Effects of Five Allelochemicals on the Seedling Growth and the Antioxidant Enzymes Activities of Pogostemon cablin

Key words: 
• Pogostemon cablin /
• allelochemicals /
• antioxidant enzymes

Abstract: Pogostemon cablin seedlings were watered with 5 allelochemicals（ benzoic acid,vanillic acid,salicylic acid,p-hydroxy benzoic acid and malonic acid） at the concentration of 0. 5,1. 0,5. 0,10. 0 mmol·L^-1,respectively to observe their growth,and their activities of superoxide disproportionation enzyme（ SOD）,peroxidase（ POD） and membrane lipid peroxidation products（ MDA）. The results showed that these 5 allelochemicals had obvious effects on the growth of P. cablin seedlings,and tended to promote the plant growth at a low concentration and suppress plant growth at a high concentration. The membrane permeability,MDA content and POD activities were obviously increased with the concentration of the allelochemicals,but the SOD activities were first increased at a lower concentration and then decreased at a higher concentration. The growth of P. cablin seedling depended on both allelochemicals and their concentrations. The growth and development of P. cablin was restrained obviously in the treatment of p-hydroxy benzoic acid at a concentration of 10. 0 mmol·L^-1.