A selection strategy-securing yield gains in groundnut

Abstract

The F₂ generation of six crosses with divergent parents were studied for a number of physiological and yield components in ground (Arachis hypogaea L.). A stepwise multiple regression analysis indicated the importance of photosynthetic area and leaf dry matter in explaining the variation in kernel yield. 428 F₂ plants studied for those characters in addition to pod yield and its components formed Experiment I and 1259 F₂ plants studied only for yield and its components Experiment II. The number of selection as well as pod yield gains were larger in F₃ derived from Experiment I than from Experiment II. This trend was consistent in F₄ too. The F₂ plants were also ranked on the regression index values and the F₂ ranked distribution was partitioned into 5 strata, L₁ to L₅, each containing equal number of F₂ plants. Lines derived from L₁ to L₂ accounted for large proportion of realized gains from F₃ to F₅. The results taken across experiments suggested that an efficient cost-, time-and resource-efficient strategy would be to select F₂ plants on a regression index based on yield and key physiological components like photosynthetic area and harvest index and to forward the progeny of F₂ plants from the top 25% ranked distribution.