Effects of Drought Stress on Chlorophyll Content of Yunyan 87 in Different Growth Periods

The effects of drought stress on the chlorophyll content of Yunyan 87 at different growth stages were studied by pot experiment and water control technique.The results showed that the chlorophyll content of tobacco leaf in different growth periods had a gradual declining trend with the prolonging of drought stress time.In comparison with the control,the treatments of 16-d drought and long-term drought at resettling growth stage decreased the chlorophyll content by 38.62% and 41.27%,respectively;the treatment of 13-d drought at vigorous growing stage decreased that by 47.16%;the treatments of 16-d drought and long-term drought at budding stage decreased that to almost half.After ending drought stress and carrying out normal water management,the content of chlorophyll increased gradually,and its recovery in 7-d drought treatment was the fastest,while the recovery was slow in the treatments of more than 13-d drought.