Effects of sub-low temperature and drought stress on osmotic substances and activities of antioxidant enzymes in tomato seedling

With potted tomato plants in greenhouse as the experiment material,we investigated the influence of sub-low temperature and drought stress on osmotic substances and activities of antioxidant enzymes in tomato seedling.The results showed that with the interaction of sub-low temperature and drought stress treatment time prolong,MDA content、relative membrane conductivity in leaves of tomato seedling increased,soluble protein content and SOD activities first increased and then decreased gradually with the prolong of treatment time.The change of POD activities showed inverted Vpattern and POD activities showed Mpattern,Tomato seedling of sub-low temperature is greater sensitivity than drought stress.The correlation analysis and Principal component analysis indicated that POD、CAT was significantly positively negatively correlated to relative membrane conductivity,positively negatively correlated to MDA content;SOD was related to MDA,POD and CAT was significantly positively related.