奉新猕猴桃黑斑病病原菌鉴定及室内药剂筛选  

Identification of Pathogen Causing Kiwifruit Black Spot in Fengxin County and Screening of Controlling Fungicides in Laboratory

作　　者：周英[1] 李庚花[1] 胡叶开 强遥 张凯东 赵尚高 李帮明 蒋军喜[1] ZHOU Ying;LI Geng-hua;HU Ye-kai;QIANG Yao;ZHANG Kai-dong;ZHAO Shang-gao;LI Bang-ming;JIANG Jun-xi(College of Agronomy,Jiangxi Agricultural University,Nanchang 330045,China;Yaoli Agricultural Technology Station,Fuliang County,Fuliang,Jiangxi 333411,China;Agricultural Bureau of Fengxin County,Fengxin,Jiangxi 330700,China)

机构地区：[1]江西农业大学农学院,江西南昌330045 [2]江西省浮梁县瑶里农技站,江西浮梁333411 [3]江西省奉新县农业局,江西奉新330700

出　　处：《江西农业大学学报》2020年第1期48-56,共9页Acta Agriculturae Universitatis Jiangxiensis

基　　金：国家自然科学基金项目(31460452);江西省科技计划项目(20181ACF60017)~~

摘　　要：【目的】明确江西省奉新县猕猴桃黑斑病病原菌种类,筛选防治该病害的有效药剂。【方法】从奉新县果园中随机采集40个呈典型症状的猕猴桃黑斑病病果,采用PDA培养基按照常规组织分离法对其进行病菌分离和纯化。从获得的菌株中选择代表性菌株HB-1进行病菌鉴定和药剂筛选。在测定其致病性的基础上对其培养性状、分生孢子和分生孢子链形态进行观察,并测量其分生孢子大小。根据菌落形态特征和病菌形态大小,参考相关文献,对病原菌进行种类归属鉴定。提取菌株HB-1基因组DNA,对其rDNA-ITS和EF-1α基因进行PCR扩增和序列测定,根据序列同源性大小对病原菌进行分子鉴定。采用菌丝生长速率法测定22种杀菌剂对该病菌的室内抑菌活性。【结果】共分离获得35个培养性状一致的真菌菌株,供试菌株HB-1具有致病性,其菌落绒状,正面墨绿色,背面淡绿色。菌株产生卵形或倒棍棒形,具2~5个横隔膜和1~3个纵、斜隔膜、大小(15~50)μm×(7.5~12.5)μm的分生孢子。分生孢子链状着生并有分支,支链一般长1~5个孢子,最长也未达到10个孢子。上述培养性状和形态特征符合文献中对链格孢(Alternaria alternata)的描述。该菌株的rDNA-ITS和EF-1α基因序列长度分别为531 bp和240 bp,与GenBank中链格孢(A.alternata)的序列同源性为100%。在药剂筛选试验中,申嗪霉素、咪鲜胺锰盐、己唑醇、肟菌·戊唑醇、丙环唑、苯醚甲环唑、戊唑·嘧菌酯和氟硅䂳8种杀菌剂抑菌活性强,EC50值均小于1μg/mL;中生菌素、嘧菌环胺、吡唑醚菌酯、异菌脲、噁酮·锰锌、多抗霉素、丙森锌、代森联和腈苯唑9种杀菌剂抑菌活性较强,EC50值1~10μg/mL;啶酰菌胺、乙蒜素、春雷霉素、精甲·百菌清和百菌清5种杀菌剂的抑菌活性较弱或不明显,EC50值均大于25μg/mL。【结论】确定奉新县猕猴桃黑斑病病原为链格孢(A.alternata),申嗪霉�[Objective]The objective of this study is to identify the pathogen of kiwifruit black spot in Fengxi County of Jiangxi Province and screen out effective fungicides for control of the disease.[Method]A to⁃tal of 40 diseased fruit samples showing typical symptoms of kiwifruit black spot were randomly collected from orchards in Fengxin County.The pathogenic fungus was isolated and purified on PDA medium from the samples using normal tissue isolation method.The representative strain HB-1 was selected from the obtained strains for pathgen identification and fungicide screening.After completion of pathogenicity test,their culture characters,morphology of the conidia and their chains were observed,and the size of the conidia was measured.The patho⁃gen species was identified based on comparing its cultural and morphological characters with corresponding de⁃scription in related literature.Genomic DNA of strain HB-1 was extracted and used as a template to amplify the rDNA-ITS and EF-1αgene by PCR,and the PCR products were directly sequenced.Molecular identification of the pathoen was conducted based on the nucleotide sequence homology.The inhibition activity of 22 fungicides against the pathogen was determined by mycelial growth rate method[.Result]Totally 35 fungal strains with the same cultural characteristics were obtained.The test strain HB-1 had pathogenicity.Its colonies were fluffy,and dark green on the front side and light green on the back side.It produced oval or obclavate conidia with size of 15-50μm×7.5-12.5μm.Each conidium contained 2-5 transverse septa and 1-3 longitudinal/oblique septa.The conidia were in chains and had branches.The branch chain was usually 1-5 spores long,and the longest co⁃nidia chain did not reach 10 spores.The above culture characters and morphological characteristics are consis⁃tent with the description of Alternaria alternata in the literature.The rDNA-ITS and EF-1αgenes of HB-1 were 531 bp and 240 bp in length respectively,which shared 100%homology with A.alternata in G

关 键 词：猕猴桃黑斑病 链格孢 杀菌剂 毒力测定 

分 类 号：S436.634.12[农业科学—农业昆虫与害虫防治]