大麦农艺性状和子粒支链淀粉的多元分析与评价

为了解高支链淀粉大麦种质资源的表型特性,以16份高支链淀粉含量的大麦种质资源为材料,通过主成分分析和聚类分析研究了9个主要农艺性状的遗传多样性。结果表明,9个农艺性状中芒长的变异系数最大,为43.26%,单穗粒数次之,子粒粒宽的变异系数最小,为4.76%。主成分分析结果表明,前3个主成分累计贡献率为78.844%,可依次归类为子粒大小控制因子、穗粒数控制因子和株型控制因子。相关性分析结果显示,支链淀粉含量与株高呈极显著负相关。采用类平均法聚类将参试的16份大麦种质资源分为4个大类,第一、二类属于矮秆低产型;第三类的千粒重和芒均最长,可以作为以千粒重为选拔对象的亲本;第四类属于高秆型。为了改良糯大麦种质甘垦5号和C2-1的农艺性状可从第四类材料中选择优异亲本。结合主成分分析和聚类分析,能较好地对参试种质资源主要农艺性状做出综合评价,为高支链淀粉大麦遗传育种提供优良的种质资源,为合理选配亲本提供参考。

Multivariate Analysis and Evaluation on Agronomic Traits and Grain Amylopectin Content of Barley

To discover the phenotype characteristics of higher-amylopectin barley, nine agronomic traits of 16 higher-amylopectin barley genotypes had been investigated for genetic diversity, which based on principal components and cluster analysis. The results indicated that the coefficient variation of awn length (43.26%) was the highest, followed by the number of kernels per spike, and the coefficient of variation of grain width (4.76%) was the lowest among nine agronomic traits. The principal component analysis showed that accumulation indices of 78.844% from the top three principal components, which were grain size factor, kernels per spike factor, and plant type factor. Correlation analyses indicated that there was significant negative correlation between plant height and amylopectin content. Cluster analysis classified all tested materials into 4 categories. The group Ⅰ and Ⅱ had traits of dwarf and low yield. The group Ⅲ had the highest 1000-grain weight and the longest awn length among all varieties. The group Ⅳ had high stalk. In order to improve agronomic traits of waxy barley (Ganken 5 and C2-1), high-quality parents should be selected from the group Ⅳ. In conclusion, principal component analysis and cluster analysis could make a comprehensive evaluation on main agronomic traits in barley, which could provide better germplasm resources for the parents selection for breeding new barley cultivars with higher-amylopectin.