell lines in sugar beet breeding
1.33 New strain of wheat rust appears in Africa
1.34 Role of plant gene
in heat tolerance studied
1.35 Findings on Mexico
maize released
1.36 Mexican maize transgenes issue examined
1.37 Molecular marker
development for carrot sugar types.
1.38 FAO-BiotechNews:
excerpts from Update 9-2005
1.39 FAO-BiotechNews:
excerpts from Update 10-2005
2. PUBLICATIONS
2.01 Free genetics statistics software - GenStat Discovery Edition
(DE)
2.02 Marker assisted selective breeding
2.03 Setting breeding
objectives and developing seed systems with farmers --- A handbook for
practical use in participatory plant breeding projects
3. WEB RESOURCES
3.01 "Gramene" database
facilitates global agricultural research
3.02 CAB Abstracts
archive available for searching on CAB Direct
3.03 CSREES (USDA) projection about ag
employment opportunities.
4 GRANTS AVAILABLE
(None posted)
5 POSITION ANNOUNCEMENTS
(None posted)
6 MEETINGS, COURSES AND
WORKSHOPS
7 EDITOR'S
NOTES
=========================
1. NEWS, ANNOUNCEMENTS AND
RESEARCH NOTES
1.01 Venezuela joins the global efforts for breeding water-saving
and drought tolerant rice
Thaura Ghneim (1), Alejandro Pieters(1),
Iris Pérez Almeida(2), Gelis Torrealba(3), César Martinez(4), Mathias
Lorieux(4), Joe Tohme(4).
(1)Instituto Venezolano de Investigaciones
Científicas. Apdo. 21827. Caracas, Venezuela. tghneim@ivic.ve, apieters@ivic.ve
(2)Instituto Nacional
de Investigaciones Agrícolas. CENIAP. Apdo. 4653. Maracay, Edo. Aragua 2101A,
Venezuela. iperez@inia.gov.ve
(3)Instituto
Nacional de Investigaciones Agrícolas. Apdo N°14. Zona Postal 2312 Edo.
Guárico, Venezuela. gtorrealba@inia.gov.ve
(4)Centro
Internacional de Agricultura Tropical. A.A 6713, Cali, Colombia. c.p.martinez@cgiar.org; j.tohme@cgiar.org, m.lorieux@cgiar.org
Latin America
and Caribbean (LAC) countries do not escape the world-wide concerns about
drought and its effects on rice cultivation. In this region, rice is
cultivated mainly under irrigated conditions. Although, per capita
water availability in LAC is the highest among continents this advantage is
decreasing (FAO, 1994). In the recent past, rice cultivation in several LAC
countries had water shortage problems. In Venezuela, for example, inadequate
water availability in the main producing areas, resulting from a three year
drought, affected paddy production in the last two years (FAO 2004). Thus it
appears that- similarly to other regions of the globe- the stability of rice
production in LAC countries will depend on the development and adoption of
strategies that allow using water more efficiently in irrigation
schemes.
Recently, Venezuela joined the global efforts for breeding
water saving and drought tolerant rice. Last January, our research team
constituted by plant physiologists, plant breeders, and molecular biologists
from the Instituto Venezolano de Investigaciones Científicas (Venezuelan
Institute for Scientific Research, IVIC, www.ivic.ve), the Instituto Nacional de
Investigaciones Agrícolas (National Institute for Agricultural Research, INIA, www.inia.gov.ve, and the International
Center for Tropical Agriculture (CIAT, www.ciat.org) initiated a research project
which long-term goal is to identify and breed rice cultivars with a higher
water use efficiency and able to tolerate drought.
Our research
strategy consists in three phases: (i) characterize the drought tolerance of
various rice cultivars, (ii) identify the most important traits associated to
drought tolerance in these cultivars, and (iii) develop genetic maps and
identify quantitative trait loci (QTL) associated to drought tolerance. For
this, we are screening accessions from Venezuelan germplasm, constituted
mainly by lowland varieties, in order to identify new donors exhibiting stable
performance under water stress, with good yield potential and having different
drought tolerance mechanisms that can bring potential new genes/QTLs into the
breeding pool. These accessions represent traditional and novel Oryza
sativa materials from Venezuelan germplasm; their responses to
water-shortage have not been characterized previously.
In addition to
local germplasm, we are evaluating Oryza glaberrima (IRGC accession
103544) and Oryza sativa cv. Caiapo, in order to establish their
potential as donors/recipients in drought-breeding programs. The
characterization of these materials will also be useful for determining the
suitability of a Caiapo x O. glaberrima mapping population-developed by
CIAT- for the identification of drought-related QTLs. Oryza
glaberrima is the native cultivated rice in West Africa. Some accessions
of this species, as well as some lines derived from its crossings with O.
sativa (NERICA lines), exhibit enhanced tolerance to several abiotic
stresses including drought (JIRCAS 2003; Fujii et al., 2004). Caiapo is a
tropical japonica commercial variety developed by the Brazilian rice program
for upland conditions (EMBRAPA 1997)), and has been reported as moderately
tolerant to drought (Pinheiro 2003). The Caiapo x O. glaberrima
population consists of 93 chromosome segment substitution lines (CSSLs) which
represent 95% introgression of O. glaberrima (IRGC accession 103544)
genome into Caiapo genetic background. A genetic map for this population is
already available (Lorieux, pers. comm.). CSSL will be evaluated for yield and
selected drought-related traits exhibiting significant contrast between
parents.
The genetic materials included in the study might
exhibit different mechanisms important in determining tolerance to water
stress (i.e. osmotic adjustment, stomata adjustment or deep root systems),
thus potentially we will have the opportunity to identify and map different
traits.
Developing drought-tolerant or water-saving cultivars -through
molecular breeding- is considered one of the most effective strategies for
enhancing water use efficiency in rice cultivation. Several lines of evidence
indicate good possibilities for rice. Rice varieties that are better able to
tolerate drought are known, and several putative traits that confer drought
tolerance to rice have been identified. Furthermore, genotypic variation for
several of these traits has been reported. However, drought tolerance is a
complex trait, controlled by the interaction of many genes, as it involves
several physiological, biochemical, phenological, and morphological
mechanisms. This polygenic nature of drought tolerance implies that several
genetic regions must be manipulated simultaneously to have a significant
impact on crop performance under water-limited conditions. QTL mapping offers
an opportunity to identify these regions or loci conferring tolerance to
drought.
However, the breeding of new materials with enhanced drought
tolerance could take a long time. Our step-by-step approach offers the
opportunity to identify in the short-term local cultivars that can perform
better under reduced irrigation. The cultivation of these materials can be
promoted to reduce- in the short-term- water use. This approach also represent
an advantage for breeding new materials, as these varieties already show
adaptation to local conditions, yield and grain quality that are acceptable to
producers.
In Venezuela, the molecular characterization of rice
cultivars has been very limited. Genotyping of the cultivars included in this
study-which represent 8 of the varieties most cultivated in the country- is of
great importance not only for the work being carried out in our project, but
also because it will offer molecular information to other areas of research,
to plant breeders and also to the seed industry.
The collaboration of
CIAT in the project is helping to strengthen personnel capacities in the
country in the area of biotechnology, through training of students and
researchers. At the same time, IVIC and INIA are exchanging expertise in crop
physiology and biochemistry, and plant breeding. We are looking forward
to establish collaboration links with other research institutes, both national
and international, in this area of research. In the next months, we are
launching a web-site (www.ivic.ve/retoarroz) containing
information about the project, training opportunities, publications, etc.
Financing support for this project is through a 2004-2006 grant from
the Venezuelan Fondo Nacional de Ciencia y Tecnología FONACIT (National
Science and Technology Fund), dependent of Ministerio de Ciencia y Tecnología
MCT (Science and Technology Ministry).
Contributed by Thaura
Ghneim
Instituto Venezolano de Investigaciones Científicas,
Caracas
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1.02
Southern African network for biosciences
launched
Talent Ngandwe
[LUSAKA] Efforts to build capacity for
biological research in southern Africa were given a boost this month with the
creation of the Southern African Network for Biosciences (SANBio).
The
New Partnership for Africa's Development (NEPAD) and South Africa's Council
for Scientific and Industrial Research (CSIR) formally launched the network in
Tshwane (formerly Pretoria) on 5 August.
SANBio will bring together
researchers and institutions from 12 countries across the region and encourage
them to pool their knowledge and resources. It will focus on research relating
to agriculture, human and animal health, the environment and
industry.
The network was created as part of NEPAD's African
Biosciences Initiative, which aims to build regional networks of 'centres of
research excellence'.
The network's hub for southern Africa will be in
South Africa. Other hubs being developed are Egypt (for north Africa), Kenya
(east and central Africa) and Senegal (west Africa).
Members of SANBio
will be drawn from Angola, Botswana, Lesotho, Malawi, Mauritius, Mozambique,
Namibia, the Seychelles, South Africa, Swaziland, Zambia and Zimbabwe. Namibia
will chair the network's steering committee for the next year.
Source:
SciDev.Net
22 August 2005
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1.03 Formation of Barley Breeding
Australia to double the size of Australia's barley
industry
Formation of Barley Breeding Australia (BBA) by GRDC, the Western Australia Department of
Agriculture, Sout Australia Research & Development Institute, New South
Wales and Victorian Departments of Primary Industries and Fisheries and the
University of Adelaide will double the size of Australia's 6.6 million tonne
barley industry to satisfy demand increases by 2020.
GRDC has
outlined its plan for consolidation of grains R&D that is a key to
delivering the anticipated massive growth.
Terry Enright, GRDC
Chairman, said aligning plant breeding programs across Australia would deliver
better varieties faster and was a way that we could position the industry
better to meet this challenge and maximize returns.
"We face a
constantly changing grains industry and we need to move quickly, positively
and differently to keep ahead of our competition," Mr Enright
said.
Source: SeedQuest.com
21 September 2005
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1.04 Cornell University tapped for regional Sun Grant hub to use
$8 million in U.S. funds to spearhead next green revolution
Ithaca,
New York
In a time of skyrocketing gasoline prices and concerns over
global warming, Cornell University is
helping to spearhead the next green revolution by using plants to produce
energy, industrial chemicals and green materials.
Awarded more than
$8.2 million in federal funding over four years through the recent signing of
the federal Transportation Bill, Cornell has been tapped by the federal
government as one of five Sun Grant Centers of Excellence -- regional hubs
that will take the lead in researching the use of plant biomass in energy and
chemical production; for education and outreach activities; and for soliciting
and funding proposals that focus on using renewable agricultural resources to
produce heat, electricity, biofuels, natural products, such as biopesticides
and bioherbicides, and industrial chemicals.
"With our global
community entering a less certain oil future, over the next 10 to 25 years,
there will be a major transition to agricultural-based bio-industries," said
Larry Walker, professor of biological and environmental engineering at Cornell
and director of the institute.
