Abstract:

In order to look for new resources of biocontrol on tomato gray mould and explore biocontrol mechanism of plant endophytic actinomyces, antagonistic screening of tomato endophytic actinomyces and activities of its metabolites were studied. Nine endophytic actinomyces were isolated from healthy tomatoes. Antagonistic strain against Botrytis cinerea Pers. was screened out through dual-culture and inhibitory activity test. Bioactivities of metabolites on promoting growth, induced resistance and disease control were studied through growth of tomato seeds and seedlings, changes of resistant enzymes, and pot test. The results were as follows. (1) Inhibit radius of strain Fq24 against B. cinerea was above 10 mm. Antagonistic effect of fermentation solution reached 68.4%. (2)Fermentation solution could promote growth of root and stem in middle concentration. Dry weight, fresh weight and height respectively increased by 168.35%, 128.57% and 70.79% in seedlings. (3)Activities of superoxide dismutase (SOD) and peroxidease (POD) in tomato plants treated with Fq24 fermentation solution obviously increased. The largest increasing change rates of POD and SOD activities were 71.3% and 62.3%. (4)Spraying Fq24 fermentation solution could significantly reduce tomato gray mould occurrence, attain the obvious control effect reaching 88.14%. Fq24 was an antagonistic strain, whose metabolites could significantly promote tomato seeds germination and seedlings growth, induce POD and SOD activities to improve, significantly reduce disease occurrence, and attain the obvious control effect.