Study On Seed Characteristic And Drought Resistance Of Wild Forage In Tibet

Based on the ISTA(International Seed Testing Association)seed certification regulation, seed quality of 32 seed lots from the Tibet wild forage and change of germination characteristic under different seed treatment were determined as to evaluate the seed dormancy and the value for practice; By osmotic stress of polyethylene glycol 6000(PEG-6000) and drought stress on seedling roots exposed to the open air, grouth and development and physiological reaction in 11 of them were studied to evaluate the adaptability against drought stress and the relative drought resistance in order to provide scietific basis for the reorganization,conservation and utilization of Tibet wild forage . The main results were as following:1 Experiment No. 1 Study of seed characters of 32 Tibet wild forageThe thousand-seed-weight and seed quality of 32 Tibet wild forages were normly showed low,but the germination rate of 4 wild forage were over 80%,which might be used directly in practise ; the seed g ermination rate of 8 wild forages treated by 6 methods were over 80% and of directive usage value in practise.2 Experiment No. 2 Study of osmotic stress of polyethylene glycol 6000(PEG-6000) on the germination of 11 Tibet wild forage in the Germination periodIn 11 studied materials, 5 wild forages have a high drought resistance, 4 wild forage have a middle drought resistance and 2 wild forage have a low drought resistance in bourgeon period.3 Experiment No. 3 study of drought stress on seedling roots from pot exposed to the open air of 9 Tibet wild forageGenerally drought resistance of Elymus was stranger than Poa 4 . In selected 9 materials with highest drought resistance were Elymus( Na Qu),Elymus(Dang Xiong of La Sa),Elymus(Nan Mu Lin of Ri Ka Ze) and Elymus(Lu Qiong of Shan Nan),3 with a middle drought resistance were Elymus (Nai Dong of Shan Nan),Poa annua Linn(Lang Ka Zi) and Poa annua Linn ( Nai Dong of Shan Nan) and2 with lower drought resistance were Poa annua Linn (Dang Xiong of La Sa) and Poa annua Linn(Lin Zhi) in seedling periods.4 Comprehensive evaluatin It was discovered in this study that 4 wild quality forages with higher germination percentage and 8 with a significantly increased germination percentage by different seed treatments were of practical using value; Different wild forage showed different strength and stability of drought resistance in different growth period. Poa pratensis Linn. (LangKaZi) ,Elymus(Nan Mu Lin) and Elymus(Lu Qiong) showed a high and stable drought resistance in two period and were of much more important value in the future deeping research...