恢复措施对退化草地羊草种群有性生殖数量特征的影响

在封育和翻耙处理的退化羊草草地上，对羊草种群有性生殖的数量特征进行了比较研究．结果表明，翻耙样地羊草种群密度下降显著，生殖蘖密度变化不显著，生殖蘖穗长、节间长、生殖生长比率、穗节数、小穗数、小花数、饱满籽实数和结实率都有显著增长，籽实产量、净籽实重和千粒重分别是封育样地的2．68、3．49和1．3倍．在翻耙样地中，羊草种群发育有复小穗的生殖蘖比封育样地多16％，生殖蘖上复小穗的数量也显著增加，生殖蘖以相对少的小穗，生产了较多的小花和更多的籽实来提高种群的籽实产量．两个样地中羊草种群的生物量生殖分配在种群对生殖蘖RA1、生殖蘖对穗序RA4、穗序对籽实RA6 3个层次上无显著差异，而种群对穗序RA2、生殖蘖对籽实RA5的生殖分配差异显著，种群对籽实RA3的生殖分配差异极显著．

Effect of restorative measures on quantitative characters of reproduction for Leymus chinensis population in the degenerated grassland

Studies on the reproductive characters of Leymus chinensis population in two plots showed that the density of L.chinensis population declined significantly in plowing plot,while the density of reproductive tillers varied insignificantly.The reproductive tiller had longer ear,longer inter-node,higher ratio of reproductive growth,higher seeding percentage,more ear-nodes,more spikelets,more florets and grains in plowing plot than in enclosing plot.The grain yield,net weight of grain,and the weight of 1000 grains was 2.68 times,3.49 times and 1.3 times higher in plowing plot than in enclosing plot,respectively.The reproductive tillers with double-spikelet were 16% more in plowing plot than in enclosing plot,and they developed more double-spikelets.Relatively,the reproductive tiller in plowing plot developed few double-spikelets,more florets and more grains,so that,the grain yield of the population was enhanced largely.The reproductive allocations of L.chinensis didn't response differently to both plowing and enclosing at three module levels,including population to reproductive tiller,reproductive tiller to ear,and ear to grain,but the allocation of population to ear and to grain,and the allocation of reproductive tiller to grain were significantly higher in plowing plot than in enclosing plot.