不同泥沙含量下受淹胁迫对鄱阳湖平原双季稻生长与产量的影响

Effects of Flooding Stress on Growth and Yield of Double Cropping Rice in Poyang Lake Plain under Different Sediment Contents

为探究鄱阳湖平原区洪涝时期不同泥沙含量下受淹胁迫对双季稻生长及产量的影响,采用大田试验与室内分析相结合的方法,设置淹2/3株高和全淹2种受淹深度,S1(0 kg/m^(3))、S2(0.5 kg/m^(3))、S3(1.0 kg/m^(3))3种泥沙含量,对淹水后6、9 d早稻和中稻的生长指标和水稻产量进行了观测研究。结果表明:适度受淹刺激水稻伸长,节间不断分化,叶片伸长、增宽。早稻抽穗开花期受淹株高、节间长增加9.35%、12.75%,2/3淹下叶面积增加11.00%。但胁迫过大抑制水稻生长,中稻全淹下株高和分蘖数减小33.49%、29.28%,叶面积减小30.94%,此时中稻难以伸出水面,导致功能叶片附沙严重,泥沙含量增大进一步抑制了水稻生长。受淹导致早稻和中稻穗干物质量平均减小32.35%、58.72%(P<0.05)。结实率和千粒质量减小是早稻抽穗开花期受淹后产量下降的主要原因,此时泥沙含量和淹水时间的影响并不明显。中稻全淹下泥沙导致减产加剧,S2、S3下减产率比S1下显著增加31.63%、52.20%(P<0.05),此时产量下降是穗长、有效穗数、穗粒数、结实率、千粒质量综合作用的结果。研究结果可为鄱阳湖平原区洪涝灾害治理和粮食安全保障提供理论和技术支撑。

To investigate the effects of flooding stress on the growth and yield of double cropping rice under different sediment contents during the flood period in the Poyang Lake Plain area,a combination of field experiments and indoor analysis was used.Two types of flooding depths,including 2/3 plant height and full flooding,and three sediment contents,S1(0 kg/m^(3)),S2(0.5 kg/m^(3)),and S3(1.0 kg/m^(3)),were set up.The growth indicators and rice yield of early and middle rice were observed and studied 6 d and 9 d after flooding.The results showed that moderate flooding stimulated rice elongation,continuous internode differentiation,and increased the leaf elongation and width.The height and internode length of flooded plants were increased by 9.35% and 12.75% during the heading-flowering stage of early rice,and the leaf area under 2/3 flooding was increased by 11.00%.However,excessive stress inhibited rice growth.The plant height and tiller number of middle rice were decreased by 33.49% and 29.28%,and the leaf area was decreased by 30.94%.At this time,it was difficult for middle rice to extend beyond the water surface,leading to severe sand deposition on functional leaves.The increase in sediment content further inhibited rice growth.Flooding resulted in an average reduction of 32.35% and 58.72% in dry matter weight of early and middle rice panicles(P<0.05).The decrease in seed setting rate and thousand grain weight was the main reason for the decrease in yield of early rice after being flooded during the heading-flowering stage,and the influence of sediment content and flooding time was not significant at this time.Under full submergence of sediment,the yield reduction of medium rice was intensified.The yield reduction rate under S2 and S3 was significantly increased by 31.63% and 52.20% compared with that under S1(P<0.05).At this time,the yield decrease was the result of the comprehensive effect of spike length,effective panicle number,grain number per panicle,seed setting rate,and thousand grain weight.The research results can provide theoretical and technical support for flood disaster management and food security guarantee in the Poyang Lake Plain area.