Vol. 8, Issue 12, Part C (2024)

The five male sterile lines of different cytoplasm (A1, PT732A and A4) and sixty diverse restorers were crossed in line × tester mating design. The resultant 300 hybrids were evaluated along with parents and checks in RBD design at ARS, Malnoor during Kharif 2019.Out of these 90 high fertility restorer hybrids were selected (5 lines x 18 testers) and were assessed for combining ability and heterosis for ten yield and yield related traits. Further overall GCA status of a parent and SCA status of crosses were determined. The estimates of general combining ability suggested that parents, ICMA94222 and 841A emerged as best general combiner by registering desirable significant GCA effect for as many as five characters. Among male parents SGRLT-17, PDRLT-8, EMRLT-131, EMRLT-43, TPRLT-109, LPRLT-114, EMRLT-127 and EMRLT-139 exhibited significant and positive GCA effects for important traits. The relationship between overall GCA and SCA status revealed that heterotic hybrids could be obtained from parents with any combination of GCA i.e., H x H, H x L, L x H and L x L but probability of it to be a H × L and H × H combination was higher than the probability of finding it to be a L × L. The 30 hybrids recorded highly significant SCA effects for grain yield per plant in which 18 (33%) crosses belonging to A1, 5 (28.%) from PT732A and 7 (39%) crosses from A4 and heterosis was observed in all sources of cytoplasm. However, PT732A and A4 cytoplasm crosses have expressed equal/high mean SCA effect and heterosis for grain yield per plant compared to A1 cytoplasm crosses. It clear that heterosis can be exploited on commercial SCAle in different CMS sources as like A1 source hybrids and cytoplasmic base of the hybrids can be diversified by intensifying the restorer-breeding programme in pearl millet.