拮抗放线菌2-1-2F的鉴定及其对黄瓜枯萎病的防效OA北大核心CSTPCD

In order to obtain biocontrol actinomycetes to control cucumber Fusarium wilt,a strain 2-1-2F with strong antagonistic activity against F.oxysporum f.sp.cucumerinum(FOC)was isolated from vegetable rhizospheric soil by gradient dilution and confrontation culture methods.Strain 2-1-2F was identified as Streptomyces virginiae by morphology observation and molecular biology identification.It could produce proteases,chitinases and β-glucanases,but not produce siderophores and cellulases.The activity of fermentation liquid produced by 2-1-2F was susceptible to environmental conditions.Fermentation liquid of 2-1-2F had obvious growth-promoting effect on cucumber plants,and could induce the cucumber defense enzyme activities and resistance related substance contents,which reached the maximum value from one to seven days after treatment.Strain 2-1-2F had strong colonization ability in cucumber roots,and the concentration of colonization could still reach 106 cfu/g soil after 42 days.The preventive and therapeutic effects of 2-1-2F on cucumber Fusarium wilt were 48.98%and 34.01%,respectively.Actinomycetes 2-1-2F and its metabolites had the potential to be developed into biocontrol agents.