Effects of Water Stress on Soluble Protein and Free Proline Content of Different Boll Weight Genotypes in Cotton

The waterproof installations were carried out to deal with the content of soluble protein and free proline of different boll weight genotypes and inner positions in cotton under water stress.The results showed that the content of soluble protein at different positions appeared different trends for these genotypes under the two treatments,it illustrate that different position had different capacities of adaptation to drought stress.Under water stress,the soluble protein content which in each positions were decreased in these genotypes at the whole stage,the big-boll and small-boll varieties in lower branch leaves showed less accumulation of soluble protein content,the change of the content of soluble content in middle branch leaves was smaller than the lower one for each genotype which showed that the physiological characters of the branch leaves was more stable in the boll development.Under drought stress,the free proline content at each branch leaves showed more accumulation than the CK,the big-boll variety had more accumulation of the content of free proline in each poison.The free proline content in the lower branch leaves was the most,and then the middle ones,the upper ones was the least.Different varieties had different regulation mechanism in the condition of drought,so free proline can be considered as a physiological index nearly correlative to drought of cotton.