Seed Quality Effection Of GA₃Spraying Dosage And The Harvestibg Time In Seed Production Of Hybrid Rice Zhulinagyou312

Study on gibberellin dosage of raising flower of female parents of early hybrid rice combination "zhuliangyou312" in initial panicle stage and full panicle stage, and harvesting time after pollinating effect on seed characters. Main result shows:1. When panicle index of "zhuliangyou312" female parent reach35%, sperately spray8、12、16、20g/667m2gibberellin dosage. Plant height increase with gibberellin dosage increasement. stem width and thickness of forth to last internode is bigger than that of third to last, it is normal that internode width of lower part is bigger than that of upper part. stem length of forth to last is longest with gibberellin16g/667m2; that of third and second to last with16、20g/667m2is longer than that of other gibberellin dosage. Plant fresh weight except root increase obviously, Grain rate of unopened neck reduce.2. When panicle rate of "zhu1S"reach35%,spray8、12、16、20g/667m2gibberellin.unopened panicle rate is11.33%、8.24%、3.18%、2.76%. that with8g/667m2gibberellin is11.33%, higher than other concentration.unopened panicle rate reduce with gibberellin dosage increase.neck length and grain seed of unopened panicle rate is smaller with all four gibberellin dosage.3. Seed setting rate is separately52.65%、54.45%、59.15%、58.20%under four different gibberellin dosage. It shows that spraying suitable gibberellin dosage can increase out-crossing rate of female parent. There is no difference in1000-grain weight and germination rate with four gibberellin dosage treatment. Seed germinatin rate reach88.5%～90%after mature with harvest and dry in time.that shows "zhuliangyou312"has higher seed germination rate in seed production4. There is no difference in plant height of "zhu1S" under spraying "1.2g/667m2gibberellin and the same concentration water. spraying gibberellin in female parent full panicle stage can increase fulled grain rate. seed unopened spikelet rate under spraying water is obviously higher than that of other treatment, blank powder rate under spraying water is obviously higher than that of spraying1、2g/667m2gibberellin.5. Green grain rate harvested in12-22days period after pollination reduce from22.15%to0.80%, In twenty-second days,there is no green grain. normal colour grain rate increase74.15%to90.46%.with day increase,unnormal color grain rate increase. Unopened spiklet grain rate increase to20.10%. seed germination rate80.65%in twelve day increase to90.15%in twenty day6、Harvesting timely and storage in usual condition,after6months,seed germination rate reach more than80%. That in16-20days after pollination reach90%. That in12days can not reach national standard because of unmature seed existence, so it not suitable to harvest.