小麦穗部性状的配合力和遗传力分析

ANALYSIS ON THE COMBINING ABILITY AND HERITABILITY OF THE SPIKE CHARACTERS IN WHEAT

利用Griffing完全双列杂交方法II,对冬小麦 8个亲本的主穗长、结实小穗数、不孕小穗数、主穗粒数、小穗粒数、每穗粒数、千粒重和单穗粒重 8个穗部性状的配合力、基因效应和遗传组成进行了研究。结果表明 :不孕小穗数的遗传主要受加性基因效应作用 ,其余 7个性状的遗传受加性基因和非加性基因共同作用 ,但加性效应更加重要。环境对穗部性状的遗传影响较小 ,狭义遗传力除单穗粒重较低外 ,其余 7个性状均较高 ,早代选择有效。宁麦 9号穗部性状的一般配合力最好 ,宁麦 8号和扬麦 9号可作为改良穗粒数的骨干亲本 ,而扬麦15 8可作为产量育种的适应性亲本。宁麦 8号×郑 90 2 3、宁麦 9号×郑 90 2 3和扬麦 9号×高优 5 0 3三个杂交组合的特殊配合力效应值在穗部 7个性状上均表现正向效应 ,可作为高产育种的重点组合。

The combining ability, gene effect and genetic composition were studied for the length of main spike, fertile spikelets, sterile spikelets, kernels of main spike, kernels of spikelet, kernes per spike, 1000-grain weight and kernel weight per spike of 8 wheat cultivars by Griffing's complete diallel crossing model II. The results indicated that the inheritance of sterile spikelets was mainly controlled by additive genes, and both additive and nonadditive gene effects did exist in the inheritance of other seven spike characters, but the additive effect was predominant. The genetic effect of environment on the spike characters was not significant, and the narrow heritability of spike characters was rather higher except that of kernel weight per spike. So the early-generation selection was effective. Among the eight parents the general combining ability of spike characters of Ningmai No. 9 was the best. Ningmai No. 8 and Yangmai No. 9 could be used as the core parents to improve the kernel number of spike, and Yangmai 158 as an adaptation parent in the breeding for yield potential. The relative values of specific combining ability of seven spike traits in the three crosses involving Ningmai No. 8×Zheng 9023 ,Ningmai No. 9×Zheng 9023 and Yangmai No. 9×Gaoyou 503 were all positive, and they could be considered as the key cross combinations in a high-yield breeding.