以27个穗粒性状不同的小麦品种为材料，对小麦穗粒数形成过程中的各构成因素进行了相关、通径和聚类分析。结果表明：不同穗粒性状基因型在分化小穗数、结实小穗数、分化小花数和可孕小花数上均有明显差异。特大穗型小麦的小花分化速率最快，分化持续时间最短。穗粒数对小麦产量提高的贡献最大，穗粒数与千粒重之间不存在负相关。在穗粒数各构成因素中，分化小穗数、结实小穗数、分化小花数、可孕小花数和小花结实率与穗粒数均呈极显著正相关，其中小花结实率的作用较大，直接通径系数高达0.8225。在南京生态条件下，小花分化速率与分化小花数、可孕小花数和穗粒数呈显著正相关，但小花分化持续时间与分化小花数和穗粒数的相关均不显著。因此，小麦穗粒数的改良应在增加结实小穗数的基础上提高小花的分化速率和小花的结实率。%Kernel number per spike and its components in 27 wheat (Triticum aestivum L.) genotypes differing in kernel number per spike were studied by correlation, partial correlation and cluster analysis. The results showed significant differences in total spikelets, fertile spikelets, total florets, fertile florets per spike among various genotypes. Genotypes with more kernels per spike showed higher floret differentiation rate, shorter differentiation duration, and higher numbers of spikelets, total florets and fertile florets per spike. There was highly significant correlation between kernel number per spike and grain yield, but no negative correlation between kernel number and grain weight. The correlations were also highly significant between kernel number per spike and fertile spikelets (r=0.8185), total florets(r=0.5068), fertile florets(r=0.7676) and grain set rate(r=0.5473). The grain set rate was highly correlated to kernel number per spike with the standardized estimate as high as 0.8225. There were significant correlation between floret differentiation rate and total florets(r=0.7532), fertile florets(r=0.4367), and kernel number per spike(r=0.5730), whereas the duration of floret differentiation was not significantly related to total floret number and kernel number per spike. The results indicated that improving the kernel number per spike should be focused on increasing the spikelet number, floret differentiation rate and grain set rate.
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