Effects Of Droughty And Rewatering At Grain Filling Stage On Yield And Concerned Physiological Index In Different Yield Potential Double-season Rice Varieties

In order to improve whether there was compensatory growth effect on rewatering after droughty at late growth stage,the relationship between yield performance and rehydration after drought response.yield potential performance of the early rice super rice varieties GanXin203and control variety Ganxin206and late rice super rice varieties Wufengyou T025and control a variety Jinyou207were selected to drought(early rice drought5d, late rice drought8d), rewatered until soil whitish cracked.The differences of seed setting and yield, the second leaf osmotic regulator, membrane lipid peroxidation product malondialdehyde (MDA), the photosynthetic indicators and chlorophyll content, the activities of protective enzymes, endogenous hormones and813C physiological indicators of all varieties.The results showed that:1.Yield and yield components were decreased to varying degrees, compensation effect of early rice yield was not significant on water stress and rewatered at grain filling stage, But there are some differences between the varieties. Yield decline of Ganxin203was less than Ganxin206; that was, yield stability of Ganxin203was better.seed setting rate of decline in poor close. The grain weight decline of Ganxin203was significantly lower than Ganxin206. Why the yield stability of the early rice Ganxin203was higher than Ganxin206at the grain filling stage on drought and rewatered, the possible reason was that the ascensional range compared to the control which had maintained a water layer of SOD activity, POD activity, free proline content, soluble sugar content, chlorophyll content, net photosynthetic rate, stomatal conductance, ABA content,IAA content,GA3content and ZR content were Ganxin203higher than Ganxin206on water stress, MDA content on the contrary; the ascensional range compared to the control which had maintained a water layer of SOD activity, POD activity, free proline content, soluble sugar content (except for the six days of rehydration), net photosynthetic rate, stomatal conductance and IAA content were Ganxin203higher than Ganxin206after rewatering, MDA content on the contrary.2.Yield and yield components were decreased to varying degrees, compensation effect of late rice yield was not significant on water stress and rewatered at grain filling stage, but there were some differences between the varieties. Yield decline of Wufengyou T025was less than Jinyou207, that was, yield stability of Wufengyou T025was better. Seed setting decline rate of Wufengyou T025was significantly higher than Jinyou207, but the grain weight decreased slightly lower than Jinyou207. Why the yield stability of the early rice Ganxin203was higher than Ganxin206at the grain filling stage on drought and rewatered, the possible reason was that the ascensional range compared to the control which had maintained a water layer of SOD activity, POD activity, free proline content, soluble sugar content, chlorophyll content, net photosynthetic rate, stomatal conductance,δ13C, ABA content, IAA content, GA3content and ZR content were Wufengyou T025higher than Jinyou207on water stress, MDA content on the contrary; the ascensional range compared to the control which had maintained a water layer of SOD activity, POD activity, free proline content, soluble sugar content, chlorophyll content, net photosy-nthetic rate, stomatal conductance,δ13C and IAA content were Wufengyou T025higher than Jinyou207after rewatering(except for the six days of rehydration of free proline and soluble sugar content), MDA content on the contrary.