结实期土壤水分亏缺影响水稻籽粒灌浆的生理原因.pdf

植物生态学报 2011, 35 (2): 195–202 doi: 10.3724/SP.J.1258.2011.00195 Chinese Journal of Plant Ecology 结实期土壤水分亏缺影响水稻籽粒灌浆的生理原因 1,2* 1 2 2 王 维 蔡一霞 杨建昌 朱庆森 1华南农业大学农学院, 广州 510642; 2扬州大学, 江苏省作物遗传生理重点实验室, 扬州 225009 摘 要 通过分析结实期土壤水分亏缺对水稻(Oryza sativa)籽粒中蔗糖向淀粉合成的生理代谢中关键酶活性及籽粒灌浆的 调节作用, 探讨土壤水分亏缺影响水稻籽粒灌浆的生理机制。结果表明, 适度土壤水分亏缺诱导了灌浆高峰期(花后15–20天) 水稻籽粒中蔗糖合成酶、腺苷二磷酶葡萄糖焦磷酸化酶、可溶性淀粉合成酶及淀粉分支酶活性的增加, 提高了籽粒灌浆中前 期(花后10–20天)籽粒中淀粉积累速率和籽粒灌浆速率。但在灌浆后期(花后20–30天)籽粒中, 上述关键酶活性下降较快, 籽粒 活跃灌浆期明显缩短, 灌浆前中期灌浆速率的增加不能完全补偿灌浆期缩短带来的同化物积累损失, 导致水分亏缺处理水稻 籽粒充实不良, 结实率、籽粒重和产量显著降低。研究认为, 灌浆期土壤水分亏缺引起的灌浆后期籽粒中蔗糖向淀粉合成代 谢中一些关键酶活性快速下降和籽粒内容物的供应不足是籽粒淀粉积累总量减少、粒重降低的主要生理原因。 关键词 籽粒灌浆, 水稻, 土壤水分亏缺, 淀粉合成, 蔗糖 Effects of soil water deficit on physiological causes of rice grain-filling 1,2* 1 2 2 WANG Wei , CAI Yi-Xia , YANG Jian-Chang , and ZHU Qing-Sen 1College of Agronomy, South China Agricultural University, Guangzhou 510642, China; and 2Key Laboratory of Crop Genetics and Physiology of Jiangsu Province, Yangzhou University, Yangzhou, 225009, China Abstract Aims Our objective was to elucidate the physiological causes of the influence of soil water deficit on grain-filling and rice (Oryza sativa) yield by evaluating enzyme activities involved in sucrose-starch synthesis during the grain-filling period. Methods Two rice cultivars (‘Shanyou 63’ and ‘Pc311/Zaoxiandang’) were grown in cement containers. Controlled soil water deficit was imposed at 9th day after flowering because the division of endosperm cells is sensitive to water deficit. The activities of key enzymes involved in th