Heterosis breeding in sunflower (Helianthus annuus L.) in India: Present status and future prospects

Abstract

Sunflower (Helianthus annuus L.) is a highly cross pollinated crop and the main objective of sunflower breeding is to develop high yielding hybrid cultivars with stable and high yield through exploitation of heterosis. Hybrid sunflower became a reality with the discovery of cytoplasmic male sterility and effective male fertility restoration system during 1970. Hybrids were preferred by growers worldwide due to high seed yield and quality potential, homogeneity, resistance to biotic stresses, synchronous maturing and ease of cultural applications. The inclusion of sunflower under AICRP and testing of experimental hybrids started as early as 1975 and first ever indigenous hybrid BSH -1 (CMS-234A x RHA-274) from public sector was released for commercial cultivation in 1980. Since then the hybrid breeding program has been quite successful and 45 CMS based productive single cross hybrids were developed by both public (34) and private sectors (11) in India. Despite these successes, problems in the form of stagnating and unstable yields, genetic vulnerability and susceptibility to various diseases like powdery mildew (PM), downy mildew (DM), Alternaria leaf spot, sunflower necrosis disease (SND) and sunflower leaf curl virus (SuLCV) are limiting sunflower productivity in India. One of the major challenges would be to develop newer and superior hybrids for diverse situations in order to sustain the competitive ability of sunflower vis-a-vis other crops. At present, much of the plant breeding research in All India Coordinated Research Project (AICRP) is directed towards exploitation of heterosis utilizing few CMS and fertility restorer lines.There is an urgent need for new restorers and CMS lines with diverse cytoplasm having several desirable attributes like high seed yield, high oil content, early maturity coupled with resistance to biotic and abiotic stresses. Towards this direction, attempts are being made to augment exotic breeding lines and also develop superior maintainer (B) and restorer (R) lines through appropriate gene pools, population improvement, recombination breeding and pre-breeding.