广西蔗区检测发现检疫性病害甘蔗白条病

Sugarcane Leaf Scald Disease Found in Guangxi Sugarcane Region

为明确2016年在广西北海、来宾、百色蔗区发现的疑似甘蔗白条病症状蔗株致病病原。利用白条黄单胞菌特异性引物XAF1/XAR1对采自这3个蔗区的62份疑似病样进行PCR检测鉴定。鉴定结果表明:62份疑似病样都能够获得约600 bp的特异性片段,所得序列完全一致大小均为608 bp(Gen Bank登录号:KY315183--KY315203),其与白条黄单胞菌rax B1基因核苷酸序列(Gen Bank登录号:FP565176)一致性为100%,在系统进化树中处于同一分支。田间调查结果显示:甘蔗品种‘桂糖46号’、‘桂糖06-2081’对于白条黄单胞菌高度感病,病株率一般为18%~50%,严重田块高达100%;染病严重蔗株全叶枯萎,茎的节部长出许多侧芽,侧芽叶片具白色条纹,造成大幅度减产减糖。本研究在广西蔗区检测发现由白条黄单孢菌引起的检疫性病害甘蔗白条病。

The aim is to identify the pathogen of suspected sugarcane leaf scald plants observed in Beihai,Laibin, and Baise in Guangxi Province in 2016. The PCR detection with the specific primers XAF1/XAR1 of Xanthomonas allbilineans was performed on 62 suspected leaf scald samples collected from the three areas.The identification results showed that the 600 bp specific fragment was amplified in all 62 suspected leaf scald samples, and all nucleotide sequences from this study were identical, 608 bp in length（Gen Bank accession numbers： KY315183-KY315203）, shared 100% sequence identity with the nucleotide sequence of rax B1 gene of X. allbilineans（Gen Bank accession number： FP565176）, and they clustered in the same branch in the phylogenetic tree. The field surveys showed that sugarcane cultivar ‘Guitang46＇ and ‘Guitang06-2081＇ were highly susceptible to leaf scald, the disease incidences were 18%-50%, and even reached 100% in seriously infected fields. The whole leaves blighted in severe infected plants, the node of stem sent forth many lateral buds, and the leaves in lateral buds had white stripes, and sharply caused the reduction of yield and sugar. In this study, we found that sugarcane leaf scald disease was caused by X. albilineans in Guangxi sugarcane region.