Exploration of Genetic Variability and Trait Association in High Protein Landraces of Rice (Oryza sativa L.)

The present investigation was carried out at the Indian Institute of Rice Research farm, ICRISAT, Hyderabad with 31 genotypes of rice in a randomized block design with three replications, and observations were recorded on grain yield, yield components and quality characters. Analysis of variance revealed significant differences among the genotypes for all characters studied. The studies on variability, heritability and genetic advance as per cent mean thus revealed high GCV and PCV for grains panicle-1 and iron content. High heritability coupled with high genetic advance as per cent mean was recorded for plant height, ear bearing tillers plant-1, grains panicle-1, grain yield plant-1 and iron content indicating, the effectiveness of simple selection for improvement of these traits. The results on character associations and path analysis revealed positive and significant association coupled with high positive direct effect for ear bearing tillers plant-1, panicle length, grains panicle-1, and amylose content indicating the effectiveness of direct selection for these traits in the improvement of grain yield plant-1. However, for test weight, days to 50 percent flowering, plant height, head rice recovery (%), and zinc content, indirect effects seemed to be the cause of correlation, while for days to maturity, protein and iron content, the use of restricted simultaneous selection model is suggested with restrictions imposed for nullifying the undesirable indirect effects in order to make use of the high positive direct effect observed for these traits on grain yield plant-1.