【摘要】 甘蔗白条病是由白条黄单胞菌Xanthomonas albilineans(Ashby) Dowson引起的甘蔗重要病害。2017年在云南保山、孟定和金平蔗区的甘蔗上发现疑似白条病的病害。从病株蔗茎中分离得到圆形,凸面,光滑,有光泽,黄色的细菌菌落。经柯赫氏法则验证,分离得到的细菌为该病害的病原菌。使用16S rRNA基因、gyrB基因和rpoD基因对分离得到的病原菌进行了分子鉴定,BLAST和系统发育分析表明本研究所获得的病原菌的3个基因的核苷酸序列与白条黄单胞菌GPE PC73菌株(GenBank登录号:FP565176)对应基因的核苷酸序列一致性均为100%,在系统发育树中处于同一分支。根据田间症状诊断、柯赫氏法则验证及分子鉴定结果,确认云南保山、孟定和金平发生的甘蔗病害为X.albilineans引起的甘蔗白条病。更多还原

【Abstract】 Leaf scald caused by Xanthomonas albilineans(Ashby) Dowson is an important disease of sugarcane. In 2017, suspected sugarcane leaf scald was found in Baoshan, Mengding and Jinping of Yunnan Province. Circular, convex, smooth, shiny, yellow pigmented bacterial colonies were isolated from symptomatic stalks. The result of Koch’s postulates showed that the isolated bacteria were the causal agent of the disease. Molecular identification of pathogenic bacteria was carried out based on 16 S rRNA gene, gyrB gene and rpoD gene. BLAST analysis showed that the amplified nucleotide sequences of three genes shared 100% sequence identity with that of corresponding genes of X. albilineans strain GPE PC73(accession no. FP565176). Phylogenetic analysis showed that all isolates in this study and X. albilineans were clustered together into one branch. Base on the result of symptom diagnosis in the field, validation of Koch’s postulates and molecular identification, the sugarcane disease occurred in Baoshan, Mengding and Jinping was confirmed to be leaf scald caused by X. albilineans.更多还原