小麦核质互作杂交种农艺性状和籽粒性状的杂种优势分析

为探究核质互作杂交种不同性状间的遗传变异规律和杂种优势，用8种小麦同核异质、同质异核雄性不育系分别与恢复系R5174、R2726组配获得16个杂交组合，对其F₁代及亲本的11个农艺性状和6个籽粒物理性状进行遗传变异、杂种优势、相关性、主成分及聚类分析。结果表明：（1）F₁表型性状的变异系数为3.00%～32.72%，农艺性状的变异系数大于籽粒性状；（2）不同性状间杂种优势差异显著，中亲优势和超亲优势分别为0.22%～12.50%和-13.51%～3.61%，其中正中亲优势组合最低比例为50%，正超亲优势组合最高比例可达81.25%；（3）粒形与旗叶面积呈显著正相关，与穗长、小穗数、穗粒数呈显著负相关；（4）从通过主成分分析得到的F₁代综合得分看， P型和Y型细胞质背景下的AK58不育系与R2726的杂交组合F₁表现最好；（5）通过聚类分析可将F₁分为两大类，其中第二大类包含除AS细胞质背景的AK58异质不育系与恢复系R2726组配的杂交组合，其共同的特征是籽粒表面积大、千粒重高及旗叶性状较好，表型性状的综合表现优于第Ⅰ类群，说明杂交种的性状受恢复系和不育系核背景影响较大。

Heterosis Analysis on Agronomic Traits and Grain Traits of Nucleus-Cytoplasmic Hybrid Wheat

In order to explore the genetic variation and heterosis of different traits between nucleus-cytoplasmic hybrid wheat, the eight different isonuclear alloplasmic wheat male sterile lines(CMS) were respectively crossed with R5174 and R2726 to obtain a total of 16 hybrid combinations, and 11 main agronomic traits and six grain traits from F₁ generation and their parents were investigated.We analyzed genetic variation, heterosis, correlation and performed principal component and cluster analyses.The results showed that:(1) The variable coefficients between phenotype traits of F₁ varied from 3.00% to 32.72%, and coefficient of variation of agronomic traits is larger than that of grain traits;(2) There are significant differences in all of the traits of F₁ generation, with the average mid-parent heterosis ranging from 0.22% to 12.50%, and the minimum positive mid-parent heterosis of hybrid combination was 50%; while the range of over-parent heterosis was -13.51%-3.61%, and the highest positive heterosis was 81.25%;(3) Grain shape had positive significant correlation with flag leaf area, which was opposed to panicle length, spikelet number, and grain number per spike;(4) The four principal components were determined by principal component analysis, and the comprehensive evaluation indicated hybrid combinations of AK 58 and 2726 under Triticum premepius and Triticum aestivum ssp.yunnanense King cytoplasmic had excellent performance on agronomic traits and grain traits;(5) Cluster analysis showed that 16 hybrid combinations can be clustered into two groups, among which the second group includes the cross combinations of AK58 heterogenic male sterile line and restorer line R2726 with the exception of AS cytoplasmic background.Their common characteristics are large grain area, high 1 000-grain weight and better flag leaf characters.The comprehensive performance of phenotypic characters is better than that of group I, which indicates that the characters of hybrids are greatly affected by the nuclear background of restorer line and male sterile line.