To: '[email protected]'
Subject: biotechnology and forest genetic diversity: 16
I agree with Dr. Burdon [6 June] that there are incremental, unpredictable risks involved with all types of genetic modification, both 'conventional' and transgenic. However, it is important to acknowledge that those risks are managable if the technology is employed responsibly. In a way, we are fortunate to have experienced some large-scale disasters such as the corn blight, and various disease epidemics that have plagued monoclonal poplar plantations at various times in the past. These mishaps have graphically demonstrated the folly of excessive reliance on a narrow genetic base in our crops. I am usually careful not to make general statements about biotechnology risk, which is largely case-specific. However, if biotechnology results in a substantial narrowing of the genetic base of planting stock on a landscape scale, this will result in an increase in risk exposure compared to conventional forestry. Considerable effort and discipline will be required to ensure that multiple transgenic genotypes are carried through the development and approval process for each trait. Also, experience with clonal forestry should help identify optimal planting designs that maximize genetic diversity on the landscape while maintaining productivity and efficient management of plantations. One of the challenges will be to ensure that planting guidelines are followed, especially in situations where there are strong, short-term financial disincentives. This may be one barrier to sustainable implementation of biotech forestry in the developing world.
Steve DiFazio
349 Richardson Hall
Forest Science Department
Oregon State University
Corvallis, OR 97331-5752, USA
Email: [email protected]
http://www.fsl.orst.edu/tgerc/steved.htm
[To contribute to this conference, send your message to [email protected] For further information on the Electronic Forum on Biotechnology in Food and Agriculture see http://www.fao.org/biotech/forum.asp ]
-----Original Message-----
From: Biotech-Mod2
Sent: Wednesday, June 07, 2000 9:28 AM
To: '[email protected]'
Subject: Re: Terminator technology and forest trees: 17
Some comments on the very reasonable, cautionary views of Rollie Burdon [6 June ].
There is no question that use of a new technology involves risks. Nothing ventured nothing gained. This is by no means unique to biotech. The question is how are risks assessed during research, testing, and initial commercial deployment.
Genetically modified (GM) trees will only be used commercially after a number of years of testing on many sites. During this process the vast majority of transgenic lines are discarded....often up to 99%. Only those that are most stable and perform well are considered for commercial use.
In forestry we have the advantage that in most cases we will be introducing trees gradually as plantations are felled and replanted (in contrast to agriculture, where GM seed can be used on a large scale in a very short time period...as we have seen in the USA, Canada, and Argentina). Thus, after many years of research there are many additional years of gradual commercial use where performance and risk of unforeseen problems are assessed.
Although gene transfer does cause changes in physiology, the genomes of plants are highly redundant and resilient. Experience has shown that it is possible to find transgenic lines, if one screens and tests well, that behave normally after gene transfer--though the frequency of abnormality varies widely among transformation methods and species.
Dr. Burdon is certainly correct that the more genes used, the more transgenic lines must be assessed for normal growth and acceptable gene and phenotype expression. Those planning to introduce many genes must be prepared to test many lines.
Finally, one must consider risk in context. Is it more risky to introduce specific genes than to introduce and grow on a large scale monocultures of exotic species ? I think not. These new species have required many kinds of research and management over the years to learn to cope with unexpected problems, many of which continue (e.g. provenance, nutrition and hydrology, new pests and pathogens, escape into native ecosystems) [definition of "provenance": place where the forest or tree stand (which can be natural or artificial) is growing on which the seeds (or propagules) were collected...Moderator]. The level of risk involved in use of transgenic trees appears, at least to me, to be quite a bit smaller than the risks that are managed routinely as part of these programs.
The many transgenic trees produced around the world have demonstrated that transgenics can be produced that are highly stable and perform well--at least over the several years of research trials performed to date. But, they are not risk free, especially from the view of large scale, long-term commercial use. There is still much learning to do. We pursue transgenics because we seek their benefits and our experience to date indicates that we can manage their risks. However, we must be committed to careful, step by step assessment of performance and adaptability, as well as of ecological consequences--the same requirements that should apply to any good silviculture or breeding program.
Steve Strauss, Oregon State University, USA
[email protected]
[To contribute to this conference, send your message to [email protected] For further information on the Electronic Forum on Biotechnology in Food and Agriculture see http://www.fao.org/biotech/forum.asp ]