Study On Biological Characteristics And Seed Yield Of Elymus Nutans Collected From Different Elevations

Elymus nutans is a kind of important forage in northwest and north of China, which has strong stress resistance and high grass yield with a main distribution in elevation2500-4000m. Seeds of E. nutans were collected in four different elevations(2500m、3000m、3500m、4000m)in Gannan.The seedlings were transplanted to experiment station of Lanzhou University in Yuzhong campus after cultured in greenhouse.Biological characteristics and seed yield was evaluated for two years after the seeds collected were planted in the same habitat.The seeds harvested in the first year were sowed to evaluate the agronomic traits further. The expected results aim to provide theory and data support for breeding and further study of germplasm resources.The main results were as follows:1. The planted E.nutans cultured from the seeds collected from different elevation of Gannnan showed different applicability in the same habitat of Loess Plateau.The germplasm from4000m had the weakest adapt ability,while seed yield per plant was lower than the others especially with the years of growth.The growth period of germplasm in4000m was7days earlier than the others, as the other three were close.2. In the same planting habitat,individual variation analysis within population showed that a larger variation degree were characterized by seed yield per plant(38.51%),dry weight per plant(48.49%)and fertile tiller per plant(60.69%).The following variations were the thousand seed weight(26.82%),spikelet number per fertile tiller(14.62%)and seed number per spikelet(16.25%)respectively.3. Individual seed yield and its components of correlation analysis among different populations from different elevation showed that there was a significant coefficient between individual seed yield and individual dry weight in the2years, which was0.867and0.715respectively(p=0.01),which followed by components of correlation of fertile tiller per plant(r=0.627、0.634, p=0.01) and then the seeds number per spikelet(r=0.356,0.272, p=0.01).4.The population of E.nutans from3500m and3000m had better performances than that from4000m and2500m in biomass, tiller number, leaf number and seed yield per plant, through analyses of2years performance of populations from different elevation and1year reseeding of the harvested seeds(P<0.05).