Predicting the Frequency of Transgressive RILs and Minimum Population Size Required to Recover Them in Dolichos Bean [Lablab purpureus (L.) Sweet]

Abstract

Background: Allocation of resources only to a few promising segregating populations that are likely to result in high frequency of transgressive recombinant inbred lines (RILs) for use as pure-line cultivars would help enhance efficiency of breeding self-pollinated crops including dolichos bean. The use of an objective criterion to identify promising segregating populations is therefore assumes importance. The prediction of frequency of transgressive RILs that could be derived from advanced generations of segregating populations of crosses is one such criterion. Methods: We predicted the frequency of RILs that transgressed the better parent (HA 5) from two reciprocal crosses derived from two elite but genetically diverse parents (HA 4 and HA 5) for four quantitative traits based on estimates of mid parental value [m], additive genetic effects [a] and additive genetic variance [σ2A]. Result: The frequency of transgressive RILs predicted from H 5 × HA 4 was higher than those predicted from H 4 × HA 5 for primary branches plant-1, pods plant-1 and grain weight plant-1, while it was comparable between the crosses for pod weight plant-1. The required minimum population size was relatively smaller to recover the transgressive RILs from the cross which was predicted to result in higher frequency of RILs than that was predicted to result in lower frequency of RILs.

Assessment of Transgressive Segregants for Yield and its Component Traits in French Bean (Phaseolus vulgaris L.)

“…Maximum number of transgressive segregants was isolated for number of pods per plant and number of seeds per plant in F 2 and F 3 generation of chick peas (Sundaram et al, 2023). In an experiment, Basanagouda et al (2022) revealed higher transgressive RILs in crosses of dolichos bean for the concerned traits like number of branches per plant, number of pods per plant and seed weight per plant.…”

Predicting, Validation of Frequency of Transgressive Recombinant Inbred Lines and Minimum Population Size Required to Recover them in Groundnut (Arachis hypogaea L.)

“…Our study suggests this approach of identifying promising crosses in early segregating generations by predicting the frequency of transgressive RILs that could be recovered in advanced generations and minimum population to be raised to recover them is practical as plant breeders often develop F2 /F2:3 populations from large number of crosses. By using this strategy of identifying breeding potential of crosses one can select the best cross out of many crosses made in the process of development a pure-line cultivar [14,15].…”