Assessment of breeding potential of crosses involving different numbers of parents for green fruit yield in chilli (Capsicum annuum L.)

Abstract

Cultivars derived from bi-parental crosses not only have a limited genetic base but also often lack the desired combination of traits, making them genetically vulnerable. Our hypothesis postulates that cultivars derived from populations of multiple parents are more likely to have greater trait means, genetic variability and thus a broader genetic base. To validate this hypothesis, the breeding potential of nine segregating populations derived from crosses with different numbers of parents of unequal population size ranging from 56 to 270 was field-tested for green fruit yield per plant during the rabi-summer season of 2020–21 at the experimental fields of the Department of Genetics and Plant Breeding, University of Agricultural Sciences, Bengaluru. The breeding potential of these nine segregating F2 populations was evaluated based on the mean values of quantitative traits, absolute range, standardised range (SR), transgressive segregation index (TSI) and the usefulness criterion (UC). Recognising that different statistical parameters can identify different populations with good breeding potential, UC served as an objective measure to identify populations with greater breeding potential. In particular, the segregating population resulting from a three-way cross hybrid (Gouribidanur (GB) × CMS 7B) × CMS 8B) showed increased estimates for trait means (379.24 g), SR (5.22), TSI (30.74) and UC (50906.4) for green fruit yield per plant. This segregating population could be advanced for the isolation of advanced breeding lines. In light of this study, the optimal number of parental lines required to generate potential segregating populations in future chilli breeding programme would be set at three.