Heterosis for yield and yield contributing characters in rice (Oryza sativa L.)

An investigation was taken up to study the magnitude of heterosis for nine characters in rice viz., days to 50 percent flowering, days to maturity, plant height at maturity, productive tillers per plant, tillers per square meter, thousand grain weight, grains per panicle, and yield per plant. The base material for this experiment consisted of 36 F1s involving three cytoplasmic male sterile lines (CMS) and twelve diverse restorers in line x tester mating design along with best varietal check Phule Samruddhi and best hybrid check Sahyadri-4. Hybrids were evaluated in randomized block design (RBD) with three replications. Heterosis over mid parent, better parent and standard checks revealed that experimental hybrids had higher heterotic effect for all the characters under study. The estimates of heterosis revealed that, there was a large amount of better parent and check parent 102 heterosis thus RTN17-A x RPHR51, RTN6-A x IR40750, RTN17-A x RPHR2, RTN6-A x RPHR51, RTN6-A x IR66, IR58025 x IR61614, RTN17-A x IR61614 and RTN17-A x IR60199 were found to be most promising hybrids. The crossing of exotic male sterile lines with local restorers appears to be the right approach in getting heterotic combinations.