Application Of MeJA And Its Mixtures In Hybrid Rice Seed Production

This study used6hybrid rice combinations of Zhenshan97A/Zhehui963, BoyouA/Pinghui141(summer seed production), Yue4A/Huahui4, Zhong3A/Zhonghui286,Boyou A/Pinghui141(autumn seed production) and K18A/Minghui77as experimentmaterials to investigate the effect of MeJA and its mixtures on the application in hybridseed production. Solutions of control,1.0mmol/L MeJA,1.0mmol/L MeJA+50mg/L ALA,1.0mmol/L MeJA+500mg/L ABA and1.0mmol/L MeJA+0.025mg/L epiBR treatmentswere sprayed to the female parent plants on the third day of the flowering stage, and theeffects of MeJA and its mixtures on the floret opening and closing, percentage of exertedstigma, stigma vitality,1000-grain weight, outcrossing rate, hybrid seed production yieldand percentage of glume-gaping grain were studied. The experiments results indicated:(1) All MeJA and its mixture treatments promoted floret opening in female parents,the maximum period of floret opening occurred1h after the treatment. Mixture of MeJAand epiBR exhibited synergistic effect in promoting floret opening in Zhenshan97A,Boyou A and Zhong3A. MeJA+ABA promoted floret closing in Yue4A, Zhong3A, BoyouA(autumn seed production) and K18A.(2) MeJA+ALA and MeJA+epiBR significantly increased percentage of total exertedstigma in Zhenshan97A and percentage of single exerted stigma in Boyou A(autumn seedproduction). MeJA+epiBR significantly increased percentage of total exerted stigma inK18A and percentage of total and double exerted stigma in Yue4A. MeJA+epiBR, MeJAand MeJA+ALA significantly increased percentage of single exerted stigma in Zhong3A.MeJA and its mixtures significantly increased percentage of single exerted stigma inBoyou A(summer seed production).(3) Except for MeJA to K18A, MeJA+ABA to Yue4A and MeJA+ALA to Yue4A andBoyou A(autumn seed production), MeJA and its mixtures generally increased the stigmavitality on second day in the female parents.(4) MeJA+ALA and MeJA+epiBR significantly incresed outcrosing rate in Zhenshan97A/Zhehui963and Yue4A/Huahui4. MeJA+epiBR significantly incresed outcrosing ratein Boyou A/Pinghui141(autumn seed production) and K18A/Minghui77.(5) MeJA+epiBR significantly increased theoretical and actual yield of hybrid seeds in Zhong3A/Zhonghui286，K18A/Minghui77and Zhenshan97A/Zhehui963withincreasing rate of6.6%and12.4%,40.6%and45.4%,55.3%and54.0%respectively;increased theoretical yield of hybrid seeds in Boyou A/Pinghui141(autumn seedproduction) with a increasing rate of9.8%. MeJA+ALA significantly increased theoreticaland actual yield of hybrid seeds in Zhenshan97A/Zhehui963and Yue4A/Huahui4withincreasing rate of65%and50.2%,18.9%and14.5%respectively. MeJA significantlyincreased actual yield of hybrid seeds in Zhenshan97A/Zhehui963. MeJA and its mixturessignificantly increased theoretical and actual yield of hybrid seeds in Yue4A/Huahui4.(6) MeJA and its mixtures exhibited no obvious impact on percentage ofglume-gaping grain in Zhong3A/Zhonghui286, but significantly increased percentage ofglume-gaping grain in other5hybrid rice combinations.