Vegetative Propagation and Reproductive Growth of Two Ecotypes Leymus chinensis L. in Songnen Plain

Systems of both vegetative propagation and characteristics of sexual reproduction in two ecotypes Leymus chinensis were studied under sandy soil and salt-alkali soil habitats in Songnen plain using observation in experimental plots and sampling in naturally-meadows.Propagation strategy and adaptation regulation of Leymus chinensis populations were investigated to understand the basics of grazing production.The quantity of vegetative propagation in two ecotypes of Leymus chinensis followed an increasing rule of power function y=axb(b represented a speed of population vegetative propagation).The coefficients of determination had significant differences.The speed-of-population vegetative propagation for two ecotypes of L.chinensis under salt-alkali soil habitat was higher than that under sandy soil habitat.The speed-of-population vegetative propagation for yellow-green ecotypes of L.chinensis was higher than that for grey-green ecotypes under either salt-alkali soil habitat or sandy soil habitat.Reproduction allocationⅠ,length of spike,percentage of reproduction growth and their variation coefficients for two ecotypes were higher under salt-alkali soil habitat than those under sandy soil habitat.There was a significant negative correlation between reproduction allocationⅠ and the percentages of vegetative organ weight.Therefore,habitat had effects on characteristics of sexual reproduction for two ecotypes of L.chinensis and there was negative correlation between sexual reproduction and vegetative growth.