Combining ability analysis and phenotypic correlation of nodule parameters and agronomic traits in peanut (Arachis hypogaea L.)

Abstract

Choice of parental lines is primarily important for the ultimate success of breeding programs, while correlation among traits is also useful information when simultaneous selection for multiple traits is considered. The first objective of this study was to estimate general combining ability (GCA) and specific combining ability (SCA) for fresh and dry weight of nodules, pod yield, seed yield, 100-seed weight, pod number per plant and shelling percentage in the F3 generation of 25 peanut crosses derived from 5x5 North Carolina Mating Design II to identify the best parents for these traits. The second objective was to determine correlation among these traits. The experiment was conducted under field condition at Khon Kaen University'sAgronomy Farm. The 25 crosses and their parents were arranged in a randomized complete block design with 2 replications. GCA mean squares were significant for nodule fresh weight, pod yield, seed yield, 100-seed weight, pod number per plant and shelling percentage, whereas SCA mean squares were not significant for these traits, indicating the importance of additive gene effects governing the inheritance of these traits. PI 269109 had high GCA effects for nodule fresh weight, 100-seed weight, pod number per plant and shelling percentage, and PI 243574 had good combining ability for pod yield and seed yield. KK 60-3 was identified as good general combiner for nodule fresh weight, pod yield, seed yield and 100-seed weight. High and positive phenotypic correlation was found between nodule fresh weight and nodule dry weight. Pod yield,seed yield and 100-seed weight were positively correlated with each other.

Keywords

• general combining ability
• specific combining ability
• additive gene effect