Effects of Tobacco Root Exudates on the Growth and Enzymes Activities of Fire-cured Tobacco Seedling

The effects of different concentration flue-cured tobacco root exudates on the growth of flue-cured tobacco seedlings, dry matter accumulation, chlorophyll content, root activities and enzyme activities of tobacco were studied. Results showed that with the increase of root exudates concentration, seedling height, the maximum leaf length, the maximum leaf width, the total root surface area, the number of branches, the root average diameter, the number of root tip, the content of chlorophyll A and chlorophyll B, the content of carotenoids and root activity were first stimulated and then inhibited on the whole. The fresh-dry ratio,MDA content performed with the trend of increase. The root-top ratio, activity of SOD and POD performed with the trend of inhibition. The inhibition of higher concentration of flue-cured tobacco root exudates was more obvious.