广西宜州甘蔗白条病调查及分子检测

Investigation and molecular detection of sugarcane leaf scald disease caused by Xanthomonas albilineans in Yizhou,Guangxi

甘蔗白条病是一种检疫性细菌病害,具有危害性大,潜伏期长的特点,由白条黄单胞菌(Xanthomonas albilineans)引起,在种植甘蔗的主要国家或地区均有发生。2020年在广西宜州蔗区发现疑似感染甘蔗白条病蔗株,为明确病原及发生情况,为其科学防控提供科学依据。本研究对不同甘蔗品种新植和宿根蔗进行发病率调查,并采集病样进行PCR检测分析。田间调查结果显示:不同品种自然发病率不同,桂糖44新植和宿根蔗均有白条病发生,且宿根蔗发病率高于新植蔗,其中新植蔗发病率为8%~18%,平均发病率为13.83%;宿根蔗发病率为18%~34%,平均发病率为24.71%。而桂糖42、桂糖55、柳城05-136等3个品种新植和宿根蔗均未发现白条病。PCR检测结果表明:有10份样品扩增出608 bp的特异性条带,阳性检出率为90.9%,所得序列与X. albilineans序列同源性高达100%,且在构建的系统发育树处于同一分支。本研究结果表明,广西宜州蔗区发现由X. albilineans引起的甘蔗白条病。

Sugarcane leaf scald disease is a kind of quarantine bacterial disease,which has the characteristics of great harm and long incubation period. It is caused by Xanthomonas albilineans and occurs in major sugarcane-producing countries or regions. In 2020,suspected sugarcane leaf scald infected plant was found in Yizhou District,Guangxi Province. In order to provide scientific basis for identification pathogen,occurrence situation and scientific control,the incidence rate of new-planted and ratoon sugarcane of different sugarcane varieties was investigated. Then diseased samples were collected for PCR detection and analysis. Field survey results showed that the natural incidence rate of different varieties were different. The sugarcane leaf scald disease was found in GuiTang 44 in both new-planted and ratoon sugarcane,and the incidence rate of ratoon sugarcane was higher than new-planted sugarcane. Among them,the incidence rate of new-planted and ratoon sugarcane was 8%-18% and 18%-34%,respectively,and the average of incidence rate was 13.83% and 24.71%,respectively. However,no leaf scald disease was found in new-planted and ratoon sugarcane of three varieties,including GuiTang 42,GuiTang 55and LiuCheng 05-136. PCR detection results showed that ten samples were amplified a specific band of about 608 bp in size with a positive detection rate of 90.9%. The sequence homology of resulting sequence and X. albilineans was as high as 100% and the phylogenetic tree under construction was in the same branch. The results of this study showed that sugarcane leaf scald disease was found in Yizhou,Guangxi,which caused by X. albilineans.