Cornell, the land-grant university of
New York state, is the lead university for the Northeast Sun Grant Institute
of Excellence, which serves 14 states and the District of Columbia, from Maine
to Maryland to Michigan. That makes Cornell one of only two universities in
the nation, along with Oregon State University, now designated by the federal
government in all of the four categories of land, sea, space and sun grant
institutions.
"Genomics, nanobiotechnology and breakthroughs in
molecular biology, genetics and biological engineering have opened up a broad
spectrum of opportunities and challenges for manipulating microbial and plant
systems to produce novel organic compounds and to meet part of the U.S. and
world energy needs," said Walker. "Opportunities abound for integrating these
advances in engineering and science into regional, national and global efforts
to develop sustainable industries and communities."
Involving at least
two dozen Cornell faculty members, the institute was established in 2004 at
Cornell. But it was not until the passing of the Transportation Bill in August
that the institute was given the funding needed to solicit and award
competitive grants to regional land-grant universities to work in partnership
with industry, governmental agencies, communities, private entrepreneurs and
others stakeholders for bringing the bio-economy to the region.
The
Northeast Sun Grant Initiative will focus on biopower -- energy produced from
renewable biomass for heat and electricity; biofuels -- liquid and gaseous
transportation fuels, such as bioethanol and biodiesel, made from biomass
resources; and bioproducts -- chemicals and materials that are traditionally
made from petroleum-based resources but will be made from biomass. In each of
these strategic areas, initiatives will involve feedstock development,
conversion processes, systems integration and biomass public policy issues.
Currently, less than 10 percent of chemicals and commodities and less
than 5 percent of U.S. energy supplies are derived from agriculturally based
resources, Walker pointed out.
"Our vision is to rethink how many of
the material needs of society can be met by using renewable agriculturally
based raw materials," Walker said, noting that Cornell is an ideal location
for the Northeast Sun Grant Institute because "it is one of very few
institutions in the world that can bring together so many physical and life
scientists, engineers and social scientists with the talent and interest in
sustainable development, or that has access to so many bright young minds."
The Sun Grant centers not only will promote the development of
bio-based energy technologies but also environmental sustainability as well as
boost the economic vitality and diversity of rural communities, said Walker.
He praised New York's congressional representatives -- Sherwood Boehlert,
Maurice Hinchey and Jerome Nadler as well as U.S. Senators Hillary Clinton and
Charles Schumer -- for their support of funding for the consortium. Gov.
George Pataki's Washington office was also helpful in the political process,
he said.
Michael Hoffman, director of the Cornell University
Agricultural Experiment Station, said: "Funding of the Sun Grant is truly
great news for Cornell, the Northeast and the nation. The Sun Grant is well
positioned to help us diversify our energy supply portfolio, more important
now then ever before, and generate a multitude of new natural products and
industrial chemicals. We see many economic and environmental benefits for New
York state farms and communities thanks to the Sun Grant."
The
Northeast Sun Grant Institute at Cornell serves a region that includes the
states of Connecticut, Delaware, Massachusetts, Maryland, Maine, Michigan, New
Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont,
Washington, D.C., and West Virginia. The other regional Sun Grant Centers of
Excellence are at Oregon State University-Corvallis; University of
Tennessee-Knoxville; Oklahoma State University, Stillwater; and South Dakota
State University-Brookings.
Campus bio-energy and bioproducts
projects:
With more than 400 life scientists at Cornell, a multitude
of bio-energy and bioproducts projects are already under way on campus. They
include:
-pretreating switch grass and alfafa to improve their enzyme
conversion to fermentable sugars;
-engineering enzymes that are more
effective in converting cellulose derived from herbaceous crops and grasses
into fermentable sugars to be converted into industrial chemicals;
-developing molecular ecology techniques to prospect for novel industrial
enzymes and microorganisms from extreme environments;
-engineering plants
to effectively produce important industrial enzymes and industrial compounds;
-applying nanofabrication and single-molecule confinement methods to
investigate molecular mechanisms of important industrial enzymes;
-enhancing ethanol tolerance and production in yeast through understanding
and manipulating membrane restructuring;
-converting dairy manure-derived
biogas from anaerobic digestion to produce electricity, hydrogen and heat on
dairy farms;
-utilizing used vegetable oil from restaurants to replace
diesel fuel for vehicles;
-investigating the technical and economic
constraints of using digester and landfill gases to operate fuel cells;
-developing environmentally friendly bioherbicides to control
plant-pathogenic bacteria and fungi;
-screening molecules for novel
compounds in diverse organisms for their genetic capacity to synthesize some
important families of natural products, such as antibiotics and insecticides;
-developing microbial biopesticides through combined approaches of genetic
engineering, fermentation optimization and process engineering; and
-testing the burning of grass pellets as a biofuel.
Many Cornell
graduate students are involved in carrying out these research activities
through the U.S. Department of Agriculture Multidisciplinary Graduate and
Education Training Program for bio-based industries.
By Susan S. Lang
Source:
SeedQuest.com
21 September 2005
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1.05 Scottish Crop Research Institute and Dundee
University receive E.U. grant to investigate natural
resistance of several important crop plants
Invergowrie,
Scotland
Scientists from the Scottish Crop
Research Institute (SCRI) and Dundee
University have been jointly awarded £1.25M from the EU to investigate the
natural resistance of several important crop plants to potentially devastating
plant diseases.
The team, led by Drs. Robbie Waugh, Glenn Bryan,
Paul Birch, David Marshall (SCRI) and Andy Flavell (Dundee), will use state of
the art molecular technologies to identify the specific variants of genes that
contribute towards resistance to diseases such as late blight on potatoes and
scald on barley that annually cause hundreds of millions of pounds of damage
worldwide. They then aim to translate their discoveries into new
breeding lines of potato, wheat and barley by developing both germplasm and
diagnostic tools that can be used by plant breeders to improve resistance in
the commercial crops.
At the moment, many common crop varieties
require the application of large amounts of pesticides and fungicides
throughout the growing season to protect the crop from disease. While
this practice has been immensely successful in improving crop yield and
quality, serious concerns have been raised about the impact it has on both the
environment and the consumer.
The most attractive and
sustainable solution to this problem is to develop varieties containing
natural resistance as they can then protect themselves against attack. This is particularly important in the organic sector where the application of
many agrochemicals is prohibited.
By identifying the genes and
understanding the mechanisms involved in the infection process and which
result in a plant being either resistant or susceptible, the research will
identify new sources of natural disease resistance and develop diagnostics
that will help plant breeders mobilise this resistance into new varieties for
the farmer.
SCRI increases knowledge in plant and
environmental sciences. The research is focussed on plants to improve the
understanding of processes that regulate their growth and response to pests,
pathogens and the environment. This includes understanding genetics to breed
crops with improved quality and nutritional value as fast as possible. By
understanding the plant’s response to pests and diseases and how they react to
the soil, air and water around them, environmentally friendly methods of
protecting crops from the ravages of pests, diseases and weeds can be
designed.
SCRI is grant-aided by the Scottish Executive Environment and
Rural Affairs Department (SEERAD) and has charitable status. It is one of five
Scottish Agricultural and Biological Research Institutes (SABRIs) which,
together with those of the Biotechnology and Biological Sciences Research
Council, form the agricultural and food research service of the
UK
Source: SeedQuest.com
28 September 2005
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1.06 CSIRO cotton breeders win innovation award
CSIRO Plant Industry's cotton breeding team
on 6 September, won Innovate Australia's Australian Government Prize for Rural
Innovation from hundreds of rural innovation contenders Australia-wide.
Presented at Parliament House in Canberra by the Deputy Prime
Minister, the Hon. Mark Vaile, the award for excellence in rural research and
development was accepted by Dr Jeremy Burdon, Chief of CSIRO Plant Industry.
“Our cotton breeding team, currently led by Dr Greg Constable in
Narrabri, have been at the forefront of their area of research for over twenty
years and it is wonderful to see them acknowledged,” says Dr Burdon.
“Every year they produce new regionally adapted cotton varieties with
higher yields, better quality fibre and improved pest and disease resistance – last season 14 new varieties were released.”
The team also led the
introduction of GM insect resistant cotton, both Ingard® and Bollgard® II,
into Australia with the latter now reducing pesticide use by over 80 per
cent.
The Rewards from Innovation night celebrated 16 short listed
innovations which included not only CSIRO Plant Industry's cotton breeding
team, but also the cotton industry's Best Management Practice
program.
Each innovation contending the award provided benefits to the
Australian community, the economy, human health and lifestyle, international
standing and the sustainability of rural industries.
“Support and
partnership with the cotton industry including growers, the Cotton Research
and Development Corporation, the Australian Cotton Cooperative Research Centre
and organisations including Cotton Seed Distributors have made our cotton
breeding work possible,” Dr Burdon says.
“It is estimated that every
dollar invested into our cotton breeding research returns $86 to the
Australian cotton industry.”
A review of the CSIRO's cotton breeding
and biotechnology program by three international experts in 2004 also
confirmed it as one of the most successful of its type in the
world.
Source: SeedQuest.com
9 September 2005
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1.07
ICRISAT, partners identify new research
priorities
The International Crops Research Institute for the
Semi-Arid Tropics (ICRISAT) recently
organized a consultation meeting with the partners of the Hybrid Parents
Research Consortia to identify new research priorities. The Consortia plans to
strengthen linkages with the industry and markets, and attract entrepreneurs
to produce value-added products from sorghum and pearl millet.
Three
consortia are each devoted to research on sorghum, pearl millet, and
pigeonpea .
The thrust areas for renewed research and partnership identified at the
consultation meeting are (1) improved grain yields; resistance to shoot fly,
grain mold and aphids; diversify hybrids parents for post-rainy season
adaptation; and strengthen the development of sweet stalk sorghum for ethanol
production; 2) develop pearl millet hybrids for less endowed regions such as
western Rajasthan; continue the development of hybrids resistant to downy
mildew; and develop hybrid parents and hybrids for fodder use; 3) develop
pigeonpea hybrids with improved seed color and cooking quality; resistance to
pod borer, Fusarium wilt and sterility mosaic virus; and reduce the cost of
hybrid seed production; and 4) find more alternate uses for sorghum and pearl
millet in their respective industries.
For more information, contact S
Gopikrishna Warrier, Media Officer, at w.gopikrishna@cgiar.org.
Visit ICRISAT at http://www.icrisat.org.
From
CropBiotech Update 9 September 2005:
Contributed by Margaret
Smith
Dept. of Plant Breeding & Genetics
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1.08
Biodiversity loss 'poses grave threat to human
health'
Ehsan Masood
[GALWAY] The continued loss of biological
diversity threatens human health as well as the survival of wild species,
delegates at an international conference heard yesterday (23 August).
If species continue to decline in number at the present rate,
pharmaceutical companies will find it harder to develop new drugs and
agriculture will lose an irreplaceable source of potential new crops.
This warning came from Eric Chivian, director of the Center for Health
and the Global Environment at Harvard Medical School, United States.
He was speaking at the COHAB 2005 conference of scientists and
government officials, who were meeting in Galway, Ireland, to discuss how the
loss of biodiversity could affect people's health.
