Abstract:

Evaluation of genetic diversity could benefit the identification of optimal parental combinations for obtaining segregating offspring with maximum genetic variability, and facilitate the introgression of favorable genes from various germplasm into commercial cultivars. In this study, Avena sativa L. collections including 45 Chinese and international accessions were analyzed through phenotypic analysis of 20 agronomic traits, and provided the basis for promoting the breeding of forage oat varieties. Main conclusions were as follows:there were significant differences in the phenotypic traits diversity of the tested materials, all of the phenotypic traits showed abundant variation, and the genetic basis was broad. The genetic diversity of the grain weight of main spike was the highest (3.86), and the co-efficient of variation of grain number per plant was up to 36.98%. There were different degrees of correlation among the phenotypic traits of the tested materials. The principal component analysis transformed 10 traits into four principal components that represented 83.735% of the original index, and constructed a quantitative evaluation function model with four principal component factors as parameters. The results of two-dimensional analysis showed that Z4 (Qingyin 1), Z5 (Bauntebue), Z6 (Dingyan 2), Z7 (Dingyin 1), Z12 (Jerry), Z21 (Marion), Z22 (Trophy) and Z32 (Loevile) were the best materials of factor coordination, and the comprehensive performance was excellent. According to the geographical origin and phenotypic traits of Avena sativa L. germplasm, they were clustered into three groups:group Ⅰ and Ⅲ could be used as a good parents for breeding high yield, disease resistance and antifreeze varieties, and group Ⅱ including the abundant geographical origin could be used as breeding target character of the excellent parents.

Key words: Semi-arid area, Avena sativa L.germplasm, Phenotypic traits, Genetic diversity, Comprehensive evaluation

摘要：

通过遗传种质的多样性评估，可以指导育种中优异互补亲本的选择，进而提高优异基因的积累叠加和新品种培育的效率，为促进饲用燕麦品种选育提供基础依据。本研究选用45份来自国内外的饲用燕麦种质，通过对20个表型性状的遗传多样性分析，结合二维排序综合评价优异种质资源，结果表明：供试种质材料表型性状遗传多样性丰富，遗传基础广泛；单株粒重的遗传多样性指数（3.86）最高，单株粒数变异系数高达36.98%，所有表型性状均表现出了丰富的变异；主成分分析将10个表型性状转化成可以代表原有指标83.735%信息量的4个主成分，构建出以4个主成分因子为参数的定量评价函数模型，并通过二维排序筛选出Z4（青引1号）、Z5（Bauntebue）、Z6（定燕2号）、Z7（定引1号）、Z12（Jerry）、Z21（Marion）、Z22（Trophy）、Z32（Loevile）等8个因子协调最好的优异种质材料；系统聚类将供试种质划分为3大类群，第Ⅰ、Ⅲ类群可作为选育高产、抗病、抗倒品种的优良亲本，第Ⅱ类群包涵种质地理来源丰富，可作为选育多目标性状的优良亲本。

关键词: 半干旱区, 饲用燕麦种质, 表型性状, 遗传多样性, 综合评价