Combining ability of main agronomic traits in four new leaf mustard sterile lines

【Objective】 The combining ability of main agronomic traits of leaf mustard was studied in order to provide theoretical basis for accelerating the application of newly selected sterile lines of leaf mustard and the breeding of strong dominant hybrid combination.【Method】 Four sterile lines Meikuan A，Taikuan A，Dajie A and Mingchang A were as female parents and three inbred lines V0331，V0332 and V0333 were as male parents，incomplete diallel cross design was used to group twelve hybrid combinations. The variance analysis of combining ability for 11 agronomic traits was carried out， and the contribution rate of genotype variance and heritability were estimated.【Result】 There were real genetic differences among the cross combinations of leaf mustard， the variances of general combining ability of 11 main agronomic traits of sterile lines and inbred lines reached significant（P<0.05）or extremely significant（P<0.01， the same below）levels. The variance of special combining ability（SCA） of hybrid combinations was extremely significant except plant width. Through the analysis of the relative effect of combining ability，the male sterile line Taikuan A，Mingchanga A and inbred line V0331 were selected as excellent parents. The combination of three advantages，Meikuan A×V0333，Mingchang A× V0333 and Taiwan A×V0331，was selected. In the case of the male parent was broad-stem mustard type， the phenotypes of plant height，plant width，leaf length，petiole length，petiole width，middle rib width and leaf number of leaf mustard hybrids were mainly determined by the inheritance of mustard male sterile lines. Leaf width，petiole thickness，middle rib thickness and yield per plant were mainly affected by male parent inbred lines. The general heritability of 11 main agronomic traits was more than 70.00%. The narrow sense heritability of 9 traits，namely，petiole length，middle rib width， leaf length，mid-leaf number，petiole width，yield per plant，middle rib thickness，plant width and petiole thickness，was more than 55.00%，the additive genetic effect was large，and the breeding could be selected in the lower generation. The narrow sense heritability of plant height and leaf width were 27.41% and 35.74%，respectively. The two traits were greatly influenced by environment and the interaction between parents，breeding was suitable for high generation selection.【Conclusion】 Taikuan A and Mingchang A are ideal parents of sterile lines，which can be used by expanding the combination. Meikuan A×V0333，Mingchang A×V0333 and Taikuan A×V0331 are the dominant combinations，they have utilization values， it is suggested that further regional test should be carried out.