Effect of Amino Acids on Tobacco Alternaria alternata Phytotoxin Virulence

The phytotoxin virulence of tobacco Alternaria alternata was tested with three methods, rubbing inoculating, root watering and seed-bud root treating.The seed-bud root treating was chosen as the testing method. Alternaria alternata (GL-6) mixed separately with 8 kinds of amino acid at 5 different concentrations were inoculated.The results indicated that phytotoxin virulence was heightened by l-arginine, l-cystine, l-glutamic acid, l-alanine, and l-aspartic acid at all tested concentrations.However, the phytotoxin virulence could be depressed by lproline, l-tryptophane and l-valine, the effective concentrations were 0.02-0.2mg/mL, 0.02-0.2mg/mL and 0.02-2mg/mL, respectively.