"We are incredibly
lucky to be alive right now … because we have been tampering with the Earth's
life support systems in ways we do not understand," said Chivian. "Do not
underestimate me when I say that we are in deep, deep
trouble."
Hamdallah Zedan, executive secretary of the UN Convention on
Biological Diversity (CBD) secretariat, echoed this message. He said that with
species becoming extinct at up to 1,000-times the natural rate, humankind is
cutting off a lifeline to its future.
About 80 per cent of people in
developing countries rely on traditional plant-based medicines for basic
healthcare, and three-quarters of the world's top-selling prescription drugs
include ingredients derived from plant extracts, he noted.
Zedan
announced that the CBD secretariat has teamed up with the International Plant
Genetic Resources Institute (IPGRI) in Italy to raise awareness of the
importance of biodiversity among agricultural researchers and nutritionists.
IPGRI's director-general Emile Frison told SciDev.Net that the
partnership will include a major research initiative exploring links between
biodiversity and nutrition.
"We don't have much hard data on
developing countries. There are big gaps in our knowledge," he said. "For
example, we need to know the precise benefits to people in the developing
world of what is called dietary diversity."
Studies in Europe and the
United States, he said, show that people who eat a wide range of foods live
longer and have a lower risk of heart disease, diabetes and obesity.
The conference was sponsored by corporations, conservation groups and
the biodiversity divisions of UN agencies. They include the World Conservation
Union, Glaxo SmithKline, the UN Global Environment Facility, the UN
Development Programme and the World Health Organization.
One of their
collective aims is to influence a meeting of world leaders that will take
place next month in New York City, United States. The meeting will track
progress and commit new funds towards meeting the Millennium Development Goals
(MDGs), a set of eight targets intended to halve world poverty by 2015.
One goal is to ensure environmental sustainability, but slowing down
the rate of biodiversity loss is not mentioned explicitly which has
upset many conservationists.
Many of the conference delegates
reiterated concerns that some of the measures being suggested to meet MDG
poverty targets (such as building more roads and expanding agriculture) could
accelerate biodiversity loss (see Protecting
biodiversity 'may clash with pursuit of MDGs').
"Environmental sustainability cannot happen in isolation to other
sectors of society," Zedan said. "We need a much more holistic
approach."
Source: SciDev.Net
24 August 2005
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1.09 China holds top aquatic vegetable gene bank
Jia
Hepeng
[BEIJING] China is home to the world's largest gene bank for aquatic
vegetables, a seminar heard last week.
The repository, which holds
more than 1,700 wild and cultivated specimens from 13 kinds of aquatic
vegetables, is based in the city of Wuhan and run by the Wuhan Institute of
Vegetable Science.
Liu Yuping, a scientist at the Wuhan Vegetable
Research Institute says that the 13 vegetables which include lotus,
water bamboo, taro, water celery, water chestnut and watercress are the
most frequently planted aquatic vegetables in the world. Eleven of them come
from China.
Aquatic vegetables are favourite foods in southern parts of
China. In Wuhan, where more of the vegetables are produced than anywhere else
in the country, 500,000 hectares of them are planted each year, yielding
500,000 tons of produce worth 1 billion yuan (US$123.46 million).
Liu
says aquatic vegetables are "environmentally friendly": they suffer from few
diseases and pests and can be grown without chemical fertilizers.
He
says the institute is seeking to embark on research collaborations to
determine what genes lie behind some of these attractive traits, such as
resistance to pests. The information could be used to improve other crops.
He adds that they would also like to map the genetic sequences of some
of the species, but that this will be more difficult because of the large sums
of money required.
The Wuhan Institute of Vegetable Science has been
developing the gene bank for 15 years.
Most of the vegetables are
conserved as plants, replanted annually in open fields. Reproducing them
asexually allows the researchers to ensure the genes of the different plants
don't mix, preserving their genetic identity.
Source: SciDev.Net
19
August 2005
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1.10 A single gene controls a key difference between maize and its
wild ancestors
Madison, Wisconsin
One of the greatest
agricultural and evolutionary puzzles is the origin of maize - and part of the
answer may lie in a plot of corn on the western edge of Madison, where a
hybrid crop gives new life to ancient genetic material.
While many
biologists argue that teosinte, a wild Mexican grass, is the progenitor of
maize, others believe that the differences between teosinte and maize are too
complex to have arisen through natural mutation or human selection. One of the
most significant inconsistencies between the two plants is that teosinte
kernels are locked in a hardened casing and have to be cracked like walnuts,
while maize kernels are exposed on the surface of the ear.
However, a
team led by a University of
Wisconsin-Madison geneticist has demonstrated that a single gene, called
tga1, controls kernel casing. And beyond implications for the study of maize
evolution, the results are evidence that modest alterations in single genes
can cause dramatic changes in the way traits are expressed, the team wrote in
the August issue of the journal Nature.
"What really interests me is
how traits evolve," says John Doebley, the professor of genetics who led the
study. "How did changes in genes cause the diversity of life to arise on
earth? The corn and teosinte model is an excellent system to investigate this
question."
While Doebley has laboratory facilities on campus, he is
equally at home in the field plots at the West Madison Agricultural Research
Station where he raises second-generation hybrids of teosinte and maize. He
studies the inheritance of different traits in the hybrids and uses genetic
tools to identify the genes involved, applying highly advanced technology to
an ancient species.
The history of corn is closely intertwined with
the history of humans in the New World, says Doebley. "In the Americas, corn -
which was first domesticated in southern Mexico - fueled the societies and the
cultures that developed. Without corn, the societies of the new world would
have been completely different."
However, the genetic changes that
occurred during the domestication of corn have been a controversial issue in
the field of evolutionary biology, Doebley says. "Some argue that evolution
works like building up a sandstone cliff with lots of tiny grains deposited
over a very long time. Others believe that there may be big boulders set into
that cliff - or that evolutionary changes may result from single genes with
very big effects."
In fact, Doebley says that his team's findings "fit
exactly with the idea that a single gene change, or a small number of changes,
could be sufficient to make teosinte a useful food crop, and in a relatively
short amount of time." He adds that it is likely that a change in just one
amino acid within the gene was enough to cause the key event, and ultimately
influence human society in the new world.
The process of maize
evolution might have begun with humans growing teosinte as a food source -
although an inefficient one, says Doebley. "And then in the fields popped up a
new mutation that changed the tga1 gene and reduced the kernel casings," he
says. "Humans then would have applied artificial selection, and soon almost
every plant they grew would have had the exposed kernels."
Although the
results published in Nature shed light on one great mystery, there is much
still to learn. Doebley and colleagues at six institutions are almost halfway
through a five-year project to study the molecular and functional diversity of
the maize genome. At $10 million, the National Science Foundation grant that
supports the project is one of the largest awards ever given for plant
research. Doebley is trying to identify which genes ancient farmers selected
for their crops. In a recent paper published in the journal Science, the team
presented analysis indicating that 2 to 4 percent of the genes in the maize
genome experienced artificial selection.
Doebley's team for the
Nature paper included Huai Wang, a current postdoctoral student; Qiong Zhao, a
current graduate student; Yves Vigouroux, a former postdoctoral student;
Kirsten Bomblies and Lewis Lukens, former graduate students; Tina
Nussbaum-Wagler, a research specialist; and Bailin Li and Mariana Faller,
researchers at the DuPont corporation.
The work is funded by the
National Institutes of Health, NSF, the United States Department of
Agriculture and the state of Wisconsin.
Source: SeedQuest.com
31
August 2005
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1.11
Medicinal plants - time to harness the potential of neglected genetic
resources?
The development of synthetic drugs and
antibiotics in the 20th century has revolutionised the treatment of
many human and animal diseases. However, over 90% of the developing worlds
population continues to rely heavily on herbal medicines to meet their
healthcare needs. Elsewhere, particularly in Europe and North America, the
popularity of herbal medicines is increasing. Even within modern medicine,
plants play a crucial role as a source of leads and raw material for some of
the most important drugs available today. But are we really exploiting their
full potential?
This subject is the focus of the August issue of the
journal Plant Genetic Resources: Characterization and Utilization,
which is devoted to discussing the cultivation, processing, and in
vitro propagation of medicinal plants.
If you would like more
information, a copy of the press release can be found at: http://www.cabi-publishing.org/pdf/news/118pressrelease2005.pdf
Contributed
by Halina Dawson
Editor, Plant Breeding
Abstracts
h.dawson@cabi.org
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Contents)
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1.12 Corn ancestor’s pollen
studied
Today's corn was developed from a domesticated version of
teosinte, a wild grass. Teosinte originated from Mexico, and is still being
grown there in close proximity to corn. Since maize to maize gene flow is well
documented, scientists ask if maize to teosinte gene flow is possible and if
teosinte pollen can travel to corn crops. Donald and colleagues from the
Connecticut Agricultural Experiment Station start the investigation by
exploring "Some physical properties of teosinte (Zea mays subsp.
parviglumis) pollen." Their work appears in the latest issue of the
Journal of Experimental Botany.
Researchers measured properties of
pollen, such as water potential, settling speed, germination versus water
content, drying rates, and calculated pollen wall conductance. They found that
the smaller size of teosinte pollen could allow it to travel longer distances
from the source. However, they also found that teosinte pollen is 30-50% more
susceptible to dessication, which would lessen the likelihood of teosinte
outcrossing into conventional maize varieties.
The data can be helpful
in establishing the main factors influencing the degree and the direction of
pollination between teosinte populations and between maize and teosinte.
Researchers also surmise that their findings can increase current
understanding of the gene-flow process in Mexico and Central America, where
teosinte and maize populations are still being grown near each other, and
flower together.
Subscribers to the Journal of Experimental Botany can
read the article at http://jxb.oxfordjournals.org/cgi/content/full/56/419/2401.
Other readers can take a look at the abstract at http://jxb.oxfordjournals.org/cgi/content/abstract/56/419/2401.
From
CropBiotech Update 23 September 2005:
Contributed by Margaret
Smith
Dept. of Plant Breeding & Genetics
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1.13 Genetic improvement for tolerance to phosphorus deficiency in
rice
Ping Wu
Phosphorus (P) is an essential macronutrient
for crops. Most phosphorus (P) compounds exist as either insoluble inorganic
phosphate (Pi) or organic phosphate; however, the availability of Pi and the
use efficiency of P fertilizers applied to the crops are extremely low in most
of soils. The use of P fertilizer is unsustainable and causes soil and water
pollution. Phosphorus is also a nonrenewable resource. By some estimates,
world resources of inexpensive P may be depleted by 20501.
Consequently, improvement of Pi uptake and use by crops is critical for
economic, humanitarian, and environmental reasons.
