Hybridisation and description of the trait-based and empirical selection programs

Abstract

The hybridization and selection programmes for drought resistance in groundnut, implemented at 4 locations in India (Tirupati, Andhra Pradesh; NRCG (Junagadh, Gujarat); Jalgaon, Maharashtra; and ICRISAT) and one location in Australia (Kingaroy, Queensland), are described. The trait-based (indirect) selection programme combined high transpiration efficiency, harvest index and transpiration using a Selection Index approach. F1 and F2 plants were grown under non-stressed conditions to maximize seed multiplication. The F3 progenies were divided between trait-based and empirical selection approaches. The F2:3 progeny bulks were evaluated for pod yield, total dry matter, transpiration efficiency, harvest index and transpiration. Some 400 progenies incorporating representative members from each cross were carried forward. The carried-forward F2:4 progeny bulks were grown under stressed and non-stressed conditions, and the aforementioned parameters were re-evaluated. The selected F2:4 progenies were used to generate 5 F2:5 families at each site for each selection method. The replicated field trials were conducted in 2000/01. For the empirical (direct) selection programme, the procedure involved selection for pod yield. The procedure was similar to that of the trait-based selection, except that selections were conducted in an appropriate target environment as chosen by the relevant breeding programme (for example, under rainfed or irrigated conditions at the main experimental site). By the end of the selection cycles, the empirical selection approach supplied a subset of F2:5 progenies for inclusion in multilocation testing