The ecological plasticity of the quantitative characters for ear heads of Leymus chinensis population in natural meadow in northeast China
东北草原羊草种群单穗数量性状的生态可塑性

As a perennial forage, leymus chinensis (Trin.)Tzvel has a high potential in vegetative propagation,but low earring and fruiting rates in the natural conditions.This experiment was conducted on the three fixed plots in the natural meadow for the successive 12 years.The samples of 100 ear heads were taken at random in these plots.The ecological plasticity of the quantitative characters for L.chinensis ear heads,and its correlation to climatic factors in different growing and developing stages were analyzed statistically.The results showed that there were obviously significant variations in the length of ear heads,number of spikelets and florets of the population within plot and among plots,and within year and among years respectively.For the length of ear heads,number of spikelets and florets of L.chinensis there were larger variations within year than those among years,and in each plot than those among plots,and in plots than those among years.The quantitative characters of the ear heads were correlated to growing and developing stages,especial for the sunshine duration,accumulated temperatue and rainfall during these stages to some extent.During growing and developing stages for the winter tillers,the more rainfall and less sunshine time and lower accumulated temperature were of much benefit to yong ear differentiating growing next year,and the less rainfall and more sunshine duration and higher accumulated temperature were contrary.From jointing to earring stages,the young ear differentiation favored the more rainfall.However,from greening to earring stages,it was unfavorable for the higher accumulated temperature and more sunshine duration,and also for the more rainfall in early greening stages.With the effect of climatic factors the ecological time lap resulting in the differentiation of young ear heads of L.chinensis population was even 10 months.