Abstract: Grain size determines grain vigor and yield and is an important reference for selecting breeding materials. In this study， 202 Avena sativa germplasm resources from different sources were selected to determine the morphological indices of traits associated spike characteristics and grain size， to comprehensively evaluate the trait characteristics of the test materials， and to establish a basis for selecting materials for different breeding targets. The results showed that the highest genetic diversity index of the four qualitative traits was spikelet type （0.69）； among the 20 quantitative traits， the highest genetic diversity index was the grain length/grain width （2.08）， and the highest coefficient of variation was the number of spikelets （27.17%）， grain width， thickness， and bulk were all highly significantly and positively correlated （P<0.01） with thousand grain weight. Multiple regression analysis showed that spike weight， grain side area， and bulk significantly and positively affected thousand grain weight （P<0.01）. The traits of the test materials were categorized into three main functional components： “grain development and storage factor” “grain shape and structure factor” and “spike characteristics and yield factor”. The test materials were divided into five groups， of which taxa IV and V could be used as breeding materials for heavy-spike， multi-seeded， large-grain types breeding materials， and taxa I could be used for long-spike， multi-seeded， small-grain type breeding materials.

Key words: Avena sativa, Germplasm resources, Spike characteristics, Grain size, Genetic diversity

摘要： 种子大小决定种子活力和产量，是筛选育种材料的重要参考依据。本研究选用202份不同来源的皮燕麦（Avena sativa）种质资源，测定穗部特征与种子大小性状的形态指标，综合评价供试材料的性状特征，为不同育种目标材料的选择奠定工作基础。结果表明：4个质量性状遗传多样性指数以穗型（0.69）最高；20个数量性状遗传多样性指数以长宽比（2.08）最高，其变异系数以小穗数（27.17%）最高。种子宽、厚和体积与千粒重均呈极显著正相关（P<0.01）。多元回归结果表明，穗重、种子侧面面积和体积极显著正向影响千粒重的大小（P<0.01）。供试材料的性状特征划分为“种子发育及贮藏因子”“种子形状及结构因子”和“穗部特征及产量因子”3个主要功能成分。将供试材料分为5个类群，其中类群Ⅳ，Ⅴ可作为重穗多籽大粒型育种材料，类群Ⅰ可作为长穗多籽小粒型育种材料。

关键词: 皮燕麦, 种质资源, 穗部特征, 种子大小, 遗传多样性