Heterosis and Combining Ability for Quality Components in Rice

Heterosis and combining ability for three quality components, protein content, amylose content, alkali spreading value, and yield were studied in a diallel involving eight varieties of rice. Heterosis above the mid-parent was significant in five crosses for protein, in one cross for amylose content, and in three crosses for alkali spreading value. The average heterosis values were negative. Yield showed positive heterosis in most of the hybrids and eight of them were significantly high. The combining ability and component of vairance analysis indicated importance of both additive and non-additive gene action for alkali spreading value and predominant non-additive gene action for protein content and yield. The parent T ‘(N) 1’, was the best general combiner for all characters followed by ‘CRHP 8’. In. general, non-significant association was observed between protein, amylose content, and alkali spreading value; however, protein content showed a negative correlation with yield, although it was not significant.