Combining ability studies for yield components, quality characters and relative susceptibility to fruit and shoot borer in brinjal

Abstract

Six diverse brinjal lines were crossed in a diallel fashion, excluding reciprocals to obtain fifteen cross combinations to study combining ability for yield components, quality characters and relative susceptibility to brinjal fruit and shoot borer. Significant differences were observed among genotypes for most of the characters studied. Both additive and non-additive gene action conditioned most of the characters while non-additive gene action was preponderant for the control of total phenol content of fruit, seed protein content and shoot infestation by borer. Maximum significant gca effects in desired directions were registered by Garia for 7 characters followed by BCB-40, BCB-50 and Punjab Sadabahar for 6 characters. However, considering the second highest per se performance for marketable fruit yield/ plant (2.59 kg/plant) along with second lowest severity of fruit borer infestation (18.55%) together, the parental line BCB-40 emerged as the best followed by BCB-30, being the highest yielder (2.69 kg/plant) and low severity of fruit borer infestation (22.07%). The most promising cross combination Garia × Punjab Sadabahar registering the second highest marketable fruit yield per plant (3.74 kg / plant) exhibited the highest significantly positive sca effects for marketable fruit yield/ plant along with high and significantly positive sca effect for plant height, fruit pedicel length, fruit weight, fruits per plant and total phenol content of shoot and significantly negative sca effect for fruit infestation by brinjal fruit and shoot borer. Keeping in view of low narrow sense heritability for some important characters viz., fruit weight, marketable fruit yield per plant, total phenol content of fruit and fruit infestation by brinjal fruit and shoot borer selection should be based primarily on replicated family testing in F3 and later generations. In the perspective of importance of nonadditive genetic variance along with additive genetic variance for the conditioning of most of the characters, heterosis breeding to develop high yielding hybrids possessing better fruit size, colour, quality and less susceptibility to brinjal fruit and shoot borer may be the best breeding strategy.