Conservation and Utilization of Oat Genetic Resources for Food and Fodder Production in Tibet Autonomous Region, China

by

Yang Qingshou

Agricultural Research Institute, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, Tibet, China

1. Oat Genetic Resources in Tibet

Oat is an ancient crop, and it has been generally accepted that oats originated from China. A short growing period and wide adaptation to different types of soil, climates and ecological conditions are the main characteristics of oat. Though the climate is harsh in the high altitude of Tibet, oat grows in all parts of Tibet, also wild types of oats are commonly seen.

In 1981, during the collection of oat genetic resources in Shannan Prefecture, cultivated types were not found, but wild types of oat were found widely in this area. They are distributed in the area where the altitude is below 4500 masl. During this collection and inventory, 11 sub-species of wild oat were reported. Many of these sub-species were transitional types of wild oat from covered seed to naked seed. In 1982, not only many wild types of oat were found, but also many cultivated types of oat were found in Changdu prefecture in the eastern part of Tibet. It was reported that these types of cultivated oats had been growing in the Jiangda county of Tibet for many years. The main characteristics of these cultivated types of oat were naked seed, but most of the small spikes were close to the wild type with twisted long awn. With further evaluation and appraisal, it was concluded that these new sub-species (mutations) had evolved directly from the primitive wild types of oat. In addition, in the BuoMi, ZuoGong county, another type of wild oat with tight spike and with small spike handle was found.

2. Main achievements and status of research on oat genetic resources in Tibet

2.1. Extensive investigation and collection

During the 1981~1984 large-scale investigation and collection of oat genetic resources various sub-species of oat and its relatives were found. Among them, 161 oat species belonging to Avena fatua, 5 of them were H. virescens of Helietotrichon von, and 4 of them belonged to close relatives of oats.

2.2. Main Progress and Achievements

Along with the extensive collection and inventory of oat genetic resources, extensive research on oat genetic resources has been carried out.

It was concluded that there were 11 different sub-species of oat in Tibet and research on the identification of cultivated types of oat were conducted.

Meanwhile, research on cross-breeding of oat was carried out. Cross-breeding between wild oat and winter wheat was done and new variety called FY-8 was developed, which has characteristics of strong disease resistance, wide adaptation, good quality of seed and good performance and yield. At present, it is being cultivated by many farmers in Tibet. Research on oat and durum wheat were also conducted to improve the wheat seed quality.

3. Distribution of oat genetic resources in Tibet

Wild oats in Tibet is locally called "You Bu" and is widely distributed. It is an annual crop with high stem and seed falls naturally when it is matured. Great adaptability and strong reproduction make it a very widely distributed wild weed for farming in Tibet. It can be seen near the fields, in the farm fields, along the roads and in some grassland fields. Its wide spread is mainly human-induced because people carry the seed with their grain and other farm products from one place to another. However, a naturally developed population of wild oat has not been found in Tibet. With increasing altitude, the height of the oat straw is reduced, the length of the awn is shortened, seed cover increases, number of the seed reduces, seeds get smaller and the spike becomes shorter (see Table 1). Wild oats with hairiness on the outside shell of the seed, edge of the leaf and plant stem, are extremely widespread  (see Table 2).

Most of the Tibet oats are wild types of genotype. They are distributed at an elevation between 2400-4500 m. Cultivated types of oat are often found in the counties of Jiangda, Gongjue in the eastern parts of Tibet. The upper limit of altitude is about 3000 m.

Table 1 - Agronomic characteristics of oats at different altitudes

Altitude (m)

< 3,000

3,000~3,500

3,500~4,000

> 4,000

Straw height ( cm)

120

105.818.0

102.517.8

100.318.5

Length of awn ( mm)

301

366

365

375

Cover of caryopsis ( mm)

252

234

233

212

Width of Cover of caryopsis ( mm)

7

570.6

590.8

610.8

The first cover of caryopsis (mm)

8.50.7

9.30.5

9.50.7

9.60.6

The second cover of caryopsis (mm)

8.50.7

9.70.9

10.30.8

10.61

4.Classification and distribution of oat in Tibet

In 1753, oat was given the Latin name Avena as the family under which, there were four species classified, A. nuda L., A. fatua L., A. sativa L. and A. steilis L. In 1958, three different species of oat were identified in China. However, classification of oat species is still being debated and some of the Chinese scientists suggested that oat can be classified into 18 different sub-species. Table 2 shows all the sub-species found in Tibet. There were altogether 21 different types.

