Research on Influence of Drought Stress on Photosynthetic Characteristics of Flue-cured Tobacco

The potted flue-cured tobacco varieties Yunyan 87 and K326 were used as test materials,drought stress treatments for different time( 0 ~ 16 d) were conducted respectively at their resetting stage,vigorous growing stage and squaring stage,and the influence of drought stress on the photosynthetic characteristics of flue-cured tobacco was studied. When drought stress time prolonged,the stomatal conductance,transpiration rate,and net photosynthetic rate of two varieties all showed a decreased tendency,while their intercellular CO2concentration decreased significantly and then increased slightly. As drought treatment time increased,the chlorophyll content in Yunyan 87 revealed a declining trend,while that in K326 reduced first and then rose. After being influenced by drought stress,Yunyan 87 had a slightly better general performance in photosynthetic characteristics than K326.