Plants have
developed many physiological and biochemical systems of adaptation to
Pi-deficiency stress. Thousands of genes, including many transcription
factors, can simultaneously be regulated by Pi-deficiency stress in
rice2, indicating that plant adaptation to Pi-deficiency is
systemic. Based on biochemical and transcriptional analysis, several
adaptation systems have been revealed, including enhanced uptake ability
through activation of high affinity transporters and adaptative root
development; induction of phosphate scavenging and recycling enzymes;
induction of alternative pathways of cytosolic glycolysis; induction of
tonoplast H+-pumping pyrophosphatase; and alternative pathways of
respiratory electron transport. The fact that many of the molecular and
biochemical changes in response to Pi-deficiency occur in synchrony suggests
that the genes involved are coordinately expressed and share a common
regulatory system. A specific Pi-signaling pathway and regulation system in
rice has been revealed3, which makes it scientifically feasible to
modify some key regulator(s) controlled by the specific Pi-signaling pathway
to enhance the uptake and use efficiency of Pi through genetic
engineering.
We found a transcription factor, with a Pi-deficiency
responsive bHLH domain, in rice roots obtained from a cDNA library constructed
by the Suppression Subtractive Hybridization (SSH) method. We cloned the gene,
designated OsPTF1 (Oryza sative L. phosphate transcription
factor), from an indica landrace rice variety Kasalath, which is Pi-deficiency
tolerant. Using Agrobacterium-mediated transformation, we introduced
the transcription factor into Oryza sativa cv. Nipponbare, which is
sensitive to Pi-deficiency. Our experiments demonstrated that transgenic rice
overexpressing OsPTF1 under the control of CaMV 35S showed enhanced
tolerance to Pi-deficiency under both solution culture and soil
experiments4 When grown in Pi-deficient
conditions, the genetically modified (GM) rice plants produced longer roots
and higher root biomass. About 30 percent more phosphate
was absorbed by the GM rice plants than the wild type rice plants in the same
environment.
To investigate the downstream genes regulated by
OsPTF1, a microarray analysis was performed using rice whole genome
oligo chips. Total RNA was extracted from 15d-old seedlings of the GM rice
plants and the wild-type seedlings under Pi-supplied condition (10 mg
Pi L-1). The sampling design is based on the fact that the plant
PHO genes are induced only under Pi-deficiency conditionif the PHO genes
can be induced under Pi-supplied conditions in the GM rice plants, then the
overexpressed OsPTF1 should function in the induction. Quantitative PCR
was used to confirm the differentially-expressed genes identified by the
microarray analysis.
A high degree of concordance (r = 0.87) was
observed between the results generated by the two methods. The microarray data
showed that 158 genes, with a ratio greater than 2-fold in roots and/or in
shoots, were found to be regulated by the overexpression of OsPTF1. The
function-classified genes include nutrient transporters and metabolism, carbon
metabolism, transcription factors, ATP-binding protein, oxidoreductase,
protease, disease resistance protein, RNase, H+-transporting
ATPase, vacuolar H+-pyrophosphatase, senescence-associated protein,
receptor-like kinase, and several cytochrome P450 genes. Many "function
unknown" or putative genes were strongly up- and down-regulated by
overexpression of OsPTF1. Some of them did not respond to
Pi-starvation4. The remarkable induction of the PHO genes, like
RNS1 and H+-transporting ATPase, in the GM rice plants under
Pi-supplied condition strongly suggests that overexpression of OsPTF1
triggers a rescue system in response to Pi-starvation and plays a role in the
increased tolerance to Pi-deficiency.
The bypass pathways, which
replace Pi-requiring and adenylate-requiring enzymes using
pyrophosphate-dependent and NADP-dependent enzymes, are considered important
in maintaining carbon flux under Pi-starvation. Phosphoenolpyruvate (PEP)
plays a central role in the modification of carbon and energy metabolism in
response to Pi-starvation. In the cytosol, PEP can be converted to pyruvate
catalyzed by pyruvate kinase (PK) or to oxaloacetate (OAA) catalyzed by PEP
carboxylase (PEPC). The latter has been suggested to be a Pi-starvation
induced bypass to preserve Pi. In this study, we did not find the gene for
PEPC to be regulated, but a gene for PEP carboxykinase was up-regulated by
Pi-starvation and overexpression of OsPTF1 in the shoots. PEP
carboxykinase catalyzes the conversion of phosphate and OAA to PEP and
CO2. The results suggest that the stimulation of recycling of the
original metabolic pathways should be important in alleviating Pi-deficiency
conditions, which was enhanced by the overexpression of OsPTF1.
Cloning of OsPTF1 may speed up the molecular breeding program
for crops with enhanced tolerance to Pi-deficiency; because OsPTF1 was
derived from rice rather than a different plant species, new rice varieties
containing the modified gene could be developed by combining traditional
breeding with molecular techniques. This study provides evidence that
modification of a key regulator involved in the Pi-signaling pathway may
exploit the potential ability of plants to more efficiently uptake Pi in
growth medium and utilize Pi in plants.
Acknowledgements The
author’s research is supported by the Key Basic Research Special Foundation of
China, Special Program of Rice Functional Genomics of China, National
Education Ministry of China, and Science and Technology Bureau of Zhejiang
province.
References
1. Vance C P et al. (2003)
Phosphorus acquisition and use: Critical adaptations by plants for securing a
nonrenewable resource. New Phytologist 157, 423-447
2. Wasaki
J et al. (2003) Transcriptomic analysis of metabolic changes by
phosphorus stress in rice plant roots. Plant, cell and Environment
26, 1515-1523
3. Hou XL et al. (2005) Regulation of the
expression of OsIPS1 and OsIPS2 in rice via systemic and local Pi signaling
and hormones. Plant Cell and Environment 28: 353-364
4. Yi KK
et al. (2005) OsPTF1, a novel transcription factor involved in
tolerance to phosphate starvation in rice (Oryza sativa L.). Plant
Physiology, online
Ping Wu
State Key Lab. of Plant Physiology and
Biochemistry
College of Life Science, Zhejiang University
Hangzhou,
310029, China
clspwu@zju.edu.cn
Source:
ISB News Report
September 2005
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1.14 Thai breeders develop GM breeds
of jasmine rice tolerant to flooding, bacterial leaf blight and leaf
blast
Bangkok, Thailand
By Pongpen Sutharoj, The Nation via Checkbiotech
To improve rice
quality and yields, the National Centre for
Genetic Engineering and Biotechnology (Biotec) has developed new breeds of
jasmine rice that are tolerant of drought, pests and disease.
The new
rice breeds are the result of a research project on rice genomes.
Understanding the rice genome will help scientists to develop new rice
varieties with traits such as higher yield, improved nutrition content, and
better resistance to diseases and pests.
Biotec’s director Morakot
Tanticharoen said the centre’s researchers had applied information from the
International Rice Genome Sequencing Project, which cracked the genome of the
Japanese aromatic rice Nipponbare, to develop new breeds of Thai rice.
The International Rice Genome Sequencing Project is a collaborative
project among 10 nations to break the genetic code of rice. Thailand is also
one of the participants, along with the United States, Japan, Canada, Taiwan,
South Korea, Britain, France, Brazil and India.
The results of the
study have been put in the public domain, so any country can use them in its
own developments.
Morakot said the researchers used the information to
further develop jasmine rice. Even though the rice genome information in the
project is based on Japanese rice, she said the genome information could also
be adapted to other species including jasmine rice, as the DNA structures of
individual rice species do not vary greatly.
The centre has studied
sequence data from the project to develop a new breed of rice that can resist
flooding, a major problem for rice farmers as it causes damage and loss of
productivity.
Morakot said the new breed has already been tested in
many provinces and the result was satisfactory. “We found that our new breed
can resist flooding well. It offers higher productivity at 303 kilograms per
rai, compared to the old breed that provides only 50 kilograms per rai,” she
said.
In addition to flood tolerance, the centre has also developed
two other breeds of jasmine rice.
They can resist bacterial leaf
blight and leaf blast disease, which are major threats.
The director
said the two breeds were also being tested. However, to further improve
jasmine rice, the team is now working to combine three key traits - resistance
to drought, bacterial leaf blight, and leaf blast disease - into one breed so
the new breed could tolerate every situation. The project is likely to move
into field trials next year.
From the study of rice genomes, Morakot
said the research team could also understand the DNA sequence of jasmine rice
that offered its unique fragrance.
“From this knowledge we can develop
a process to turn rice with no fragrance into fragrant rice,” she said.
The centre has submitted a patent registration for the process and
it’s now waiting for approval. The centre also plans further study on rice
genomes to give rice special qualities, for example finding genes related to
the quality of rice when cooked in different ways.
This, Morakot said,
would bring more added value to Thai rice for export.
© 2000 Nation Multimedia
Group
Source: SeedQuest.com
2 September 2005
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1.15 UCR biochemist goes to Washington with high-protein
corn
Daniel Gallie’s findings propose a useful approach to feed the
world’s growing population
RIVERSIDE, Calif. – Corn with twice its
usual content of protein and oil and about half its usual carbohydrate content
is what Daniel
Gallie, professor of biochemistry, will present at a congressional seminar
in Washington, D.C., this week.
Because his research holds promise for
efficiently feeding high-protein corn to people and livestock all over the
world, Gallie has been invited to speak to an audience of congressional staff
in the Longworth House Office Building of the U.S. House of Representatives.
His 45-minute presentation is scheduled for 10 a.m., Sept. 23.
The
National Coalition for Food and Agricultural Research, a broad-based coalition
of agricultural producers, science societies and universities, is sponsoring
the seminar.
In the United States, the vast majority of corn – nearly
65 percent – is used to feed animals for meat production. Much of the
remainder is exported to other countries for feeding animals or made into corn
sweeteners or fuel alcohol. Corn, the most widely produced feed grain in the
United States, accounts for more than 90 percent of total value and production
of feed grains in the country, with around 80 million acres of land planted
with corn.
Gallie’s research on doubling the protein content of corn
grain adds significant value to the crop, benefiting corn producers. Moreover,
his technology nearly doubles corn oil, the most valuable content of corn
grain, and significantly increases the grain’s value. Corn is processed also
into other food and industrial products such as starch, sweeteners, beverage
and industrial alcohol, and fuel ethanol.
“Nearly 800 million people
in the world suffer from protein-energy malnutrition, which is a leading cause
of death in children in developing countries, many of which already produce
corn as a major cereal crop,” said Gallie. “A significant fraction of the
world’s population, particularly in developing countries, has no access to
meat as a protein source, and has to rely on plant sources such as grain. The
new corn we have developed has two embryos in its kernel, which is what
doubles the content of protein and oil and reduces the starch content. It
could provide a good source of protein for those that depend on grain as their
primary source of nutrients.”
Every corn kernel results from a flower
on an ear of corn, Gallie explained. Initially the ear produces a pair of
flowers for every kernel. But then one of the sister flowers undergoes
abortion, resulting in one flower for each kernel. Gallie’s research group has
developed technology that essentially rescues the aborted flower, resulting in
two kernels that are fused together. “Despite the fusion, the kernels are not
bigger,” Gallie said. “It’s basically the same corn, except that it is
protein-rich and starch-poor – something that, if applied to sweet corn, would
appeal to a large number of weight-conscious people in this country who are
interested in low-carb diets and who normally avoid corn in their diets.”