5. Characteristics of oat genetic resources in Tibet

Common wild oats

More than 160 samples of common wild oats were examined and classified into 21 different types. Of which there were 5 types with light brown seed, which have the characteristic of loose inflorescence and hairiness of outer shell of the first and the second floret. These types account for 44%. There were 8 types with grey seed colour, which have the characteristic of loose inflorescence and hairiness of outer shell of the first and the second floret. These types account for 40%. There was 1 type with brown seed, with loose inflorescence and hairiness of

Table 2 - Classification of oats in Tibet

Grain

colour

Soft hair on outside shell

Inflorescence

The first seed

The second seed

Loose inflorescence.

( var.)

Side inflorescence

( var.)

Dark Brown

Hairiness

Hairiness

russa Z.Du

pilifra Z.Du

Dark Brown

Hairiness

Hairlessness or Hairiness at bottom of awn

brunnea Z.Du

badia Z.Du

Dark Brown

Hairiness at bottom of awn

Hairlessness

hinnulea Z.Du

Grey

Hairiness

Hairiness

fumosa Z.Du

cineracea Z.Du

Grey

Hairiness

Hairlessness

myochroa Z.Du

incana Z.Du

Grey

Hairiness at bottom of awn

Hairiness at bottom of awn

airoschistacea Z.Du

cieracea Z.Du

Grey

Hairlessness

Hairlessness

elbida Z.Du

tephra Z.Du

Yellow

Hairiness

Hairiness

ochracea Z.Du

caesariata Z.Du

Yellow

Hairiness

Hairiness at bottom of awn

cerina Z.Du

Yellow

Hairlessness

Hairlessness

alutacea Z.Du

epipsila Z.Du

Brown

Hairiness

Hairiness

atrobrunnea Z.Du

Purple

Red protect caryopsis

Chinese

Sangri

Sangria Z.Du

Purple

Transition to Nakedness

Chinese

Langxian

Langxiana Z.Du

 

 

outer shell of the first and the second floret. There were 8 samples with dark purple seed and 5 of them were transitional types from covered seed to naked seed.

Cultivated type

Most of the cultivated oats in Tibet are naked seed type. It was found in 1985 that the cultivated oat in Tibet has the characteristic of each awn of the oat being twisted, the bottom of the seed is smooth, stem height is 120-145 cm, the length of the awn is about 20mm, the caryopsis is around 15 mm and it has a loose inflorescence.

5.1.Experimental Test on the introduced varieties and local cultivars

During 1998-1999, 5 introduced oat varieties were tested in Lhasa. Oat varieties No. 1 and 2 were introduced from Inner-Mongolia and No. 3, 4, and 5 were introduced from Hebei Province. Two local cultivars Gongjue Oat and Jiangda Oat were collected during early 1980s from the eastern part of Tibet in Gongjue County and Jiangda County of Changdu Prefecture. All these varieties are naked varieties. Initially these varieties were introduced and tested for food purposes, but later it was found that the straw of these oats were better than barley and wheat for animal feed. Attempts were made to introduce these to the local farmers to grow for fodder purposes, but local farmers rejected them because in the central part of Tibet, traditionally farmers think that oat is "wild-weed". However, this experimental test was an attempt to select better varieties for farmers for fodder and food.

They were sown on March 30th, germinated on April 20th and tillering occurred on May 20th. The growing period of these varieties was from 132-150 days. Stem height ranged from 120-145 cm, the length of spike ranged between 20.7-25.4 cm. The 1000 kernel weight ranged from 21.9-20.9 g. The yields of these varieties ranged between 101.7-236.57 kg/mu. Meanwhile two local cultivars were also tested. They were sown on March 30th, germinated on April 16th and tillering occurred on May 10th. Compared with the introduced varieties, the germination date and tillering date of local varieties was 4 days and 10 days earlier, respectively. The growing period of these varieties was 110-127 days. Stem height ranged from 107-132 cm. Local varieties were earlier maturing with taller straw than the introduced oat varieties. However, the yields were much less than the introduced varieties, ranging from 89.1 – 127 kg/mu. Table 3 shows the main results of the trial.

