Abstract:

A promising biocontrol agent HL5-4，a strain with strong effect on tomato gray mold，which selected from the rhizosphere of healthy tea plant. In vitro and in vivo experiments were used to determine its antifungal effect and colonization ability. The results showed that，HL5-4 inhibited mycelial growth and conidia germination of Botrytis cinerea in vitro experiment，the inhibition zone of the mycelial growth was 15 mm，the inhibition rate of conidia germination was 70.74%；HL5-4 performed good control potential against tomato gray mold，the control efficiencies were 72.36% and 59.85% respectively on fruits and leaves in vitro experiment，and 62.88% on seedlings in pot；HL5-4 persisted on fruits and leaves of tomato with a relative population density which were more than 10⁴ and 10³ cfu · g^-1 respectively；based on the morphological，physiological characteristics and 16S rDNA sequence analysis，the strain HL5-4 was identified Pseudomonas chlororaphis.

Key words: Pseudomonas chlororaphis, tomato gray mold, antifangal activity, colonization ability