Identification of heterotic parents is prerequisite in hybrid breeding. Combining ability analysis is useful in selecting the parents and desirable cross combinations to be used in any breeding programme to produce superior hybrid. Four identified maintainers (Kanchana, Jyothi, Aruna and Bharathy) and 11 restorers (Remya, Jayathi, Swarnaprabha, Manupriya, Annapoorna, Kanakom, Mattatriveni, Varsha, Aiswarya, Neeraja and Pavizham) were crossed in L × T fashion and combining ability of parental lines were carried out in F1 generation. The GCA variances were significant for plant height, days to maturity, number of spikelet/panicle and number of grain/panicle indicating operation of additive gene action. On the other hand, SCA variances were highly significant for all characters except for total number of tillers, number of productive tillers and grain length/breadth ratio indicating the predominance of non-additive gene action. In order to assess heterosis in different combination of the identified maintainers and restorers an L × T analysis was done with maintainers as the lines and restorers as the testers. Perusal of findings indicated that line Jyothi is a good general combiner as it recorded a high over all GCA status. The hybrid Aruna × Varsha was the best specific combiner followed by, Jyothi × Pavizham and Kanchana × Mattatriveni. Three crosses viz; Aruna × Varsha, Jyothi × Pavizham and Bharathy × Annapoorna registered high significant heterosis for grain yield per plant over midparent, better parent and standard check Uma.

GCA, CSA, Line, Tester, Hybrid

In order to assess heterosis in different combination of the identified maintainers and restorers an L × T analysis was done with maintainers as the lines and restorers as the testers. Perusal of findings indicated that line Jyothi is a good general combiner as it recorded a high over all GCA status. The hybrid Aruna × Varsha was the best specific combiner followed by, Jyothi × Pavizham and Kanchana × Mattatriveni. Three crosses viz; Aruna × Varsha, Jyothi × Pavizham and Bharathy × Annapoorna registered high significant heterosis for grain yield per plant over mid parent, better parent and standard check Uma.

Rajib Das, Denisha Rajkhowa, Senpon Ngomle and Bapsila Lointongbum (2023). Combining ability analysis for grain yield and yield contributing characters in rice (Oryza sativa L.). Biological Forum – An International Journal, 15(12): 138-148.