tailieunhanh - Studies on combining ability and panicle mite resistance in hybrid rice (Oryza sativa L.)

Studies were conducted on the combining ability and relative resistance of rice hybrids against panicle mite (Steneotarsonemus spinki) during Kharif, 2017. Six cytoplasmic male sterile lines were crossed to seven testers in Line X Tester mating design to produce 42 hybrids. The parents and hybrids along with two checks were evaluated. The analysis of variance for combining ability showed that mean sum of square due to lines, testers and the interaction between lines and testers was significant for most of the characters under study. The result revealed that peak incidence of mite occurred at the ripening stage but significantly higher number of mite population and damage symptoms in all plants were observed at the panicle emerging to ripening stage. Out of 42 rice hybrids and 13 parental lines evaluated, based on GCA and SCA effects two parental lines viz., JMS 20B and JR 80 and fifteen hybrids were of good yield potential and resistant against panicle mite with no damage symptoms. The results on categorization of resistance revealed that, five parental lines and eleven hybrids contribute for moderate resistance. Six parents and sixteen hybrids were found susceptible against Steneotarsonemus spinki. | Studies on combining ability and panicle mite resistance in hybrid rice (Oryza sativa L.)