苏铁羽叶褐斑病病原菌鉴定及其化学防治药剂的筛选  

Identification of Pathogen Causing Brown Spot in Leaves of Cycas and Its Chemical Control Agent Screening

作　　者：覃茜[1] 丁丽琼 池昭锦[1] 陆祖正[1] 单彬[1] 谢振兴[1] 黄歆怡 许恬 QIN Qian;DING Liqiong;CHI Zhaojin;LU Zuzheng;SHAN Bin;XIE Zhenxing;HUANG Xinyi;XU Tian(Guangxi Subtropical Crops Research Institute,Nanning,Guangxi 530001,China;Nanning Botanical Garden,Nanning,Guangxi 530029,China)

机构地区：[1]广西壮族自治区亚热带作物研究所,广西南宁530001 [2]南宁植物园,广西南宁530029

出　　处：《热带作物学报》2024年第8期1677-1684,共8页Chinese Journal of Tropical Crops

基　　金：南宁植物园横向项目业务费专项(No.2020QXS-YLB-FW01);广西农业科学院基本科研业务专项(桂农科2021YT152)。

摘　　要：本研究旨在分离并鉴定造成苏铁属植物羽叶褐斑病的病原真菌,筛选出对该病原真菌具有强烈抑制作用的化学防治药剂,为苏铁的保护提供理论依据。首先,通过病斑组织分离、纯化后回接滇南苏铁叶片,根据科赫氏法完成其致病性验证。其次,对其进行形态鉴定;再应用SSU、LSU、GAPDH、tef1、rpb2、Alt、OPA10-2、ITS 8个基因序列,构建多基因进化树进一步鉴定病原真菌。最后,通过平板抑菌试验,从7种化学药剂中筛选出高效的抗菌药剂。本研究发现,形态学鉴定与多基因联合进化分析表明,该病原菌为链格孢属的巴斯基链格孢(Alternariaburnsii);在7种化学药剂平板抑菌试验中,氟酰羟·苯甲唑效果最佳,其浓度在0.67 mg/L时抑菌率达到73.48%。This research aimed to identify a pathogenic fungus of the brown spot disease in the leaves of Cycas and screen for its chemical control agents,which provides a theoretical basis for the protection of Cycas.The pathogenic fungus was isolated from the lesion spots in some Cycas leaves.The pathogenicity of the fungus was confirmed by iso-lating and purifying the infected leaf tissues and reintroduced to the healthy leaves of Cycas diannanensis following Koch’s postulates.Morphological identification of the pathogenic fungus was conducted.To further confirm the identi-fication,a phylogenetic tree was constructed using eight gene sequences:SSU,LSU,GAPDH,tef1,rpb2,Alt,OPA10-2 and ITS.Effective chemical control agents were screened from seven chemical agents by inhibition assay in vitro.Phy-logenetic analyses showed that this pathogen was Alternaria burnsii.Among the tested chemical agents,the most effec-tive inhibition was fluoxastrobin,which displayed 73.48%inhibition rate at a concentration of 0.67 mg/L.

关 键 词：苏铁 褐斑病 病原鉴定 巴斯基链格孢 平板抑菌试验 

分 类 号：S432.44[农业科学—植物病理学]