Abstract:

The purpose was to study the heterosis and genetic characteristics of F1 crosses of economic traits using sterile lines in upland cotton. Three upland cotton male sterile lines and four normal parents were crossed in the way of incomplete diallel cross. Using additive-dominant genetic model, phenotypic variance, combing ability, genetic variance, and genetic correlation coefficient were analyzed upon the economic traits of 12 F1 crosses and the control. Results showed that, for economic traits, compete vigor was not obvious. Special combing ability and general combing ability of male sterile line 2 and normal parent 48784 were relatively large, which meant that this line could be used as parents in breeding. Narrow-sense heritability of boll weight per boll and lint percentage was larger than 70%, which indicated that those two traits could be selected in early generation. Narrow-sense heritability of seed cotton yield, lint yield and lint yield before frost were only above 25%, the ratio of dominant variance component to phenotypic variance arrived at the level of very significant, which indicated that those three traits should be selected in the later generations, and have the potential of vigor. The additive correlation of most traits in pairs arrived at the level of positive significant, among which, additive correlation between seed cotton yield, lint yield, and lint yield pre-frost, boll weight and lint percentage arrived at level of very significant. Sterile lines showed large potentials in cotton heterosis utilization.