Variability, correlation and path studies for yield and quality traits in irrigated upland rice (Oryza sativa L.)

Analysis of variance indicated the existence of significant differences among all genotypes for twenty five yield and quality traits studied in 36 genotypes suggesting the existence of sufficient amount of variability. The highest estimates of PCV and GCV were observed for alkali spreading value (37.0, 35.4), straw yield per plant (34.5, 33.2), harvest index (33.2, 30.9), water uptake (28.7, 27.5), panicle weight (25.7, 25.3), filled seeds per panicle (24.5, 23.6), yield per plant (23.4, 22.5) and head rice recovery (21.3, 20.7). High heritability coupled with high genetic advance as percent of mean exhibited by alkali spreading value (91.4, 69.7), straw yield per plant (92.8, 65.8), harvest index (86.8, 59.3), panicle weight (96.7, 51.3), filled seeds per panicle (95.7, 49.3), panicle density (95.6, 46.2) head rice recovery (94.6, 41.5) and effective tillers (90.6, 36.6) indicating preponderance of additive gene action and these traits can be improved through simple selection. Correlation studies revealed that grain yield per plant has shown significant positive effect with panicle length (0.395), panicle weight (0.312) and effective tillers (0.268) while, head rice recovery exhibited significant positive association with milling percent (0.675) and hulling percent (0.376) at genotypic level. The results of path analysis indicated that panicle density (0.985) followed by straw yield per plant (0.495), effective tillers (0.370) and days to 50% flowering (0.282) had maximum direct effect on grain yield per plant. Milling percent (0.593) had shown direct positive effect on head rice recovery whereas length/breadth ratio (0.105), kernel breadth after cooking (0.033), kernel elongation ratio, volume expansion ratio, alkali spreading value has shown positive effect at phenotypic level and kernel length after cooking (0.0014) at genotypic level. Suggesting that these traits may be considered as prime traits during course of selection to have high yield potential with good quality traits in case of rice.