Table 3 - Main Agronomic Charateristics of Introduced Oat Varieties and Local Cultivars

Contents

Item

Growing period (day)

Stem high

(cm)

length of spike

(cm)

1000 kernel weight (g)

Yields (kg/ha)

No.1

145

174.9

23.2

21.7

3548.55

No.2

132

68.2

20.7

20.9

1525.5

No.3

139

100.8

22.1

21.4

3282

No.4

137

132.1

21.9

21.6

2845.5

No.5

150

194.9

24.5

21.9

3312

GongJue oat

127

132.1

23.2

15.8

1905

JiangDa oat

118

118.9

21.2

14.7

1336.5

5.2. Experimental Test on comparing spring wheat, the introduced oat varieties and durum wheat in Tibet

After the first year test in Lhasa, three oat varieties No. 1, 2, and 3 gave a good yield. In order to further select the better cultivars and to use their potential in Tibet, further tests on these varieties were carried out. Another aim of this experiment was to see the quality of oat seed through comparing with common wheat and durum wheat.

Durum wheat is rarely grown in Tibet. However, the quality of grain of dominant common wheat varieties is very unfavourable to process into bread and noodle. The main problem is that the protein content of the winter wheat is very low. In most of the area, traditional spring wheat has been replaced by high-yielding winter wheat cultivars. Durum wheat was also introduced to Tibet. New oat varieties were also introduced in recent years. Trials to compare wheat, introduced oat and durum wheat were then conducted. They were also aimed at improving the wheat grain quality through cross-breeding and mixing the grain into wheat grain so that the overall protein content would be increased. This attempt may not be ideal but the protein content in oat seed and durum wheat seed tend to be much higher than that of winter wheat. Meanwhile, direct use of oats for food and fodder and durum wheat for noodle in Tibet was also set as one of the objectives.

5.2.1. Yield performances

Table 4 shows the main results of the trials of 3 oat varieties, 5 durum wheat and 2 high-yielding spring wheat cultivars. Yields of all cultivars range from 101.07 – 236.57 kg/mu. Among all the varieties of the three different crops, oat variety No. 2 yielded 236.7 kg/mu, which was the highest among all varieties tested and it was 78.5% higher than the yield of spring wheat variety – Zangchun No. 6 and 18.9% higher than the yield of Rinong No. 23. The yield of oat variety No 1 was 234.33 kg/mu that was 76.6% and 17.8% higher than Zangchun No. 6 and Rinong No 23, respectively. Among the durum wheat varieties No. 291, No. 281, No. 294 and No. 266 produced 7 – 39% higher yield than the wheat variety Zangchun No 6, but somewhat lower yields than Rinong No 23.

Analysis of variance on yields of these varieties was done. This indicated that there is no apparent variance among the replicates, but there are large variances among different varieties. T-test at 0.05 level and 0.01 level showed that the differentiation of the yield among different crops and different varieties are large. Particularly the yield of oat variety No. 2 and No.1 are significantly higher that most of the varieties of common wheat and durum wheat at 0.05 level. Tables 5 and 6 show the results of the analysis of variance of yields and t-test of significance of variation among the yields.

Table 4 - Yield of Common Wheat, Durum Wheat and Oat in three replicated treatments

Treatments
Varieties

I

II

III

Tt

x t

Durum Wheat 281

144.95

146.6

186.6

478.15

159.38

Rinong No. 23 (Wheat)

219.9

173.25

203.6

596.75

198.92

No. 3 (Naked Oat)

146.6

94.95

61.65

303.2

101.07

Durum Wheat 291

209.8

183.9

159.95

553.75

184.58

No. 1 (Naked Oat)

236.55

266.55

199.9

703

234.33

Durum Wheat 266

173.25

144.95

107.95

426.15

142.05

No. 2 (Naked Oat)

203.25

266.55

239.9

709.7

236.57

Zangchun No. 6 (Wheat)

116.6

134.95

146.6

398.15

132.72

Durum Wheat 290

113.3

119.95

106.6

339.85

113.28

Durum Wheat 294

59.95

240.65

125.65

426.25

142.08

Treatments

1624.25

1772.3

1538.4

4934.95(T)

 

X5

162.43

177.23

153.84

 

164.5(x)

 

Table 5 - Analysis of Variance based on the yield result in Table 4.

