小麦产量构成因素的基因效应和杂种优势分析

摘要

To improve the selection efficiency for yield components in wheat, the gene effects and heterosis of kernel number per spike ( KNS) and thousand-grain weight ( TGW) were studied. Seven winter wheat parents with diverse KNS and TGW were crossed by a 7×7 complete diallel crosses (Griffing’s method II). Parents and their 21 crosses were grown in a randomized complete block design experiment at two sites during 2013-2014 growing seasons. The inheritance of KNS and TGW was in agreement with the additive-dominance model, and the dominant gene effects playeda predominant role in the genetic variation of the two traits. The degree of dominance was superdominant. Alleles controlling more KNS and high-er TGW were dominant. The average narrow sense heritabilities of KNS and TGW at two locations were 54. 00% and 63. 17%, respectively. Both KNS and TGW showed positive average heterosis and heterobeltiosis, with a great range of variation, and significant differences in magnitude of the heterosis were observed among genotype, location, and genotype × location interaction.%为提高对小麦产量构成因素的选择效率，以7个半冬性小麦品种及按7×7双列杂交设计的21个F1杂交组合在2个地点的试验资料，研究了小麦2个产量构成因素—每穗粒数和千粒质量的基因效应和杂种优势。结果表明，每穗粒数和千粒质量的遗传符合加性-显性模型，基因显性效应的作用远大于其加性效应，显性程度为超显性。增效基因为显性，减效基因为隐性。每穗粒数和千粒质量在2个试点的平均狭义遗传力分别为54.00％和63.17％。每穗粒数和千粒质量表现正向的平均杂种优势和超亲优势，变异幅度较大，并在基因型、地点及基因型与地点互作间存在极显著差异。