Change of Rewatering after Long-Term Drought Stress on Photosynthesis and Content of Carbon and Nitrogen of Cotton

In order to study the changes of rewatering after long-term drought stress on cotton,we used up-land cultivar Xinluzao 45 as the materials to measure the photosynthetic capacity,specific leaf weight and carbon-nitrogen ratio(C/N)in developing leaves.The results showed that the net photosynthetic rate,stomatal conductance and leaf area of developing leaves increase undergoing rewatering after long-term drought stress,the content of chlorophyll and nitrogen also increased to varying degrees.The content of nitrogen in the developing leaves after rewatering increased,and the time of C/N ratio also rose earlier. Our results indicated that the photosynthetic characteristics of leaves changed undergoing rewatering after long-term drought stress.The higher content of chlorophyll,nitrogen,and stomatal conductance could provide basic conditions for the higher net photosynthetic rate.The time of C/N ratio rising earlier in developing leave after rewatering probably suggested that the photoassimilate of cotton inclined to reproductive growth after rewatering.