Variation source

DF

SS

MS

F

F0.01

F0.01

treatments

varieties

Error margin

2

9

18

2799.94

61043.85

28017.24

1399.97

6782.65

1556.51

0.899

4.36

3.55

2.46

6.01

3.60

Total variation

29

91861.03

       

Table 6 - T-test at 0.05 and 0.01 level for the result in the Table 5

Variety

Average Yield ( kg)

0.05

0.01

2

1

ck2

291

281

274

266

ck1

290

3

236.57

234.33

198.92

184.58

159.38

142.08

142.03

132.72

113.28

101.01

a

a

ab

ab

bc

c

c

c

c

c

A

A

AB

AB

AB

AB

AB

AB

BC

C

5.2.3. Agronomic characteristics

5.2.3.1. Growing period

All the varieties were sown on April 20th, most of the varieties matured within 135-150 days. The shortest growing period was the Oat No.2 which was 132 and the common wheat variety-Zangchun No. 6 took longest to mature, it was about 150 days.

5.2.3.2. Straw height

The height of the straw of all varieties tested ranged from 68-194.9 cm. Oat No. 3 was the tallest and the durum wheat No 266 was the shortest. Other varieties ranged from 72-190.2 cm.

5.2.3.3. Length of the spike

The length of the spike of oat varieties ranged from 20.7 – 25.4 cm. The length of the spike of durum wheat ranged from 5.77 – 7.05 cm.

5.2.3.4. Number of kernels in each spike

The number of kernels in each spike of the oat varieties ranges from 42 - 97.8. The number of kernels in each spike of durum wheat ranged from 37.4 - 65.4.

5.2.3.5. 1000 kernel weight

The 1000 kernel weight of oat ranged from 21.9 - 20.9 g. The 1000 kernel weight of durum wheat ranged from 28.6 - 44.4g

5.2.4. Potential of oat as fodder and food crop as compared with common wheat and durum wheat

The experimental tests were conducted during 1999 and 2000. Comparing the result of tests in 1999 and in 2000 all varieties were sown later to test the suitability of sowing date of these varieties. The above experiment has shown that the general agronomic characteristics of oat are better than durum wheat. The average yield of all cultivars of oat is higher than durum wheat. According to this experiment we can conclude that the adaptability of oats is better than durum wheat. An exception was that the No. 3 oat variety had serious lodging at a later stage that caused a reduction in the yield. Oat varieties No. 1 and No.2 performed very well in terms of yield and agronomic characteristics and they are suitable for Tibetan conditions for fodder and food production. Durum wheat needs good soil moisture content. When the temperature is high in spring and there is a reduction in soil moisture content, it affects the yield of durum wheat and common wheat. The yield of both durum wheat and common wheat is reduced when there is a severe drought in springtime. This is mainly because the low soil moisture content reduces the rate of germination of wheat and eventually reduces the yield. But this normally does not affect oats. The yield of oats in different years remains as normal no matter how dry it was in the springtime. This means these varieties of oats have a higher resistance to drought than wheat. Tibet is often very dry in the springtime and if there is no irrigation, there will be a major failure in crop yield due to the spring drought. In this case, wherever there is no irrigation, oats can be a potential crop to grow for food or fodder purposes. However, there is little understanding of the crop oats at the moment. It has been locally known as wild weed and little attempt had been made to promote this crop for fodder and food. Two years of experiments on testing different kinds of cultivated oat varieties introduced from outside Tibet have shown that there is a great potential for oats to be a highly adapted fodder and food crop if it is properly processed into food items for the market.

6. Utilization of oat genetic resources in Tibet

The unique biodiversity of the oat crop and natural conditions in Tibet provide a great opportunity to promote oats both as a fodder and food crop in Tibet.

