水稻开花期一些生理生化特性与品种抗旱性的关系

Relationship Between Some Physiological and Biochemical Characteristics and Drought Tolerance at Rice Flowering Stage

【目的】探索水稻开花期适应干旱环境的生理生化机制,筛选水稻开花期抗旱性鉴定的生理生化指标。【方法】利用抗旱性不同的10个水、旱稻品种,在干旱棚内通过开花期水分胁迫,研究了叶片抗坏血酸(Vc)、游离氨基酸、可溶性蛋白质、丙二醛(MDA)等物质的含量和保护性酶活性的变化。【结果】开花期水分胁迫增加了叶片Vc、游离氨基酸、可溶性蛋白质和MDA含量,提高了超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)的活性。相关分析表明,在水分胁迫与对照条件下Vc、游离氨基酸、MDA含量和SOD活性的相对值与品种的抗旱系数有显著或极显著相关性。【结论】水、旱条件下Vc、游离氨基酸总量、MDA含量和SOD活性相对值可作为水稻开花期抗旱性鉴定指标,利用此4项相对值与抗旱系数所建立的回归方程可预测品种开花期的抗旱性。

[Objective] Rice may suffer serious water stress duringtheir growth period, which affects the process of physiological metabolic activitys. So scientists studied physiological and biochemical characteristics of drought tolerance in rice.. [Method] Ten rice cultivars with different drought tolerances were used as experimental materials. Changes in ascorbic acid （Vc） content, free amino acid content, soluble protein content, malondialdehyde （MDA） content and antioxidative enzyme activities were studied under both irrigation and drought conditions at the flowering stage. [Result] The results indicated that water stress increased contents of Vc, free amino acid, soluble protein and malondialdehyde （MDA）, as well as the activities of superoxide dismutase （SOD）, catalase （CAT） and peroxidase （POD） in leaves at the flowering stage. Correlation analysis showed that the drought tolerant coefficient significantly or very significantly correlated with relative contents of Vc, free amino acid, MDA and SOD activity under both irrigation and drought conditions. [Conclusion] Therefore, they could be selected as identification indexes for drought tolerance at flowering stage. Using stepwise regression equation to evaluate the drought tolerance of rice cultivars was considered scientifically reliable.