摘要
[目的]明确新发现的福建省龙岩市武平县仙草(Mesona chinensis)细菌性枯萎病的病原,为该病害的有效防控提供依据。[方法]采用平板分离法对采集的病株进行病原菌分离、纯化,通过柯赫氏法则验证其致病性。通过常规的生物学特性、特异性引物扩增及16S rDNA序列分析,鉴定病原菌的分类。[结果]从病茎上分离纯化获得8株细菌菌株,接种到健康的仙草后所表现的发病症状与田间采集的症状相类似,且重新分离到与原菌落形态相同的细菌。柯赫氏法则证实,8株细菌菌株均为该病的致病菌。在NA培养基平板上细菌菌落为乳白色,在TTC培养基平板上菌落为暗红色,产生可扩散至培养基中的红褐色色素;细菌革兰氏染色阴性,菌体短杆状,两端圆,1~2根极生鞭毛;菌株可积累聚-β-羟基丁酸盐(PHB),41℃不生长,果胶酶、氧化酶和硝酸盐还原等为阳性;菌株均可利用3种双糖(乳糖、麦芽糖、纤维二糖)和3种己醇(甘露醇、山梨醇、甜醇);用青枯菌演化型复合引物扩增分别获得280、144 bp的目的条带,16S rDNA基因序列分析结果显示,菌株与Ralstonia pseudosolanacearum聚在一支。鉴于此,将分离获得的8株细菌菌株鉴定为假茄科雷尔氏菌(R.pseudosolancearum)。[结论]引起福建省龙岩市武平县仙草细菌性枯萎病的病原菌为假茄科雷尔氏菌,生化型Ⅲ和演化型Ⅰ(亚洲组)。
[Purpose]The pathogenic agent of a new bacterial wilt disease on grass jelly(Mesona chinensis)in Wuping County,Longyan City of Fujian Province,was identified to provide a theoretical basis for the effective control.[Method]The bacterial strains were isolated from the diseased stems of grass jelly by streak plate method,and then tested for pathogenicity via Koch's postulates.The etiological bacterium was identified by biological characteristics,specific primer detection,and 16 S rDNA gene sequence analysis.[Result]The results showed that after inoculated with the 8 strains isolated from the diseased plants,healthy grass jelly seedlings demonstrated the similar symptoms as the specimen collected from the fields;and the bacteria also had an identical colonial morphology when once again isolated from the diseased plants,implying that the 8 strains were identified as the pathogens of grass jelly wilt based on Koch′s postulates.The bacterial colony was milky whitish on NA medium and dark red on tripheny tetrazolium chloride(TTC)medium plate,and red-brown pigments could be further diffused into the TTC medium.These strains were negative Gram-stained,rod-shaped and had 1-2 polar flagella;they accumulated poly-β-hydroxybutyrate(PHB)while stopped growing at 41℃.Meanwhile,they had activities of pectinase,oxidase and nitrate reduction,and can utilize 3 types of disacharides(lactose,maltose and cellobiose)and 3 types of hexanol(mannitol,sorbitol and dulcitol).Two bands,at the size of 280 and 144 bp,were further amplified using composite primers specific for the evolutionary analysis of Ralstonia.Sequencing analysis based on 16 S rDNA showed that these strains were clustered with Ralstonica pseudosolanacearum,indicating that the 8 strains were etiologically identified as R.pseudosolancearum.[Conclusion]The new bacterial wilt disease on grass jelly in Wuping County of Longyan City was caused by R.pseudosolancearum,which belonged to biovar Ⅲ and phylotype Ⅰ(Asia group).
作者
吴水良
林可竟
张一帆
詹梦琳
胡方平
蔡学清
WU Shuiliang;LIN Kejing;ZHANG Yifan;ZHAN Menglin;HU Fangping;CAI Xueqing(College of Plant Protection,Fujian Agriculture and Forestry University,Fuzhou,Fujian 350002,China)
出处
《亚热带农业研究》
2022年第4期267-273,共7页
Subtropical Agriculture Research
基金
福建省引导性项目(2022N0004)
福建省科技特派员工作经费(KTP19128A,KTP21267A)。
关键词
细菌性枯萎病
仙草
假茄科雷尔氏菌
病原鉴定
16S
rDNA
bacterial wilt disease
Mesona chinensis
Ralstonia pseudosolancearum
etiological identification
16S rDNA
