棉花耐盐性的双列杂交分析

A Diallel Analysis of Salt Tolerance in Upland Cotton

根据Ｈａｙｍａｎ的方法，对６个耐盐性不同的棉花品种（系）及其１５个半双列杂交组合的Ｆ１、Ｆ２ 代的平均盐害级别进行了双列杂交分析，结果表明，耐盐和盐敏感品种的一般配合力效应差异达极显 著水平，耐盐×盐敏感组合的特殊配合力普遍低于盐敏感×盐敏感、耐盐×耐盐组合。因此，棉花耐 盐育种以配制耐盐×盐敏感组合为最佳。棉花耐盐遗传参数估计说明，棉花的耐盐性存在着加性和显 性效应，以加性效应为主，耐盐性呈不完全显性，受一对主效基因控制。Ｆ１和Ｆ２代的广义遗传力接 近，Ｆ２代的狭义遗传力高于Ｆ１代，且狭义遗传力较高。因而，在Ｆ２代选择改良棉花的耐盐性是可能 的。

The 3 salt tolerance varieties and 3 salt sensitivity varieties were used as parents to generate F1. F2 form a half diallel cross. It was employed to investigate the inheritance of salt tolerance by using Hayman's diallel cross analysis. The results suggested that the general combining ability (GCA) was highly significant difference between salt tolerance and salt sensitive varieties. The specific combining ability (SCA) of R× S crosses were significantly lower than those of S × S crosses or R × R crosses. It was suggested that R × S cross were more suitable for salt tolerance breeding. Estimate of genetic parameters for salt tolerance showed that both additive and dominant effects appeared to be important for the expression of variation under salt stress, but the effect of gene with additive properties was more pronounced. The salt tolerance was determined by one incomplete dominant gene. Broad heritability of F1, generation was as much as that of F2, but sense heritability of F2 was higher than that of F1. Estimates of hN for salt tolerance were higher; suggesting that rapid improvement in salinity tolerance is possible using high selection pressures in F2 population.