Inheritance and combining ability of grain yield in half diallel barley population

Abstract

Studies on genetic control of grain yield are of great importance for devising effective breeding programmes for yield gain in barley. Hence, inheritance of grain yield, heterosis and combining ability were investigated in barley population obtained from half-diallel crossing among 7 parental lines. The analysis of variance revealed that mean squares due to genotypes were highly significant for grain yield indicating wide diversity among the parental materials used in the study. Mean squares of general combining ability (GCA) and specific combining ability (SCA), the ratio of GCA to SCA mean squares and portion of additive and dominance variances showed, importance of both additive and non-additive gene effects for grain yield. The non significant ratio of GCA to SCA mean square highlighted that non-additive gene effects were more important than additive effects. Distribution of dominant and recessive alleles in parents were asymmetrical and parents possess majority of recessive alleles. Since average degree of dominance has values greater than 1, which indicated over-dominance type of gene action in the inheritance of the grain yield. The parent BHS400 was considered suitable according to its yield capacities and general combining ability effects. Only 2 crosses viz., BHS400 X RD2660 and BHS400 X RD2552 had significant higher grain yield than that of the check variety (BHS400), high significant SCA values and high significant useful heterosis values. Considering average narrow-sense heritability and over-dominant effects in genetic control of grain yield it is better to postpone selection for this trait until advanced breeding generations.