Gallie and his colleagues published their work last year in The Plant
Journal. Though their research focused on feed corn, the technology can easily
be applied to sweet corn, a sugar-rich mutant strain of regular corn.
The U.S. Department of Agriculture, the National Science Foundation,
and the California Agricultural Experiment Station funded the research.
Details of the study:
Flowers in the corn ear develop in
pairs but one from each pair aborts before pollination can occur. Because of
the role cytokinin, a plant hormone, plays in preventing organ death, Gallie’s
research group introduced a gene that enabled production of cytokinin, thus
rescuing the flowers. The kernels produced from pairs of flowers fused into a
single normal-sized kernel that contained two embryos and a smaller endosperm,
the food storage tissue that provides nutrients to the developing embryo.
Because the embryo contains the majority of protein and oil, two embryos in
the kernel doubles the protein and oil content in corn grain. The nutritional
value of the grain improves also because the size of the endosperm, which
contains most of the carbohydrates, is reduced.
Source:
EurekAlert.org
20 September 2005
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1.16 Australian breeders develop new phytophthora root rot resistant variety by crossing chickpea with a wild
cousin
Australia
Australia’s chickpea growers could enjoy higher
yields from a new phytophthora root rot resistant variety developed by
crossing chickpea with a wild cousin and this is just one possible way wild
relatives can improve crops.
Although chickpea can bring $A450 per
tonne in Western Australia, it is often ravaged by disease.
One such
disease is phytophthora root rot, which, according to Ted Knights, chickpea
breeder at Tamworth
Agriculture Institute, seriously threatens Australia’s chickpea industry,
with an estimated 100,000 hectares at risk this year.
“Affected areas
could suffer yield losses greater than 20 per cent at the regional level in
any one year and above 50 per cent at the grower level,” Mr Knights
said.
Working through the Centre
for Legumes in Mediterranean Agriculture (CLIMA) at the University of Western Australia, Fucheng Shan
(photo) and colleagues have studied all known annual wild relatives of
cultivated chickpea from the world’s gene banks to transfer a more diverse
genetic heritage into commercial crops.
Supported by the Grains Research and Development Corporation,
CLIMA has characterised the international family of about 200 annual wild
Cicer accessions using DNA markers.
“Knowledge of where these
wild species grow and their diversity has, effectively, mapped global ‘hot
spots’, making further collection and future research easier,” Dr Shan
said.
Dr Shan noted that the low genetic variation of chickpea, which
is the unique cultivated Cicer species, is one reason why global
chickpea yield improvement has been slower than in cereals.
“This
reinforces the necessity to introduce valuable genes from its wild relatives.
“Successful crop improvement depends on genetic diversity of
germplasm.
“Characterising the world’s wild Cicer collections,
using DNA markers, showed they have much wider genetic variation and are
potential gene donors to help chickpea win its battle against pests, diseases
and other constraints,” Dr Shan said.
Source: SeedQuest.com
14
September 2005
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1.17 Super resistance to tackle biggest wheat
disease
Canberra, Australia
From CSIRO Plant Industry -
e-newsletter Issue 11
Without rust resistant wheat varieties the
Australian wheat industry would lose up to $300 million per year in lost
production due to rust infection. CSIRO Plant
Industry’s Dr Rohit Mago (photo) has located four rust resistance genes
that he will use together to breed a super stem rust-resistant wheat – at
least four times more rust resistant than existing varieties. With four
resistance genes working together it is unlikely that a new strain of rust
will develop that will be strong enough to counter all four resistance genes
at once.
Dr Mago’s Canberra based research located the genes with
‘markers’, allowing breeders to more quickly and easily identify if their new
wheat variety has the rust resistance genes or not. Markers are critical when
using multiple genes as you can’t rely on testing the plant for resistance by
exposing it to rust as any one of the genes could provide initial resistance.
Three of the rust resistance genes were previously associated with negative
yield and quality traits, but their new versions appear to not have these
drawbacks.
Dr Mago has already bred plants with different combinations
of two resistance genes and now hopes to combine three and four genes in the
one wheat breeding line.
This collaborative research is supported by
the Grains Research and Development
Corporation (GRDC), Waite Institute in
Adelaide, South Australia and the Plant Breeding Institute in
Cobbitty, New South Wales.
PDF version: http://www.pi.csiro.au/enewsletter/PDF/PI_info_PyramidingRust.pdf
Scientific reference
Mago, R., et al (2005). Development of PCR
markers for the selection of wheat stem rust resistance genes Sr24 and Sr26 in
diverse wheat germplasm. Theoretical and Applied Genetics, Vol: 111,
Issue: 3
Produced by CSIRO Plant Industry Communication Group
2005
Source: SeedQuest.com
12 September 2005
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1.18 Higher rice yields with no extra water
Canberra,
Australia
From CSIRO
Plant Industry - e-newsletter Issue 11
Annual rice production
losses due to cold are 5 to 10 per cent, or $44 million, and when cold snaps
occur about every 4 years losses soar to up to 40 per cent. Water is used to
buffer cold-sensitive rice against cold – a cold tolerant rice variety could
reduce this water use.
CSIRO
Plant Industry research in Canberra has shown cold snaps prevent sugar in
rice being transported to the pollen. Pollen development is then aborted and
without pollen no grain is produced. There is a 1-2 day opportunity for sugar
to be transported from a layer surrounding the pollen to the pollen itself. If
a cold snap occurs then, there is no further chance for sugar to get to the
pollen to allow it to grow.
Dr Rudy Dolferus (photo) has found a gene
that produces a hormone that can prevent the development of one of the enzymes
that moves sugar to pollen. In conventional rice more of this hormone is
produced when it is cold, but in cold tolerant rice the hormone’s levels
remain the same – allowing the enzyme to develop.
Why this gene behaves
differently is now being investigated. If there is a difference in the gene
then DNA markers that flag its location can be identified – speeding up the
delivery of a cold tolerant rice variety.
This research was supported
by the Rice Cooperative Research
Centre.
PDF version: http://www.pi.csiro.au/enewsletter/PDF/PI_info_ColdTolerantRice.pdf
Produced by CSIRO Plant Industry Communication Group
2005
Source: SeedQuest.com
12 September 2005
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1.19 Why does salinity pose such a difficult problem for plant
breeders?
Brighton, United Kingdom
Saline soils and salt
water have become more and more dominant through the centuries, and naturally
occurring salt-affected soils are estimated to cover a billion hectares
worldwide. Scientists are thus trying to duplicate – but to little success – what Nature has done for some trees, shrubs, grasses, and herbs: allow plants
to be salt-tolerant. In light of this problem, T.J. Flowers and S.A. Flowers
of the University of Sussex ask, “Why
does salinity pose such a difficult problem for plant breeders?” Their review
appears in the September issue of the Agricultural Water Management
journal.
Salt-tolerance, as it turns out, is a very complex genetic
trait. In the article, researchers recount most of the molecular mechanisms
underlying plant defenses against salty soils or water. This is accomplished
by the presence of organic compounds in plant cell cytoplasm, such as
glycinebetaine, mannitol and proline. Salt tolerance also depends on plant
morphology, compartmentation and compatible solutes, regulation of plant
transpiration, control of ion movement, plant cell membrane characteristics,
tolerating high Na/K ratios in the cytoplasm, and salt glands. With these many
factors, the authors expect that salt tolerance would depend on the action of
many genes.
With the rather daunting tasks ahead for bioengineers
seeking to produce salt tolerant plants, researchers recommend that plant
breeders “invest in other avenues such as the manipulation of ion excretion
from leaves through salt glands, the use of physiological traits in breeding
programs, and the domestication of halophytes.”
Subscribers to
ScienceDirect can read the complete article at http://dx.doi.org/10.1016/j.agwat.2005.04.015.
Source:
SeedQuest.com
9 September 2005
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1.20 ’Defender’ is first commercial potato in the United States
to resist late blight
Aberdeen, Idaho
Source: USDA/ARS Food & Nutrition Research Brief
Defender, a long, white-skinned potato from
ARS and university potato breeders, is
the first commercial potato in the United States to resist late blight, one of
the worst potato diseases worldwide
Long, white-skinned potatoes in
the produce section of your supermarket might be "Defender"the only
commercially grown potato in the United States today with tubers and leaves
that fend off late blight disease. Worldwide, late blight is generally
regarded as one of the worst diseases of potatoes.
Besides starring as
a fresh-market potato, Defender also can be processed into frozen products.
ARS scientists in the Small
Grains and Potato Germplasm Research Unit , Aberdeen, Idaho, and the
Vegetable and Forage Crop Research Unit, Prosser, Washington, worked with
university colleagues to in Idaho, Oregon and Washington develop this superior
spud. They put it through more than a decade of rigorous outdoor tests before
making it available to growers, processors, potato-seed companies and others
last year.
The plant's natural resistance to late blight allows
growers to use either no fungicidesor much smaller amountsto control
the disease. This feature makes the potato ideal for conventional and organic
farms alike.
Source: SeedQuest.com
7 September 2005
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1.21 New kidney bean germplasm line
resists common bacterial blight disease
Washington, DC
ARS News
Service
Agricultural Research Service, USDA
Jan Suszkiw, (301) 504-1630,
jsuszkiw@ars.usda.gov
A new
germplasm line dubbed "USDK-CBB-15" is now available for breeding new
varieties of dark red kidney beans that can resist common bacterial
blight.
Caused by the pathogen Xanthomonas axonopodis pv. phaseoli,
bacterial blight is an endemic disease affecting bean crops east of the U.S.
Continental Divide. Antibiotic treatment, clean-seed programs and sanitation
are standard control measures. However, resistant crops are the key defense,
according to Phil Miklas, a plant geneticist in the Agricultural Research
Service's (ARS) Vegetable and Forage Crops Production Research Unit in
Prosser, Wash.
In susceptible bean plants, the disease symptoms include
large brown blotches with lemon-yellow borders on leaf surfaces and small,
discolored seed in infected pods. Severe outbreaks can cause yield losses of
up to 40 percent in susceptible crops.
Miklas developed USDK-CBB-15
using marker-assisted selection, a method of detecting inherited genes that
speeds the screening of plants for desired traits such as disease resistance.
USDK-CBB-15 is the product of kidney bean crosses that Miklas made to
incorporate resistance genes from the Great Northern bean cultivar "Montana
Number 5" and the breeding germplasm line XAN 159.
James Smith, in
ARS' Crop Genetics and Products Research Unit at Stoneville, Miss., and Shree
Singh, with the University of Idaho at Kimberly, collaborated with Miklas on
the new kidney bean's development, testing and evaluation. They will post a
registration notice with detailed information on USDK-CBB-15 in an upcoming
issue of the journal Crop Science. Miklas is handling seed
requests.
The United States is the sixth-leading producer of edible dry
beans, generating farm sales of $451 million in 2001-03, according to the U.S.
