Classification of new germplasm into existing heterotic groups of pearl millet [Pennisetum glaucum (L.) R. Br.]

The study assigned new germplasm, which includes populations and inbreds, to established heterotic groups using various approaches to broaden the existing genetic base while maintaining the heterotic pattern in pearl millet [Pennisetum glaucum (L.) R. Br.]. It utilized 13 pearl millet populations of African and Asian origins and 24 new inbred parents from ICRISAT's breeding program. Testers, both inbred and composite, were employed to categorize these materials into heterotic groups. Different sets of line x tester crosses were generated and evaluated during the rainy season at multiple locations in India. The pearl millet populations were assigned to heterotic group B (seed parental groups) (HGB1 and HGB2) and heterotic group R (pollinator parental groups) (HGR1 and HGR2) based on general combining ability (GCA) and specific combining ability effects. Composite testers were found to be more effective for the heterotic grouping of pearl millet populations. New inbred lines were classified into HGB and HGR based on GCA and hybrid performance using opposite heterotic group testers and also using genetic similarity obtained from genotype-by-sequencing data.The new germplasm classified into heterotic groups will help enhance the genetic gain for the long-term success of pearl millet hybrid breeding programs.