Frequency of Heterotic Hybrids in Relation to Pare

Authors: C M Keerthi S Ramesh M Byregowda A Mohan Rao

Publish Date: 2016/11/16

Volume: 88, Issue: 3, Pages: 923-933

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Abstract

Though F1 hybrids are not the immediate cultivar option development of heterotic F1 hybrids is relevant from view point of deriving pure lines the only cultivar choice in dolichos bean a predominantly selfpollinated grain legume crop species Heterotic F1 generates a high frequency of productive derivatives in F3 and later generations as compared to nonheterotic F1 The criteria such as combining ability and genetic diversity between parents are being commonly used to develop heterotic hybrids In this context an investigation was carried out at University of Agricultural Sciences Bengaluru India to test the predictability of frequency of heterotic hybrids based on parental gca effects and genetic diversity in dolichos bean The 48 F1 hybrids generated by crossing 12 lines and 4 testers were evaluated along with their parents for 6 quantitative characters The overall gca status high and low of each parent and overall sca and heterotic status high and low of each hybrid for 6 characters were determined Based on overall gca status and genetic divergence of parents the hybrids were grouped into different classes The hybrids involving parents contrasting for overall gca status and/or those involving parents with intermediate genetic divergence were more frequently heterotic than those involving comparable gca status with extreme genetic divergence Thus there exists a limit to parental divergence for the occurrence of heterosis It is hence desirable to involve parents with intermediate genetic divergence and contrasting gca effects to recover higher frequencies of heterotic hybrids for economic traits in dolichos beanSenior author gratefully acknowledges Kirkhouse Trust United Kingdom for providing financial support in the form of international fellowship for conducting thesis research for partial fulfilment for the award of PhD degree at University of Agricultural Sciences Bangalore India

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