The Effect of Drought Stress on Photosynthetic Physiological Characteristics of the Different Tobacco Varieties

In order to understand the photosynthetic physiological characteristics differences of various flue-cured tobacco varieties under drought stress,a pot experiment was conducted to determine the effects of mild and severe drought stress on the photosynthetic physiological indices of five flue-cured tobacco varieties: Jiucaiping 2,Qianxi 1,Bina 1,Yunyan87,Yunyan 97 and the relationship with the drought resistance as well.The results showed that,in severe drought treatment,on average,the net photosynthetic rate of five tobacco varieties dropped 48.5%,intercellular CO2 concentration increased 80.9%,transpiration rate decreased 33.6%,stomatal conductance decreased 72.7%.The photosynthetic rate of variety Qianxi 1 and Yunyan 97 decreased less than those of the others,which demonstrated relatively high drought tolerance.