Application Of MeJA In Control Of Rice Florescence And Flowering Time In Hybrid Rice Seed Production For Higher Seed Yield

CMS-ID lineⅡ32A and CMS-WA Zhenshan 97A were used to test the effect of MeJA on the regulation of florescence and flowering time. The materials included regular rices, photo-sensitive genic male sterile rices, several kinds of CMS lines and maintainer lines. The effects of MeJA on cleistogamy rice are also studied. The effect of MeJA on regulating synchrony of flowering time and florescence in several groups of rice are positive. Two kinds of regulators which contain lower concentration active compounds are developed. They have equal effect with MeJA on regulating flowering time.1 The effects of MeJA on flowering activity of male sterile lines, fertile rices and cleistogamy riceIn the starting period of florescence stage, the effects of MeJA on flowering activity ofⅡ32A and zhenShan97A were observed. MeJA made a remarkable alteration of florescence and flowering time. The florescence period was reduced from 5 days to 2 days. The flowering properties were more collective with larger amounts of opening flowers.A wide rang of male steriles were used to study their flowering characters before and after MeJA treatment. CMS lines include CMS-ID II 32A, CMS-WA Zhenshan 97A, CMS-ZD XieqingzaoA, CMS-HL 30A, CMS-BT 50A and photo-sensitive genic male sterile rice 11s, 22s. All these male sterile lines showed similar flowering characters subjected to MeJA treatment. Fertile rice and maintainer lines such asⅡ32B, Xieqingzao B, Zhengshan 97 B and regular rice D17, R174, R354 showed different flowering behavior from male sterile lines to MeJA. Male fertile lines were less sensitive to MeJA than sterile lines. There were only weak reactivity in fertile rice flowering to MeJA when the treatment are taken before original starting time of flowering. And no sign of inducement are presented in Zhenshan97B and R354 when the treatment was meeting the original flowering time. Instead of makeing flowering more concentrated, the flowering of fertile lines became more scattered after MeJA treatment.MeJA had no effect on inducing floret opening of cleistogamy rice. The structure of occluding and lodicule of cleistogamy rice were found much stronger in compare to normal rice and wild type.2 Using MeJA to regulate florescence and flowering time in hybrid seed production to improve seed yieldThe combinations of hybrid seed production Y22S×R26, Y22S×Xianghui, Zhongxing S×NHR1, guangzhan 63S×NHR1, Y 46S×NHR1, 32A×32B were treated with 3.0mmol/L MeJA. The yields of hybrid seeds were increased remarkably ranging from 23.8％to 215％. And there were no significant negative effects on the quality of the hybrid seeds. Effects of MeJA to growth, fertility and seed development of male sterile lines were also observed. MeJA had no effects on restoring the fertility of male sterile lines, though it decreased the growth and spike elongation. The results indicated that application of MeJA should be safety for the purity of hybrid seeds.