【摘要】 为比较不同形态氮素营养下籼稻与粳稻对水分胁迫的响应,采用室内营养液培养,通过供应不同形态氮素及100g/LPEG6000模拟水分胁迫的方法,对4种不同基因型水稻的生长状况及渗透调节能力进行了分析。结果表明:1)与铵态氮营养相比,水分胁迫明显抑制了硝态氮营养籼稻和粳稻的地上部生长,降低了叶片净光合速率,且对粳稻的抑制效果更加显著;2)水分胁迫条件下,铵态氮营养籼稻和粳稻植株内的游离氨基酸和K+可以更有效地积累、转运和穿梭,以致伤流液和韧皮部汁液拥有更强的渗透调节能力;3)铵态氮营养籼稻和粳稻在通过渗透调节降低叶片渗透势的同时,能够提高或维持叶片含水量。由此可见,铵态氮营养下,籼稻和粳稻均可通过渗透调节促使叶片在渗透势下降和维持含水量之间达到合理的平衡,保证叶片在水分胁迫下维持正常的光合速率,提高了水稻的抗旱能力。更多还原

【Abstract】 The responses of indica and japonica rice seedlings to water stress were studied by supplying with different nitrogen forms under 100 g/L PEG6000 simulated water stress.The results showed that compared with ammonium nutrition,water stress significantly decreased shoot growth and photosynthesis of nitrate supplied indica and japonica rice seedlings with a more severe inhibition on japonica rice seedlings;under water stress,ammonium supplied rice plants could sufficiently accumulate and transfer amino acids and potassium,which led to relative higher amino acids and potassium contents in xylem and phloem sap;when leaf water potential decreased under water stress,ammonium supplied rice plants could enhance or maintain relative higher leaf water content through osmotic regulation.Therefore,when leaf water potential was decreased under water stress,the maintenance of leaf water content in ammonium supplied rice plants ensured relative higher photosynthesis,which subsequently enhanced the tolerance of rice plants to water stress.更多还原