摘要
为有效防控太子参根腐病,本研究于2017年3月—2019年6月自福建省宁德市柘荣县太子参主产区采集具有典型根腐病症状的植株和块根病样,分离纯化获得病原菌,利用形态学特征、分子生物学特性及致病性测定对其进行鉴定;同时通过测定平板抑制率和扫描电镜观察分析6种杀菌剂对太子参根腐病病原菌菌丝生长的抑制效果。结果表明:太子参根腐病典型症状为苗期和生长期植株萎蔫、根部和茎基部褐变;块根表皮呈现开裂、组织褐变和干腐状。分离纯化后获得22株培养性状一致的菌株,结合菌株的形态学特征、EF-1α基因序列和特异性引物FOF1/FOR1检测,将该病原菌鉴定为尖孢镰刀菌Fusarium oxysporum。致病性测定结果表明其发病症状与田间表现一致,且符合科赫氏法则。经筛选6.6%嘧菌酯·1.1%咯菌腈·3.3%精甲霜灵悬浮种衣剂和25%吡唑醚菌酯乳油对该病原菌有良好的抑制效果,稀释至2000倍液的抑制率分别为78.52%和75.36%;扫描电镜观察显示这2种杀菌剂处理组的菌丝体发育畸形、断裂、表面皱缩或消解,未见产孢细胞;而无菌水对照处理组的菌丝体生长正常,可见产孢细胞。表明筛选到的2种杀菌剂可用于防治由尖孢镰刀菌引起的太子参根腐病。
In order to effectively prevent and control root rot of Pseudostellaria heterophylla,the plants and tuber roots with typical root rot symptoms were collected from the fields in Zherong County,Ningde City,Fujian Province during March 2017 to June 2019.The pathogen was isolated and identified based on morphology,molecular biology and pathogenicity test.The inhibition of six fungicides on the pathogen was evaluated by observing the inhibitory effects on mycelium growth on medium plates and under scanning electron microscope.The results showed that the typical symptoms of root rot on the infected seedlings and growing stages of P.heterophylla plants were wilting,browning at roots and stem bases as well as epidermis cracking,tissue browning and dry rot at tuber roots.Twenty-two isolates were obtained from the diseased samples with the same morphological characteristics.The pathogen was finally identified as Fusarium oxysporum based on morphological characteristics,PCR amplification using specific primers FOF1/FOR1 and sequence analysis of translation elongation factor-1α(EF-1α)gene.Inoculating the pathogen on the healthy plants and tuber roots reproduced the symptoms previously observed in the field.Pathogenicity was confirmed by fulfilling Koch’s postulates.The results of chemical screening showed that 6.6%azoxystrobin·1.1%fludioxonil·3.3%mefenoxam and 25%pyraclostrobin EC exhibited good inhibition effects on the pathogen with an inhibition rate of 78.52%and75.36%,respectively,at 2000×dilution.Scanning electron microscopy observation showed that the two fungicides could cause mycelia abnormal,broken,surface shrinking or loss and sporulation cells invisible.Meanwhile,the mycelia treated with sterile water grew normally and the sporulated cells could be seen.It was recommended that these two fungicides could be used for the control of root rot disease of P.heterophylla.
作者
肖荣凤
陈燕萍
陈梅春
阮传清
朱育菁
刘波
XIAO Rongfeng;CHEN Yanping;CHEN Meichun;RUAN Chuanqing;ZHU Yujing;LIU Bo(Research Institute of Agricultural Biological Resources,Fujian Academy of Agricultural Sciences,Fuzhou 350003,Fujian Province,China)
出处
《植物保护学报》
CAS
CSCD
北大核心
2020年第6期1333-1342,共10页
Journal of Plant Protection
基金
福建省农业科学院对外合作项目(DEC201821206)
科技创新团队项目(STIT2017-1-11)
福建省属公益项目(2018R1017-9)。
关键词
太子参
根腐病
尖孢镰刀菌
鉴定
杀菌剂筛选
Pseudostellaria heterophylla
root rot
Fusarium oxysporum
identification
fungicide screening
