Heterosis and combining ability studies for economically important traits in sunflower (Helianthus annuus L.).

Abstract

The production of good quality edible oil is very important for balancing the demand and supply for both domestic as well as industrial purposes, which is possible only through the development of high yielding sunflower hybrids. So, for developing such hybrids knowledge on combining ability and nature of gene action are important for commercial exploitation of heterosis. Keeping in view of the objectives the present investigation was carried out at ICAR-Indian Institute of Oilseeds Research, Rajendranagar, Hyderabad during kharif, 2019 where crossing programme was carried out in line x tester fashion by utilising five lines and 10 testers for synthesizing 50 F1 hybrids which were evaluated for different economically important traits during rabi, 2019-2020. The analysis of variance for combining ability estimated a significant amount of variability for all the traits. The line, ARM-243A, recorded the highest significant and positive gca effect for 100 seed weight, volume weight and seed yield and among testers, PM-81 recorded significant positive gca effect for seed yield and RHA-6D1 for oil content. The sca effects revealed that the cross, CMS-234A x PM-81 recorded highest significant positive sca effect for seed yield, whereas the cross, CMS-335A x RGP-50-P1-S4 exhibited sca effects in desired direction for oil content. The estimates of variance due to sca was greater than gca for all the traits indicating predominance of non-additive gene action governing the inheritance of the traits revealed that the traits can be improved by exploitation of heterosis breeding. Hence, all the three types of heterosis was estimated and the studies revealed that the crosses, CMS-234A x PM-81 and ARM-243A x PM-81 recorded the highest significant standard heterosis over the checks for seed yield. The cross, CMS-335A x RGP-50-P1-S4 recorded highest significant average heterosis, heterobeltiosis and standard heterosis for oil content. The genotypes which were superior for most of the yield and oil content related traits could be further evaluated across locations and over seasons before they are being exploited commercially.