Effects of Root Zone Temperature on Physiological Characteristics of Pepper Seedlings

To probe into the sunlight greenhouse soil temperature in the winter stress on crop water content,protective enzymes,osmolyte and membrane permeability in pepper,we comparatively studied three treatment( 20-22,14- 16,10- 12 ℃),the water contents of seedling stems and roots,the activities of super oxede-dismutase( SOD),peroxidase( POD),catalase( CAT),proline( Pro),malondialdehyde( MDA) and electrolytic permeability contents were determined by using Changjin,Xunchi 37- 74 and Yunchi 37- 82 in pepper. The results showed that as the root zone temperature dropped the seedling water content appeared the tendency of decline,among water content was the lowest in 10- 12 ℃ treatment. The activities of SOD,POD and CAT in leaf appeared the trend of decline. The contents of Pro,MDA and electrolytic perme ability appeared the trend of rising. In a word,10- 12 ℃treatment on influencing degree of water content,physiological and biochemical characteristics in pepper seedlings was significantly higher than 20- 22,14- 16 ℃ treatments. Taking physiological and biochemical characteristics as measurement index,we concluded that pepper could still keep its normal growth and development when the root zone temperature over 14 ℃.