HETEROSIS AND COMBINING ABILITY ANALYSIS IN BASMATI RICE HYBRIDS
F.A.Faiz, M. Sabar, T.H.Awan, M.Ijaz and Z.Manzoor
Rice Research Institute, Kala Shah Kaku, Lahore.
ABSTRACT
Two CMS lines, IR69616A and IR70369A were crossed with 60001 (a fine grain aromatic advance line) and Basmati 385 (a commercial Basmati variety). Fine grain aromatic line, 60001 and Basmati 385 were used as testers. Two lines x two tester mating design along with four genotypes and their F1’s were studied to estimate heterosis and combining ability effects in yield and yield influencing traits i.e., plant height, number of productive tillers per plant, number of spike-lets per panicle, number of filled grains per panicle, sterility %age and grain yield. Significant differences were observed in lines, testers and line x testers. Both the CMS lines reduced the plant height of their respective F1 hybrids. The highest positive heterosis over better parents was observed for grain yield (41.83 %), number of productive tillers per plant (11.04 %) and number of filled grains per panicle (7.39 %) in the cross of IR69616A x Basmati 385. GCA effects were found higher for filled grains and number of spike-lets per panicle. Except plant height, mean performance of the parents was positively and strongly correlated with GCA effects. Within the CMS lines, IR 69616A found to be a good general combiner for most of the traits. Where as within the testers, Basmati 385 was observed to be a good general combiner for most of the traits.
Key words: Heterosis, combining ability, line x tester, rice hybrids. |