Gene Action and Combining Ability for Grain Yield and Its Components in Rice

TLDR: Predominance of dominant gene action for all the traits studied except for plant height and hundred grain weight thus suggesting that the hybrid breeding must be strongly pursued for the exploitation of the yield advantage over the inbred varieties.

Abstract: In this study, an effort was made to identify good parents and nature of gene action governing different characters of rice by line (4 restorers) × tester (2 cytoplasmic male sterile lines) analysis. The trial comprising 8 hybrids and their parents were laid out in randomized block design with 3 replications and characterized for yield and nine yield component traits. In the present study, the ANOVA for combining ability revealed significant differences between the treatments (genotype) for all the traits studied and amongst the treatments the mean sum of square (MSS) due to parents showed significant differences for all the traits. The grain yield, grain number per panicle, plant height and days to fifty percent flowering appears to be the key determining traits and showed significant differences for the lines, testers, line × testers. Parents with low × high general combining ability (GCA) effects resulted in heterotic hybrid combination like the IR68281A/IR68749R. Interestingly, we found low ×...