我国野生披碱草属牧草居群的穗部形态多样性研究

摘要

对采集自我国12个不同分布区的105个野生披碱草属(Elymus)牧草居群的14项穗部形态指标进行研究,结果表明,我国披碱草属牧草种质资源穗部遗传多样性丰富,居群内多样性指数(H’)在0.784～1.652,平均多样性指数为1.396;居群总平均多样性指数为1.936,居群间表型分化系数为27.89％.14项穗部形态性状在居群内多样性、居群总多样性以及变异系数变化不完全一致,居群内H’最高的为旗叶与穗基部长度(1.648),居群总H'最高的为小穗长(2.054),变异系数最大的为第一颖芒长(58.932％),平均变异系数为31.22％,表明穗部形态性状均存在较大的变异,F检验差异极显著.引起居群形态差异的性状与种子产量密切相关,主要包括穗长、穗宽、第一颖芒长、第一外稃长、第一内稃长、第一外稃芒长、每穗轴小花数、第一颖长和第一颖宽.我国野生披碱草属牧草的多样性和分布格局是相关的,我国西北部是野生披碱草属牧草分布中心,也是披碱草属牧草的多样性中心.此外,提出了我国披碱草属牧草保护的策略.%105 wild Elymus spp. Populations in 12 different distributions of China were collected and analyzed on 14 ear morphological characters. The results showed that it existed abundant genetic diversity in ear morphological characters of Elymus spp. In China. The diversity index within each population was from 0.784 to 1.652, and its average was 1.396. The total average diversity index among populations was 1.936 and the phenotypic differentiation coefficient was 27.89%. The 14 ear morphological characters were not exactly similar in diversity index within and among populations, and variation coefficient. The higest diversity index within populations was the length between boot leaf and ear, which was 1.648, While the highest total index among populations was spikelet length, which was 2.054. The highest variation coefficient was awn length of the first glume, which was 58.932%, and the average variation coefficient was 31.22%. It showed that the ear morphological characters had a large variation, and F-test were significant difference. The traits which reduced morphological differences were closely related to seed yield, it mainly included ear length, ear width, awn length of the first glume, the first lemma length, the first palea length, the first lemma awn length, flowers per rachis, the first glume length, the first glume width. The genetic diversity of wild Elymus spp. Was related to its distribution patterns in China, and Northwest China was the distribution center as well as diversity center of wild Elymus spp.. Some conservation strategies were also proposed.