我国几个陆地棉品种枯萎病抗性的遗传分析

Inheritance of Resistance to Fusarium Wilt in Several Chinese Upland Cotton Varieties

根据Hayman(1958)方法对4个抗病品种和4个感病品种共8个亲本及其8个半双列杂交组合的F_2代的平均病级进行双列杂交分析,结果表明.棉花对枯萎病的抗性存在加性和显性效应,无上位性,以加性效应为主;抗性呈不完全显性,受一对基因控制,广义、狭义遗传力都高达90％以上。16个抗×感组合的F_2代抗、感植株出现3:1比例分离,亦证实抗性受一对基因控制。抗、感病品种一般配合力差异达极显著水平,抗×感组合特殊配合力普遍低于感×感,抗×抗组合.因而抗病育种以配制抗×感类型组合为佳。

Hayman's diallel crosses analysis (1958) was employed to investigate the inheritance of upland cotton resistance to Fusarium wilt. 4 resistant varieties (R) and 4 susceptible varieties (S) were used as parents to generate F1 and F2 half diallel crosses. 8 parents and 28 F2 crosses were planted in randomized complete block experiment with 3 replications in heavily infected field. The result suggested that epistatic effect was insignificant while additive and dominant effects were significant, and additive effect was more important than dominant effect. The resistance was determined by one partial dominance gene. Broad and narrow sense heritability estimates were 0. 93 and 0. 92 respectively. The ratio of resistant plants to susceptible ones in F2 generation of 16 R×S crosses was 3 : 1. The general combining abilities of the 4 resistant varieties were significantly lower than those of the 4 susceptible ones. It was suggested that R ×S crosses were more suitable for breeding resistant varieties.