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为获得用于防治柑橘采后病害的海洋放线菌,以柑橘青霉病菌Penicillium italicum、柑橘绿霉病菌P.digitatum和柑橘炭疽病菌Colletotrichum gloeosporioides为指示菌,对分离到的25株海洋放线菌进行筛选。通过平板对峙法测定拮抗菌株的抑菌谱,并测定其发酵产物粗提物对柑橘果实采后病害的防效,根据形态特征、培养特征、生理生化特征及16S rDNA序列对其进行鉴定。结果表明,分离自鳞笠藤壶Tetraclita squamosa的菌株A3202对3种指示菌均具有强抑菌活性,对供试13种植物病原菌的菌丝生长具有不同程度的抑制作用,尤其对柑橘青霉病菌和柑橘绿霉病菌的抑制作用最强,抑菌带宽度分别可达2.33±0.05cm和2.32±0.10cm。该菌株800mg/L粗提物溶液对接种后7 d的柑橘青霉病、柑橘绿霉病和柑橘炭疽病的相对防效均可达100%。初步鉴定该菌株为放线菌中的米修链霉菌Streptomyces misionensis。
In order to obtain marine actinomycetes for the prevention and treatment of postharvest citrus diseases, Penicillium italicum, P.digitatum and Colletotrichum gloeosporioides were used as indicator bacteria to isolate 25 marine actinomycetes Screening. The antibacterial spectrum of the antagonistic strains was determined by plate confrontation method. The antifungal activity of crude extracts of the fermented products was evaluated. The morphological, culturing characteristics, physiological and biochemical characteristics and 16S rDNA sequence of the crude extracts were determined. The results showed that the strain A3202 isolated from Tetraclita squamosa had strong antimicrobial activity against three kinds of indicator bacteria and had different degrees of inhibition on mycelial growth of 13 plant pathogens tested, especially against Penicillium citrinum And Citrobacter rubrum most inhibitory effect, inhibitory zone width of up to 2.33 ± 0.05cm and 2.32 ± 0.10cm. The relative control efficiency of the 800mg / L crude extract solution against citrus green mold, citrus green mold and citrus anthracnose on the 7th day after inoculation was up to 100%. The preliminary identification of this strain is Streptomyces misionensis in actinomycetes.