Effects of Low Temperature Stress on Photosynthetic Characteristics and Chlorophyll Fluorescence Parameters of Eggplant Seedlings

Taking the eggplant parthenocarpy(D-11)and non-parthenocarpy(00-13)seedlings of different cold tolerance as materials,low temperature(5 ℃)stress was treated in the artificial climate chamber,and the effects of low temperature on photosynthetic characteristics and chlorophyll fluorescent parameters of eggplant seedlings were studied.The results showed that the net photosynthetic rate was decreased,the intercellular CO2 concentration was increased in the former stage(before 2 days)then decreased(after 2 days),the transpiration rate and stomatal conductance were decreased first and then increased in leaves of eggplant seedlings with the prolongation of the low temperature stress time.The maximal photochemical efficiency,photosynthetic electron transport rate,photochemical quenching coefficient were generally decreased,and non photochemical quenching coefficient in leaves of eggplant seedlings was increased slowly.It suggested that the proportion of the light energy absorbed by leaf of parthenocarpy material for efficient electron transfer was higher,and photosynthesis of that was inhibited to a lesser degree.The electron transfer rate of poor tolerance material was decreased significantly,excess excitation energy of that was higher,photosynthetic activity was more serious damaged,and photosynthetic capacity was decreased greatly.