Studies onphysiological mechanism of eggplant under low temperature stress

Effects of low temperature stress on the chilling index,the growth and physiological indexes of five eggplant seedlings with differentlow temperature resistance were studied.The results showed that(l)all the biomass production(plant height,stem diameter and shoot fresh weight)of five materials were significantly inhibited under low temperature stress,and the inhibition degree of low temperature resistant materials were less than that of low temperature sensitive materials;(2)contents of malondialdehyde(MDA)and O_2·~-producing rate,activities of superoxide dismutase(SOD)and peroxidase(POD),contents of proline and soluble protein in the leaves were significantly increased;the MDA content and O_2·~- production rate of low temperature resistant materials increased less than that of low temperature sensitive materials,the SOD and POD activities increased more than that of low temperature sensitive materials;the content of proline and soluble protein increased irregularly;(3)the chilling index of eggplants were significant negative correlation with the decrease ratio of stem diameter and shoot fresh weight,contents of chl,SOD and POD activities;the chilling index of eggplants were significant positive correlation with contents of MDA and O_2·~- producing rate;the chilling index of eggplants were not significant with the decrease ratio of plant height,contents of proline and soluble protein.The above results showed that the growth of eggplant seedlings were inhibited under low temperature stress,but the low temperature resistant materials could regulate the activity of enzyme system to alleviate the damage of low temperature stress and maintain normal growth and physiological metabolism in plants.