Department of Agriculture's Economic Research Service. Per-capita consumption
of edible dry beans is 6.8 pounds, according to ERS, with kidney beans finding
favor in soups, salads, chili and other dishes. Beans are also an excellent
source of antioxidants, fiber, protein, and vitamins for healthy diets, Miklas
notes.
ARS is USDA's chief in-house scientific research
agency.
Source: SeedQuest.com
22 September 2005
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1.22 Hybrid grass may prove to be
valuable fuel source
CHAMPAIGN, Ill. -- Giant Miscanthus
(Miscanthus x giganteus), a hybrid grass that can grow 13 feet high, may be a
valuable renewable fuel source for the future, researchers at the University
of Illinois at Urbana-Champaign say.
Stephen P. Long, a professor of
crop sciences and of plant biology, recently took that message to Dublin,
Ireland, where the British Association for the Advancement of Science
sponsored the annual BA Festival of Science Sept. 3-10.
Closer to
home, two of Long's doctoral students, Emily A. Heaton and Frank G. Dohleman,
delivered their Miscanthus findings at the 49th annual Agronomy Day, held on
campus Aug. 18 and attended by more than 1,100 visitors from across the
Midwest.
"Forty percent of U.S. energy is used as electricity," Heaton
said. "The easiest way to get electricity is using a solid fuel such as coal." Dry, leafless Miscanthus stems can be used as a solid fuel. The
cool-weather-friendly perennial grass, sometimes referred to as elephant grass
or E-grass, grows from an underground stem-like organ called a rhizome.
Miscanthus, a crop native to Asia and a relative of sugarcane, drops its
slender leaves in the winter, leaving behind tall bamboo-like stems that can
be harvested in early spring and burned for fuel.
Rhizomatous grasses
such as Miscanthus are very clean fuels, said Dohleman, who is studying for a
doctorate in plant biology. Nutrients such as nitrogen are transferred to the
rhizome to be saved until the next growing season, he said.
Burning
Miscanthus produces only as much carbon dioxide as it removes from the air as
it grows, said Heaton, who is seeking a doctorate in crop sciences. That
balance means there is no net effect on atmospheric carbon dioxide levels,
which is not the case with fossil fuels, she said.
Miscanthus also is
a very efficient fuel, because the energy ratio of input to output is less
than 0.2, Heaton said. In contrast, the ratios exceed 0.8 for ethanol and
biodiesel from canola, which are other plant-derived energy sources.
Besides being a clean, efficient and renewable fuel source, Miscanthus
also is remarkably easy to grow. Upon reaching maturity, Miscanthus has few
needs as it outgrows weeds, requires little water and minimal fertilizer and
thrives in untilled fields, Heaton said. In untilled fields, various wildlife
species make their homes in the plant's leafy canopy and in the surrounding
undisturbed soil.
Illinois researchers have found that Miscanthus
grown in the state has greater crop yields than in Europe, where it has been
used commercially for years, Long said. Full-grown plants produce 10-30 tons
per acre dry weight each year. Miscanthus yields in lowland areas around the
Alps, where the climate is similar to the Midwest, are at least 25 tons per
acre dry weight, wrote Heaton and colleagues in a paper published in 2004 in
the journal Mitigation and Adaptation Strategies for Global Change.
Last year, Illinois researchers obtained 60 tons per hectare (2.47
acre), Long said at the BA Festival of Science.
Using a computer
simulator, Heaton predicted that if just 10 percent of Illinois land mass was
devoted to Miscanthus, it could provide 50 percent of Illinois electricity
needs. Using Miscanthus for energy would not necessarily reduce energy costs
in the short term, Heaton said, but there would be significant savings in
carbon dioxide production.
The Illinois Miscanthus crop began three
years ago when Heaton planted 400 Miscanthus rhizomes, which were generated
from three rhizomes donated by the Turfgrass Program in the department of
natural resources and environmental sciences. Because Miscanthus is sterile,
cuttings of Miscanthus rhizomes must be used to create new plants.
Now
in their third year, the three 33-by-33 feet Miscanthus plots at the
intersection of South First Street and Airport Road in Savoy, Ill., are
considered mature. Their 10-foot tall stems are twice as high as switchgrass,
a prairie grass native to Illinois. Grown side by side, Miscanthus produces
over twice as much biomass as switchgrass, Heaton said.
To investigate
how Miscanthus is so productive, Dohleman and others take measurements of
photosynthesis throughout the day. He measures the intensity of the sun and
then places a leaf in a chamber, allowing him to measure the rate of
photosynthesis depending upon ambient sunlight. Preliminary results show that
Miscanthus has a 27 percent greater rate of photosynthesis at midday compared
with switchgrass.
Nine different fields across the state are being
used to help estimate Miscanthus productivity, Heaton said. Plots in Champaign
and Christian counties each have more than 2 acres of Miscanthus, and DeKalb,
Pike, Pope, Wayne, Fayette and Mason counties have smaller plots. Plots in
Champaign County have shown the greatest yearly yields, according to Long's
2004 progress report to the Illinois Council on Food and Agricultural
Research, which funded the experiments.
"It is my hope that Illinois
will take the lead in renewable energy and that the state will benefit from
that lead," Long said.
Other varieties of Miscanthus have been grown
successfully in Indiana, Michigan and Ohio. However, the giant Miscanthus
being grown by the Illinois researchers has the greatest potential as a fuel
source because of its high yields and because it is sterile and cannot become
a weed, Heaton said. "Miscanthus sacchariflorus and some of the other fertile
Miscanthus species can be quite invasive," she said.
At a research
station near Hornum, Denmark, giant Miscanthus has been grown for 22 years in
Europe's longest-running experimental field. The crop has never been invasive
and rhizome spread has been no more than 1.5 meters (4.92 feet), said Uffe
Jorgensen, senior scientist for the Danish Institute of Agricultural Sciences.
The next step, Long said, is to demonstrate how Miscanthus goes from a
plant to a power source. Existing U.S. power plants could be modified to use
Miscanthus for fuel as in Europe, he said.
Long collaborates with
researchers at the Institute of Genomic Biology to study whether Miscanthus
could be converted to alcohol, which could be used as fuel.
Source:
EurekAlert.org
27 September 2005
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1.23
New high sugar grass released
Perennial
ryegrass (Lolium perenne L.) is the main grass species used for feeding cattle
and sheep in temperate regions. Research at the Institute of Grassland and
Environmental Research (IGER) has shown that increasing the water-soluble
carbohydrate (sugar) concentration of perennial ryegrass alters nitrogen
partitioning in the rumen and so reduces the amount of nitrogen excreted to
the environment . The sugar grass concept works by
providing the rumen micro-organisms with an improved balance of nutrients in
freshly ingested herbage which helps their growth. These organisms are
digested later by gastric processes when they pass into the abomasum (or true
stomach) and their digestion products are taken up from the small intestine.
Increasing the sugar content of the herbage also leads to a reduction in fibre
content of the grass, thereby increasing intake. If improved nitrogen use
efficiency in the rumen and increase forage intake is sufficiently large,
these two characteristics of high sugar grasses lead to improving milk
production and liveweight gain in ruminants as well as environmental benefit.
AberStar is a high sugar variety newly recommended for use in the UK in 2005.
In an experiment at IGER, its mean sugar content over 21 harvests during 3
harvest years was 246 compared with 191 g/kg of dry matter for the old
IGER variety S23. It had the highest value for in vitro digestibility under
simulated grazing of all the varieties in UK National List trials.
AberStar resulted from a programme of research and breeding at
IGER funded by both government sources (Defra and BBSRC) and private industry
(Germinal Holdings Ltd.).
Contributed by Peter Wilkins
pete.wilkins@bbsrc.ac.uk
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1.24
Paper recounts research on salinity-tolerant
plants
Saline soils and salt water have become more and more
dominant through the centuries, and naturally occurring salt-affected soils
are estimated to cover a billion hectares worldwide. Scientists are thus
trying to duplicate - but to little success - what Nature has done for some
trees, shrubs, grasses, and herbs: allow plants to be salt-tolerant. In light
of this problem, T.J. Flowers and S.A. Flowers of the University of Sussex
ask, "Why does salinity pose such a difficult problem for plant breeders?" Their review appears in the September issue of the Agricultural Water
Management journal
Salt-tolerance, as it turns out, is a very complex
genetic trait. In the article, researchers recount most of the molecular
mechanisms underlying plant defenses against salty soils or water. This is
accomplished by the presence of organic compounds in plant cell cytoplasm,
such as glycinebetaine, mannitol and proline. Salt tolerance also depends on
plant morphology, compartmentation and compatible solutes, regulation of plant
transpiration, control of ion movement, plant cell membrane characteristics,
tolerating high Na/K ratios in the cytoplasm, and salt glands. With these many
factors, the authors expect that salt tolerance would depend on the action of
many genes.
With the rather daunting tasks ahead for bioengineers
seeking to produce salt tolerant plants, researchers recommend that plant
breeders "invest in other avenues such as the manipulation of ion excretion
from leaves through salt glands, the use of physiological traits in breeding
programs, and the domestication of halophytes."
Subscribers to
ScienceDirect can read the complete article at http://dx.doi.org/10.1016/j.agwat.2005.04.015.
From
CropBiotech Update 23 September 2005:
Contributed by Margaret
Smith
Dept. of Plant Breeding & Genetics
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1.25 Fungus confers salt resistance to plants
The
Indian Thar desert is home to Piriformospora indica, a
plant-root-colonizing fungus recently found to promote plant growth. Its hosts
include rice, wheat, and barley, and research has shown that "The endophytic
fungus Piriformospora indica reprograms barley to salt-stress
tolerance, disease resistance, and higher yield." Frank Waller of the
University of Giessen, Germany and colleagues document their work in the
latest issue of the Proceedings of the National Academy of Sciences
online.
Using barley as their model organism, researchers allowed P.
indica to colonize roots, then subjected the plants to salt stress and
disease stress. Among others, they found that P. indica colonizes root
cells and enhances yield; roots show higher antioxidant capacity; and
colonization induces systemic disease resistance, protecting barley leaves
from other fungal infections.
Read the complete article at http://www.pnas.org/cgi/content/full/102/38/13386.
From
CropBiotech Update 23 September 2005:
Contributed by Margaret
Smith
Dept. of Plant Breeding & Genetics
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1.26
Washington State University researchers find a key to
plant growth
Pullman, Washington
Waist-high corn stalks
laden with full-size ears; squash plants that don't sprawl over half your
yard; a miniature tomato plant offering hefty red fruits to astronauts weary
of freeze-dried food: these are just a few of the possibilities raised by new
research at Washington State
University.
Lead investigator B.W. (Joe) Poovaiah and research
associate Liqun Du have discovered a way to control the ultimate size of a
plant. By altering a specific gene, they were able to change the size of the
plant that grew from an experimental seed. Different alterations led to
different size plants, showing that plants might be "size-engineered" to fit
the needs of growers.
Their findings are reported in this week's issue
of the prestigious journal Nature. WSU has
applied for a patent on the process.
