Assessment of inter-relationships between yield and yield attributes for heat tolerance in rice (Oryza sativa L.)

Character association studies in 200 germplasm lines of rice for eleven characters at ICRISAT, Patencheru, Hyderabad revealed significant positive association of single plant yield with number of grains per panicle, spikelet fertility, 1000 grain weight, pollen viability, number of productive tillers per hill, panicle length, number of tillers per hill, days to 50% flowering and days to maturity. Estimates of direct and indirect effects of component characters on single plant yield at genotypic level revealed that number of grains per panicle contributed for maximum positive direct effect on single plant yield followed by 1000 grain weight, spikelet fertility, number of productive tillers per hill, pollen viability, panicle length and days to 50% flowering, Also, these traits had positive and significant association with grain yield. Critical analysis of character association and path analysis showed that these characters should be given importance to isolate superior lines with genetic potentiality for high grain yield.