Combining ability analysis of fruit texture traits in cucumber by mechanical measurement

Abstract

Traits that contribute to fruit texture are important targets for genetic improvement in cucumber, and the knowledge of the combining abilities of parental genotypes is crucial to conducting systematic breeding of new F1 hybrid cultivars that possess a desired fruit texture. We estimated the general combining ability (GCA) and specific combining ability (SCA) of fruit texture traits related to fruit firmness and crispness. We produced a diallel set of 28 F1 hybrids by crossing eight cucumber genotypes in a half-diallel mating design. We obtained quantitative scores of fruit texture by means of mechanical measurement and analyzed them by Griffing's combining ability analysis to estimate the GCA and SCA effects of the parental genotypes. The GCA effect was of more significance than the SCA effect in determining hybrid performance. Estimates of the GCA effects were highly significant for most parental genotypes and were highly correlated with actual performance of parental genotypes. Because of this close correlation between GCA effect and actual fruit texture traits exhibited by the parents, we demonstrated that all traits could be effectively pre-selected at the level of parental genotype.