不同水、氮条件下水稻不同叶位水、氮含量及光合速率的变化特征

本文研究了不同土壤水氮条件下，水稻不同叶位含水率、含氮率、叶色和光合速率的动态变化特征。结果表明，拔节至抽穗前后，不同叶位含水率为顶1叶<顶2叶<顶3叶<顶4叶；随胁迫时间的推移，灌浆期后不同叶位水分变化趋势随水分处理而异，W3和W5同拔节至抽穗期，而W1和W2表现相反（W1至W5为由低到高土壤水分处理）。不同叶位叶

Variation of Water and Nitrogen Contents & Photosynthesis at Different Position Leaves of Rice under Different Soil Water and Nitrogen Conditions

Water content, nitrogen content, leaf color and photosynthesis of each functional leaf on main stem of rice under different soil water and nitrogen conditions were investigated. Results showed that the distributions of leaf water contents on main stem in all treatments were L1> before heading, but after heading, the trends were L1> in W3 and W5. For leaf photosynthesis, the trends were L1>2>L3>L4 in all treatments. Distribution trends of leaf nitrogen contents on main stem were the same as that of the leaf color under high and low soil nitrogen conditions. Under adequate soil water supply photosynthesis was negatively linearly related to leaf water content, and positively linearly related to leaf nitrogen content and leaf color values, but negatively linearly related to leaf water content, nitrogen content and leaf color values under soil water stress. In addition, the ratios or differences of water content, nitrogen content & photosynthesis in different position leaves were significantly related to the leaf water con tent, N content and photosynthesis in canopy respectively.