Effects of Exogenous Melatonin on Growth and Physiological Characteristics of Leaves in Shepherd's-purse Seeding under NaCl Stress

The effects of exogenous melatonin on growth and physiological characteristics of Shepherd's-purse seedlings under salt Stress were studied by spraying 5 different concentrations of MT (0, 50, 100, 150, 200 mu mol.L-1) solution on leaves in Shepherd's-purse seedlings. The result showed that spraying MT on leaves in Shepherd's-purse seedlings which plant height. root length. fresh and dry weight were higher than control. With the increase of concentration of MT, the general tends of chlorophyll and carotenoid content on leaves in Shepherd's-purse seedlings were all first increased then decreased together. Besides, spraying MT not only strengthened the activity of anti-oxygenic enzyme and enhanced anti-oxygenic ability, but also restrained MDA accumulation and increased soluble protein content. Therefore, exogenous MT could efficiently enhance resistance to salt stress, and the 150 mu mol.L-1 was the best concentration.