Studies And Utilization On High-Quality Wild Grass Germplasm Resources In Tibet

There are many valuable genes contained in wild grasses, which growing in conditions of high altitude, strong ultraviolet, cold and drought climate, in Tibet high plateau, in the southwestern of China. Both in science and industry in Tibet, it is important for improving ecological environment, founding pasture and increasing grassland productivity to develop the germplasm resources.This study is conducted in Damxung County, north in Tibet, a typical alpine meadow, which is above the average altitude of 4200m. The dominant species wild forage grasses, K. pygmaea and Kobresia littledalei were observed and studied both in wild field and lab relating to their germplasm resources. In the meantime, 3 samples of Elymus nutans, which are pick up from 3 different Counties in Nagqu district in Tibet, were studied with seedling-forming model through orthogonal experiment designs. The main conclusions as following:(1) K. pygmaea germplasm resourcesIn Damxung alpine meadow, of alpine K. pygmaea, the crude protein occupies 19.92%r and the crude fiber content is 18.09% in its seed set stage, which is much higher than that of Medicago ruthenica of Legume herbage. Therefore, it is a excellent herbage in Tibet. Its maximum forage yield is 4254.62 kg/hm2 in September, which is matched to grazing and fatten the domestic animal in summer and autumn.K. .pygmaea reproduction way takes vegetative reproduction primarily, the sexual reproduction as auxiliary. Its main root length is 5 to 15cm, the rhizome is located under the soil surface 4 to 10cm, thicken 1~3mm. K. pygmaea tillering 1-10 in a year, mostly 3. The seed yield is 22.38 kg/hm2, 1000-grain weighted 0.6127g. The germination ratio is 0 when stored for three months after seed harvest, but it can reach 14% treating the seed with NaOH solution (5%) for 3 hours before germination.(2) Kobresia littledalei germplasm resourcesIn alpine wetland meadow in Damxung county, Kobresia littledalei growing period is from early May to early October, and has a plenty of leaf for the stem/leaf ratio is low in July, with a fresh forage productivity at 16864.04 kg/hm2 in August. It is a good herbage to make hay for winter and spring feeding.K. pygmaea reproduction way takes vegetative reproduction primarily, the sexual reproduction as auxiliary. Rhizome thick 0.2~0.5cm,the rhizome is apart from under the surface in the 20~30 cm soil layer, seedlings grown on the rhizome. The seed yield is 15.32 kg/hm2, 1000-grain weighted 0.5390. The germination rate is 62% when stored in three months after harvest.(3) Elymus nutans seedling testThe seedling-forming experiment of Elymus nutans, which cultivated in Qushui county in Lasa from Nagqu area, showed that Seedlings of them to be good, it could use in the production practice directly. The biomass of Elymus nutans can show the rate of seedling more accurately. Among all the factors of the seedling-forming model, the number of stems from the seedling stage have the smallest affection on the seedling survival, Early emergence of seedling do not determine the final number of seedling rate levels; the growth rate was significantly influence the survival rate in this model and it has the largest negative influence. So, in practice, control seedling growth rate of seedlings can improve the survival rate.