Abstract: As a major germplasm resource of the Tibetan Plateau region,plant species of Elymus spp. play a central role in the improvement of alpine grassland because of its high ecologically adaptation. To study the differences in seed yield between branched and unbranched inflorescences and the relationship between inflorescence branching traits and seed yield in the Elymus spp.,the present study analyzed and compared the seed yield of inflorescences with and without branches. At the same time,correlation analysis,principal component analysis,and pathway analysis of inflorescence branching traits with seed yield were also carried out,using 75 Elymus spp. germplasm resources from different regions of the Qinghai-Tibetan Plateau as experimental materials. The results showed that the seed yield of branched ones was significantly higher than those of inflorescences unbranched (P<0.05);branching spike seed weight,total inflorescence weight,number of branching seeds,and number of spikelets were closely related to seed yield with correlation coefficients of 0.94,0.99,0.71 and 0.86,respectively. The experimental results showed that branching spike seed weight could be increased by increasing total inflorescence weight,number of branching seeds,and number of spindle seeds,which in turn significantly increased seed yield. Inflorescence branching traits have a strong influence on seed yield,which may provide assistance in screening and utilizing forage germplasm resources in Elymus spp. and the breeding of wheat tribes.

Key words: Elymus, Inflorescence branching, Seed yield

摘要： 披碱草属牧草生态适应性强,是青藏高原地区草地质量改善的主要种质资源。为探究披碱草属花序分支与未分支花序的种子产量差异及花序分支性状与种子产量的关系,本研究以来自青藏高原不同地区的75份披碱草属种质资源为试验材料,分析比较了发生分支和未发生分支的花序种子产量,同时对花序分支性状与种子产量进行相关性分析、主成分分析和通径分析。结果发现:花序分支种子产量均显著高于花序未发生分支的种子产量(P<0.05);分支穗种子重、总花序重、分支穗种子数、小穗数与种子产量关系密切,相关系数分别为:0.94,0.99,0.71和0.86。试验结果表明,在生产中可通过增加总花序重、分支穗种子数、主轴种子数来增加分支穗种子重,进而显著提高种子产量。披碱草属花序分支性状对种子产量影响较大,可为披碱草属牧草种质资源筛选利用和小麦族的育种提供帮助。

关键词: 披碱草属, 花序分支, 种子产量