Poovaiah said size-engineered
plants could be a potent tool against worldwide hunger.
"Dwarf plants
use less water and are more resistant to wind and rain damage than normal-size
plants," he said. "They devote a greater proportion of their energy to
producing seeds or fruit rather than stems and leaves."
He compares his
findings to the development, in the 1960s, of semi- dwarf wheat varieties that
boosted Third World wheat production in what became known as the "Green
Revolution."
Poovaiah and Du worked primarily with Arabidopsis, a
member of the mustard family, but have found similar genes with the same
function in every plant they have examined, including important crop plants
such as peas and rice.
In addition to large-scale agriculture, other
potential uses for dwarf plants include ornamental horticulture, home gardens
and even the greening of space. Some of Poovaiah's earlier funding came from
NASA, to develop plants that will grow well -- but small -- within the
confines of a spacecraft, as a way to provide both oxygen and fresh food
during long missions.
The gene described in the Nature article directs
the plant to make a protein, dubbed DWF1 (for "Dwarf 1"), that is involved in
the production of a plant growth hormone. Poovaiah and Du showed that the
normal form of DWF1 is needed, along with calcium and a calcium-binding
protein called calmodulin, for a plant to attain its full normal size. When
they modified the gene in one way, the plant topped out at less than half of
normal height. Greater modification stunted the plant even further.
Eliminating the gene (and hence the protein) resulted in a ground-hugging
rosette of leaves with very little vertical growth.
The DWF1 gene is
just one of many genes that Poovaiah's lab has identified that function in the "calcium messenger system" in plants.
Calcium has long been known to be
crucial in animals for a wide range of processes, including muscle contraction
and the generation of nerve impulses, but its functions in plant biology have
been more elusive.
Over the past three decades, Poovaiah and his team
have shown that calcium and calmodulin are just as important in the internal
workings of plants.
In addition to controlling growth, Poovaiah says
the calcium messenger system enables a plant to adjust to water stress, light,
temperature and other environmental factors. In legumes, it also mediates the
interactions between roots and bacteria that lead to the transfer of nitrogen
from the air to the soil in a form that plants can use to build proteins and
other compounds necessary for life. A gene that Poovaiah's lab discovered in
1995 has recently been shown to play a key role in this process, which is
known as symbiotic nitrogen fixation.
Poovaiah is a professor in WSU's
Department of Horticulture and Landscape Architecture and the Center for
Integrated Biotechnology. The research described here was supported by grants
from the National Science Foundation and U.S. Department of Agriculture. More
information and photographs about Poovaiah's work can be found at his web
site, http://molecularplants.wsu.edu/calcium/.
Source:
SeedQuest.com
28 September 2005
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1.27
Plant genes 'offer safer option for GM crop
research'
Researchers have suggested a new way of genetically
modifying crops that they say could reduce a key concern about their safety.
In most genetically modified crops created so far, researchers have
inserted not only genes for traits such as insect resistance, but also a
bacterial gene for antibiotic resistance. This allows them to confirm in
laboratory tests that the inserted genes are present in the crop.
But
this practice has raised concerns that the genes for antibiotic resistance,
which come from bacteria, could find their way back into disease-causing
bacteria, making them antibiotic resistant too. In the case of an infection
with antibiotic-resistant bacteria, this could render conventional treatment
with antibiotics ineffective.
Research published in Nature
Biotechnology last week, however, shows that a plant gene can be used to
confer antibiotic resistance instead, limiting the chances of antibiotic
resistance spreading to wild bacteria.
The researchers say that how the
plant gene does this is not yet clear, but preliminary tests have shown that
inserting the plant antibiotic resistance gene into the bacterium E. coli
does not make the bacterium resistant to the antibiotic.
Source:
BBC Online / news@nature.com via SciDev.net
24 August 2005
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1.28
QTL detection and application to plant
breeding
Motoyuki Ashikari and Makoto Matsuoka
QTL
cloning for grain productivity and plant height
Rice (Oryza sativa
L.) is a staple food and approximately 50% of the human population depends on
rice as their main source of nutrition. In particular, it is the most
important crop for people living in the monsoonal areas of Asia where rice has
a long history of cultivation; it is deeply ingrained in the daily lives of
Asian people.
Rice is a model monocot because it has the smallest
genome size (390 Mb) among the major cereals, its genome is syntenic with the
genomes of other cereals, and it can be transformed easily. As a result, The
International Rice Genome Sequencing Project (IRGSP) was launched in 1998 to
sequence the rice genome; the task was completed in 2004. These
accomplishments and recent technological innovations have greatly facilitated
gene cloning and provided a new breeding strategy for rice as well as for
other major cereals.
In contrast to monogenic characteristics, such as
disease and insect resistance, many important agronomic traits including
yield, heading date, culm length, grain quality, and stress tolerance show
continuous phenotypic variation. These complex traits usually are governed by
a number of genes known as quantitative trait loci (QTLs) derived from natural
variations. Although these polygenic characteristics, including QTLs, were
previously very difficult to analyze using traditional plant breeding methods,
recent progress in rice genomics has made it possible to search
QTLs.
QTL analysis is a powerful approach to discover agronomically
useful genes. Grain number and plant height are important traits that directly
contribute to grain productivity. Why is plant height important for grain
production? Dwarf rice and wheat varieties were developed by classical plant
breeding methods, contributing to the green revolution in the 1960’s. Higher
yields were obtained from these dwarf crops because their short stature
reduced lodging from wind or rain1,2. Our lab has aimed to identify
genes of QTLs for grain number, Gn1, and plant height, Ph1, not
only to elucidate molecular mechanisms for grain productivity, but also to
utilize these genes for breeding3.
A choice of parental
lines that show wide phenotypic variation in the targeted traits is necessary
for QTL analysis because QTL detection is based on natural allelic differences
between parental lines. An indica rice variety, Habataki,and a
japonica variety, Koshihikari, were chosen in QTL analysis since not
only do they exhibit large differences in grain number and plant height, but
also many molecular markers are available. QTL analysis using progenies from
the cross with Habataki and Koshihikari revealed the presence of five QTLs for
increasing grain number (Gn1-5) and four QTLs for plant height
(Ph1-4). The most effective QTLs for grain number, Gn1, and
plant height, Ph1, were chosen as targets for cloning.
QTL
cloning is facilitated by using nearly isogenic lines (NILs) carrying only one
target QTL, because NIL can eliminate the effects of other QTLs. By using a
suitable NIL, the QTL of interest in the NIL can be treated as a single
Mendelian factor. We produced the NIL-Gn1 and NIL-Ph1 lines
carrying the Gn1 or Ph1 region from Habataki in the Koshihikari
background and used these lines for cloning. Base on fine mapping analysis of
QTL-Gn1, we found that Gn1 could be divided as two linked QTLs
(QTL-Gn1a and QTL-Gn1b). We focused on the Gn1a, since it
could be mapped between two molecular markers.
Positional cloning and
molecular characterization revealed that Gn1a encodes a cytokinin
oxidase/dehydrogenase, OsCKX2, an enzyme that degrades a phytohormone
cytokinin. The OsCKX2 gene of Koshihikari and Habataki consists of four
exons and three introns and encodes proteins of 565 or 563 amino acids,
respectively. A comparison of the DNA sequences between the cultivars revealed
several nucleotide changes, including a 16-bp deletion in the 5’-untranslated
region, a 6-bp deletion in the first exon, and three nucleotide changes,
resulting in amino acid variation in the first and fourth exon of the Habataki
allele. Both OsCKX2 alleles of Habataki and Koshihikari encode an
enzyme capable of degrading cytokinin. However, the expression level of
OsCKX2 in Habataki was lower than in Koshihikari, resulting in less
cytokinin accumulation in the inflorescence meristems of Habataki than
Koshihikari. Cytokinin (CK) is known to influence various aspects of plant
growth and development, including seed germination, apical dominance, leaf
expansion, reproductive development, and delay of senescence. The reduced
expression of OsCKX2 can explain the increased cytokinin accumulation,
and hence, increased grain number. The semi-dominant inheritance of Gn1a
is also consistent with the function of the OsCKX2 enzyme that degrades
cytokinin.
On the other hand, Ph1 was located near the
sd1 gene that encodes gibberellin 20-oxidase. Comparing the sequence of
sd1 in the Habataki and Koshihikari alleles revealed that Habataki had
a 383-bp deletion in the SD1 gene, which is the same mutation found in ‘IR8’, a variety that led to the green revolution in rice. This observation
demonstrated that the short stature of Habataki mainly depends on the sd1
locus3.
QTL pyramiding breeding
QTL pyramiding is
an efficient strategy for crop improvement. This strategy is based on the
combination of desirable QTLs through conventional crossing using molecular
markers. Once desirable QTLs are detected, a strategy for QTL pyramiding
employs the use of NILs harboring only one target QTL. The NIL-QTLs are
produced by backcrossing and marker selection. A parent line with a positive
QTL is backcrossed with a recurrent parent lacking the QTL. Subsequently, a
line that carries only a positive QTL region from the mother line in the
recurrent parent genome background is selected by molecular markers. The NILs
can be used to accurately evaluate the effect of each QTL individually. Once
QTLs with important effects are identified in this manner, the appropriate
NIL-QTLs are crossed to pyramid two or more QTLs in the same background. The
two NILs, the NIL-Gn1 and NIL-sd1, carrying the
Gn1 region or sd1 region from Habataki in the Koshihikari genome
background, were produced by backcrossing with Koshihikari and using marker
selection. We then derived a NIL-sd1+Gn1 plant with the two
desirable QTL alleles derived from the cross NIL-Gn1 and
NIL-sd1. The NIL-sd1+Gn1 has a high yielding, semi-dwarf
phenotype (Fig.1)3.
Future outlook
Food
shortage is one of the most serious global problems in this century. The world
population is expanding rapidly due to a significant decline in mortality
rates resulting from advancements in modern medicine and human health care,
while the availability of land for cultivation has dramatically declined as
the result of desertification caused by reckless deforestation and
construction. The global population, now at 6.4 billion, is still growing
rapidly and is projected to reach 8.9 billion people by 2050. Cereals are an
important source of calories for humans, both by direct intake and as the main
feed for livestock. Approximately 50% of the calories consumed by the world
population originate from three cereals, rice (23%), wheat (17%), and maize
(10%). To meet the expanding food demands of the rapidly growing world
population, crop grain production will need to increase by 50% by 2025.
Now that genomic information and tools are available for rice, we have
to apply these for human benefits. Today the cloning of genes and production
of transgenic plants are common technologies utilized in plant science. Such
technologies are very powerful and efficient strategies for producing ‘ideal’
crop plants. Actually, some transgenic crop plants with traits such as insect
resistance and herbicide tolerance have already been commercialized. Despite
concerns about the impact of GMOs on the environment and their safety to
humans, we think transgenic crops are necessary to meet the demand for food in
the near future. However, we should not ignore the conventional breeding
approachthe QTL pyramiding approach results from a combination of recent
crop genomics and conventional breeding, and it is efficient for crop
breeding. We believe both strategies, GMO strategies and QTL pyramiding, are
necessary and the cooperation of molecular geneticists and breeders is
required to accomplish this goal.
