一种新发大豆根腐病的病原鉴定及防治药剂筛选  

Pathogen identification and control fungicide screening of a novel soybean root rot

作　　者：黄智星 李月 丁洁欣 林海蔚 程艳波[2] 年海[2] 周而勋[1] HUANG Zhixing;LI Yue;DING Jiexin;LIN Haiwei;CHENG Yanbo;NIAN Hai;ZHOU Erxun(College of Plant Protection/Guangdong Province Key Laboratory of Microbial Signals and Disease Control,South China Agricultural University,Guangzhou 510642,China;College of Agriculture,South China Agricultural University,Guangzhou 510642,China)

机构地区：[1]华南农业大学植物保护学院/广东省微生物信号与作物病害防控重点实验室,广州510642 [2]华南农业大学农学院,广州510642

出　　处：《华中农业大学学报》2024年第6期229-239,共11页Journal of Huazhong Agricultural University

基　　金：广东省重点领域研发计划项目(2020B020220008)。

摘　　要：为明确在广东新发现的一种大豆根腐病的病原菌种类,了解其生物学特性,筛选防治该病的有效杀菌剂,采用组织分离法对罹病大豆植株的根部和茎基部的病原真菌进行分离,并通过形态学和3个基因(rDNA-ITS,TEF-1α,RPB2)的联合系统发育分析对病原真菌进行鉴定,再将该病原真菌接种到原发病大豆品种桂夏2号的根部和茎基部,测定其致病性和不同培养基、温度、碳氮源、pH、光照、杀菌剂对菌丝生长的影响以及病原菌分生孢子的致死温度。结果显示,分离到2株具有不同特征的真菌,分别鉴定为新孢镰刀菌(Fusarium neocos-mosporiellum)和镰状镰刀菌(F.falciforme),后者是在我国广东大豆上的首次报道;接种试验显示,这2株真菌单独或混合接种均可引起与田间自然发生的大豆根腐病相似的症状;新孢镰刀菌(F.neocosmosporiellum)在28℃、pH 7条件下生长最快,可以有效利用多种碳氮源,乳糖和蛋白胨为最佳碳氮源,分生孢子致死温度为51℃(水浴10 min);镰状镰刀菌(F.falciforme)在25℃、pH 7条件下生长最快,碳氮源利用能力强,以乳糖、蔗糖和麦芽糖为最佳碳源,最佳氮源为蛋白胨,孢子致死温度为54℃(水浴10 min);不同光照处理对2个菌株的菌丝生长无影响;杀菌剂咪鲜胺对2个菌株的抑制作用最强。综上,引起广东新发大豆根腐病的病原真菌为新孢镰刀菌(F.neocosmosporiellum)和镰状镰刀菌(F.falciforme),而这2种真菌适应环境的能力强,对咪鲜胺敏感,该药剂可作为防治新发大豆根腐病的首选药剂。In order to identify the species of pathogenic fungi responsible for a novel soybean root rot in Guangdong,understand their biological characteristics,and screen effective fungicides to control the disease,the pathogenic fungi were isolated from the roots and stem bases of infected soybean plants using a tissue isolation method.The fungi were identified based on their morphology and through a combined phylogenetic analysis of 3 genes(rDNA-ITS,TEF-1α,and RPB2).Subsequently,the isolated pathogenic fungi were inoculated into the roots and stem bases of the original soybean cultivar Guixia No.2,either alone or in combination,to determine their pathogenicity.The effects of various media,temperatures,carbon and nitrogen sources,pH,light and fungicides on mycelial growth,as well as the lethal temperatures of the pathogens’conidia were measured.The results showed that two fungal strains with different characteristics were isolated from the roots and stem bases of infected soybean plants,identified as Fusarium neocosmos-poriellum and F.falciforme,respectively.The later was first reported in soybeans in Guangdong,China.Inoculation experiments showed that both fungal strains,whether individually or in combination,could cause symptoms similar to those of soybean root rot disease observed in the field.F.neocosmosporiellum exhibited the fastest growth at 28˚C and pH 7,effectively using a variety of carbon and nitrogen sources,with lactose and peptone identified as the most effective carbon and nitrogen sources,respectively.The lethal temperature for conida was 51˚C for 10 min.In contrast,F.falciforme showed the highest growth rate at 25˚C and pH 7,with a strong capacity for using carbon and nitrogen sources.Lactose,sucrose,and maltose were the most effective carbon sources,while peptone was the optimal nitrogen source.The lethal temperature for conidia was 54˚C for 10 min.Different light treatments did not affect the mycelial growth of either strain.The fungicide prochloraz exhibited the strongest inhibitory effect on b

关 键 词：大豆根腐病 镰刀菌 病原鉴定 生物学特征 多基因系统发育分析 杀菌剂筛选 

分 类 号：S435.651[农业科学—农业昆虫与害虫防治]