6.1. Oats as a fodder crop

Farmers often harvest wild oats growing in the fields of barley and wheat at different stages. Farmers in most of the areas can easily recognize the young oat plants among the barley and wheat crop. Fresh plants of oats are directly fed to the animals. They are also dried and stored for feed sources during the winter time. In most cases, the oat plants are harvested before maturing so that the oat seed will not fall into the field. This is not only for weeding purposes, but also for collecting feed for livestock. Dried oat straw is considered as high quality feed for livestock. In many case, farmers use the collected wild oat plants from the barley or wheat fields for animals like horses and milking cows. However, oats have has not been widely planted on a large scale for fodder for animals. The main reason is that the farmer cannot collect enough seed from the wild oats for cultivation for next year. In addition, they think that wild oat is a weed and they do not think it can be cultivated for feed. They know that it is a good feed source and keep collecting from the other crops.

In recent years, scientists and agronomists have tried to test new cultivated oat varieties introduced from other provinces of China. Some of them have selected suitable varieties for local conditions. Selected varieties were planted at different altitude ranges. For example, oat was grown in Naqu prefecture and Damshong county of Lhasa. At elevations lower than 4700m, oat can grow very well for fodder. Because of its high drought resistance and adaptability to harsh conditions, the oat crop shows its great potential as a fodder crop for higher altitudes under the pastoral and agro-pastoral system. One of the main constraints in developing livestock in pastoral areas of Tibet is the shortage of feed during the winter time. Those counties that have the practice of growing oats as a fodder crop at high elevations have experienced that oats are a very promising fodder crop for feed production. In locations where large areas of cultivated land are available, but irrigation is lacking, oats as an alternative crop for feed production has been recognized by many farmers and agricultural developers. In Naidong County of Shannan Prefecture, large areas of fodder oats introduced from Qinghai provice were grown during 1996-1998. The aim was to produce feed for livestock production in the upper region where severe feed shortages occur during the winter time. In that county, oats were planted during the summer time and harvested in autumn and then processed into silage or chopped into fine pieces that were then used for feed for animals in the upper region during the winter season.

In recent years, the government has focused on developing livestock in the crop-dominated area in central Tibet. However, lack of suitable feed crops and poor feed processing restrict further development of livestock in these regions. Barley straw is the main source of feed for animals in many counties during the winter time, but the quality of the barley straw for animal feed is very poor. Livestock production in many counties has been restricted by the shortage of feed during the dry season. However, Tibet has a vast land area; there is scope for feed production. In order to boost livestock production in Tibet, both government and researchers are looking for possibilities for promoting new feed crops. The introduction and testing of new fodder crops such as oats and corn is underway. Fodder oats will be promoted in some regions. But appropriate varieties adapted to the local conditions are a precondition for promoting the oat crop as fodder.

Another concern of the local government is to develop livestock in pastoral areas. Overgrazing due to the low carrying capacity of the rangelands in Tibet and increase in the population of livestock is occurring. One of the main approaches taken by the local government has been to promote adaptive and high-yielding fodder crops for the region. Oats, in this sense, has the great advantage of wide adaptation and cold resistance in the cold climate conditions in the high altitude areas of Tibet.

Transformation of agricultural development from a subsistence farming system to a market oriented system is underway. The major policy is to restructure the agricultural production system. The purely grain production based agricultural development pattern is changing into a combination of cash crop, grain crop and fodder crop. Oats will be promoted as one of the potential crops for high quality fodder in a wider range of areas wherever it is adapted. Selection of good varieties is essential. The experiments described above suggest that good varieties can be selected for most of the areas of Tibet through the introduction of new varieties from outside Tibet.

6.2. Oat as food crop

Traditionally oats was a food crop in eastern Tibet, but this is no longer the case. With high yield and good adaptability to the local conditions, oats have a potential to be an important food crop in Tibet as well. Beta-glucan content in oat grain provides an opportunity for promoting oats as a food crop, particularly as a healthy food crop. Local people may not consume oats as food, but they can be processed into healthy food for the inner-lands of China. Our experiments during 1999-2000 showed that oats are a well-adapted and high yielding food crop if we select the right varieties and provide proper management.