References
1. Peng et
al. (1999) Nature 400, 256–261
2. Sasaki et al.
(2002) Nature 426, 701–702
3. Ashikari et al.(2005)
Science 309, 741-745
Motoyuki Ashikari and Makoto
Matsuoka
Bioscience and Biotechnology Center
Nagoya University, Nagoya
464-8601, Japan
makoto@agr.nagoya-u.ac.jp
Source:
ISB News Report
September 2005
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1.29
CSIRO's gene silencing granted US
patent
Australia
A CSIRO
innovation for determining gene function quickly and with virtually 100 per
cent efficiency has been granted a US patent clarifying its leadership
position in the international gene silencing arena.
Hellsgate, named
after one of its developers Dr Chris Helliwell, is a set of RNAi vectors that
allow researchers to knock out the expression of hundreds to thousands of
selected genes, one at a time.
“RNAi vectors are very hard to make, but
with Hellsgate, which uses Gateway™ technology, you can make either one or up
to 100 hairpin constructs from start to finish in just two days,” says CSIRO
Plant Industry Business Development Manager Dr Bill Taylor.
The
molecular tool is just one of a family of CSIRO-developed vectors designed to
simplify the use of hairpinRNAi – CSIRO's gene silencing technology – in
functional genomics and trait development and the first to be granted a US
patent.
“We're seeing a lot of interest in Hellsgate and its
vector-siblings, Stargate and Watergate, by the plant research community in
particular with more than 2,000 distributed to research labs around the
world,” says Dr Taylor.
“A major focus for many of these researchers is
the discovery of genes responsible for key traits, such as resistance to pests
and diseases or the ability to grow in hostile environments.
“Hellsgate
is the technology of choice to confirm gene function so that breeding of new
varieties can be based on genes with proven function.”
Dr Taylor says
the effectiveness of the CSIRO invention is highlighted by the use of a
Hellsgate vector by the Arabidopsis Genomic RNAi Knock-Out Line Analysis
(AGRIKOLA) consortium.
The European research consortium is using the
vectors to create a library of constructs for every gene in Arabidopsis, a
small plant used extensively in research because of its short life cycle of 21
days.
Hairpin RNAi was discovered by CSIRO by a CSIRO Plant Industry
team including Dr Peter Waterhouse and Dr Ming-Bo Wang, and is a highly
efficient method of triggering gene silencing.
The technology
works through a natural surveillance system that detects and destroys double
stranded RNA in cells. The Hellsgate vectors deliver double stranded hairpin
RNA molecules corresponding to each selected gene, thereby destroying the
messenger RNA for that gene and preventing its expression, silencing the
gene.
CSIRO is actively licensing its RNAi technology for applications
in research and the development of commercial products.
Source:
SeedQuest.com
5 September 2005
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1.30
Salt-tolerance gene could lead to higher rice
yields
By Zhang Jun, English.eastday.com via Checkbiotech
A group of
local scientists announced yesterday they have found and cloned a key genetic
code in rice that is responsible for salt-tolerance - a breakthrough that
could eventually lead to higher yields.
The group's findings were
published on the online version of "Nature
Genetics" - a UK-based scientific journal - on Sunday and the print issue
will be published next month, scientists said.
"Hopefully, our
research can speed up the country's development of high-yielding rice
species," said Lin Hongxuan, a professor at the Shanghai Institute of Plant Physiology and
Ecology - an arm of the Chinese Academy of Sciences.
Funded by
both the central and Shanghai governments, Lin and more than 13 researchers
and students spent the past five years completing the project, which they say
is a key achievement in the country's agricultural development.
The
group was also supported by researchers from the University of California.
During the past five years, Lin and his companions traced the genetic material
in six generations of a specially grown hybrid rice.
Each generation
took around half a year to grow, Lin said.
By a technique called "precise location," they finally found and cloned the SKC1 gene, which is
responsible for salt-tolerance in rice.
Lin said soil with a high salt
content can severely affect rice yields, particularly in some coastal areas
and the country's northwest regions. Under extreme conditions, it can even
reduce rice yields by more than 50 percent.
"Normally, it will take
several years for agricultural experts to utilize the discovered gene to
optimize rice species and to lift rice yields," Lin said.
He said it
might be possible to use the breakthrough to create a genetically modified
species of rice.
As the most important grain crop, rice sustains half
of the world's population. Improving yields could solve world hunger problems.
According to Wang Guozhong, head of the Shanghai Agricultural
Technology Service Center, the discovery will speed up efforts to lift rice
yields in the country, although high salt levels aren't a problem for local
farmers.
"The discovery is very enlightening and will help farmers
increase rice yields in rural areas," he said.
Copyright English.eastday.com
Source:
SeedQuest.com
13 September 2005
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1.31
How many genes influence plant growth?
Jena,
Germany
Identification and characterization of genes contributing to
quantitative traits is of utmost importance for plant breeding. Such genes are
called quantitative trait loci (QTL). Scientists from the Department of
Genetics & Evolution of the Max Planck
Institute for Chemical Ecology have now shown that a multitude of QTL
influence growth of the model plant Arabidopsis thaliana. Most of these QTL
have only minor effect but interact in a complex fashion.
A random
210,000 base pair segment from the Arabidopsis genome was chosen to
investigate the influence of allelic variation within this interval on plant
growth rate. The interval was dissected in a series of crosses between
near-isogenic Arabidopsis lines such that the progeny from each cross
segregated in different, very small portion of the genome but not in the
flanking regions. Plant growth was determined for more than 7,000 progeny from
these crosses. Within this small 210,000 base pair genome segment, two growth
rate QTL were identified and, in one case, the responsible gene was cloned.
Furthermore, both QTL interacted with other (still unknown) genes in the
genome, and phenotypic effects were reversed depending on the genetic
background.
Therefore, very many genes, albeit mostly of moderate
effect, determine the genetic architecture of complex traits like plant growth
or crop yield. In this view, breeding success depends less on selecting single
favorable genes but rather on finding the optimal combination of naturally
occurring variation within a species.
Jürgen Kroymann, Max Planck Institute for Chemical
Ecology
Source: Newsletter PULSE-CE of the Max Planck Institute for Chemical Ecology via
SeedQuest.com
9 September 2005
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1.32
Haploid cell lines in sugar beet
breeding
Gynogenic sugar beet haploid cell lines where obtained
through ovule culture in a haplodiploidisation breeding program. N6 culture
medium containing NAA and BA at 0.5and 0.2 mg/l respectively, 0.1%
charcoal 6% sucrose and 0.8% agar was used for the initiation of the culture
which were kept in dark at 27C. The haploid embryogenic callus were
subcultured in N6 medium with the same hormonal composition but with only 3%
sucrose. These lines being maintained for several years have kept their
embryogenic capacity. These haploid cell lines are used in sugar beet double
haploid plant, somatic embryo production and gene transfer studies with the
doubling of microshoots/embryos' ploidy achieved by using invitro
colchicine treatment.
Submitted by Nasrin Yavari
SBSI Tissue
Culture Lab
nasrin_yavari@yahoo.com
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1.33 New strain of wheat rust appears
in Africa
Editor’s note: This article should call attention to
the need for continuing support for strong, long-term breeding programmes, in
order to solve problems such as this one, before economic losses become
serious.
NAIROBI, Kenya,
Sept. 8 - Biologists warned Thursday that a virulent new strain of a
previously controlled plant disease had emerged in East Africa and could wipe
out 10 percent of the world's wheat production if its spread is not
halted.
Black spores on a stalk of wheat
show the effects of the disease.
The disease, wheat rust, caused huge
grain losses and even famines in the first half of the 20th century. The new
strain was discovered in Uganda
in 1999 and has since spread to Kenya and Ethiopia,
damaging wheat crops there.
The fungus that causes wheat rust, Puccinia
graminis, produces a rusty color on the stem of wheat and slowly destroys the
plant. It was controlled in the late 1950's and 1960's through the
groundbreaking work of Norman Borlaug, an American who won the Nobel Peace
Prize in 1970 for developing high-yield grains that led to the green
revolution.
Dr. Borlaug, now 91, spoke at a news conference on
Thursday in Nairobi and called to draw attention to the new threat.
"Nobody's seen an epidemic for 50 years, nobody in this room except
myself," he said. "Maybe we got too complacent."
After the new strain
of fungus emerged - and was named Ug99, for Uganda 1999 - it seemed to
disappear for a couple of years. It re-emerged in Kenya in 2001 and in
Ethiopia two years later, said Ravi Singh, a plant pathologist with the
International Maize and Wheat Improvement Center, a nonprofit research group
that convened an expert panel to study the resurgent disease. The panel's
report, to which Dr. Borlaug contributed, was released at the news conference.
"It's spreading and that's why we're sounding the alarm now," Dr.
Singh said.
The fungus is spread by spores carried by the wind or on
the clothing of travelers. The panel's report warns that urgent action is
needed if the world's wheat producers are to be spared. A 10 percent reduction
in global wheat yield would mean a crop loss of 60 million tons, worth $9
billion, said Ronnie Coffman, chairman of the panel and a professor of plant
breeding and genetics at Cornell University.
"It is only a matter of
time before Ug99 reaches across the Saudi Arabian peninsula and into the
Middle East, South Asia and, eventually, East Asia and the Americas," the
report said.
A Global Rust Initiative has been set up in Nairobi to
monitor the progress of the disease and begin the process of breeding and
disseminating new resistant wheat varieties.
In the 1950's, wheat rust
devastated crops in North America, affecting three-quarters of some varieties.
Since then, scientists have worked to develop high-yielding varieties that
resist ever-emerging diseases.
Wheat grown in East Africa had been
resistant to the disease for the last 40 years. But the new strain has
decimated local varieties.
Industrial farmers grow most of Kenya's
wheat, and they have been spraying their crops several times a year to control
the fungus. But wheat rust could have a devastating effect in countries like
Ethiopia and India,
where local farmers grow the bulk of the wheat, and chemicals might prove too
costly.
Dr. Masa Iwanaga, the director general of the International
Maize and Wheat Improvement Center, said his organization had compiled 165,000
different genetic varieties of wheat over the years, giving scientists a head
start in searching for strains resistant to the new variety.
Source:
New York Times
9 September 2005
Contributed by Nilupa
Gunaratna
gunaratna@purdue.edu
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1.34
Role of plant gene in heat tolerance
studied
The greatest problems of plants in tropical climates are
drought and high temperature stress. The latter inhibits plant photosynthesis,
disabling nutrient accumulation and stunting plant growth. Plants have been
known to also accumulate certain chemical compounds under salinity, drought,
and temperature stress.
One of these chemicals, glycinebetaine (GB), is
the subject of a recent study, where Xinghong Yang and colleagues from the
Chinese Academy of Sciences Plant Physiology report that the "Genetic
Engineering of