琯溪蜜柚黄龙病病原的克隆及序列分析  

Cloning and sequencing of citrus huanglongbing pathogen in Guanximiyou pomelo

作　　者：田亚南[1] 柯穗 李韬[2] 柯冲[2] 

机构地区：[1]美国德克萨斯大学,德克萨斯州77845 [2]福建省农业科学院,福建福州350003

出　　处：《福建农业学报》2002年第1期11-15,共5页Fujian Journal of Agricultural Sciences

基　　金：福建省科技厅资助项目 (97-Z-5 )

摘　　要：溪蜜柚是中国大陆柚类中的优质品种。近年来 ,在福建省的产地发现溪蜜柚叶片表现斑驳的病树 ,其叶片斑驳与柑桔黄龙病的叶片病状十分相似。据实验结果证明 :该病能通过病梢嫁接传染到柚和柑桔的健苗 ;在电镜下观察到病株韧皮部寄生着大量 BL Os,其形态和构造均与柑桔黄龙病病原 (L iberobacter asiaticum)相似 ;经PCR扩增与 Southern Blot分子杂交测定 ,表明该病原 DNA PCR产物与柑桔黄龙病病原 PCR产物之间具有很高的同源性。初步认为该病很可能是柑桔黄龙病引起的。为了进一步明确该病与柑桔黄龙病的关系 ,对病原 DNA片段进行扩增、克隆和序列分析 ,并与柑桔黄龙病病原基因相应序列进行比较 ,结果表明该病原与亚洲柑桔黄龙病病原 (L.asiaticum)相应基因序列的同源率达 94 .2 % ,而与非洲柑桔黄龙病病原 (L.africanum)的同源率仅为75 .0 %。进一步证明溪蜜柚叶片斑驳是柑桔黄龙病引起的 ,其病原是 L.Guanximiyou is one of the best pomelo variety in China. In the recent years, diseased plant of Guanximiyou pomelo have been found in the production areas in Fujian Province. This disease is graft\|transmissible. Symptom of diseased plant showed leaf mottle which looked like that of citrus Huanglongbing. Bacteria\|like\|organism(BLO) associated with this disease was found to be similar to that of citrus Huanglongbing based on the morphology and structure of the BLO by electron microscopy. The PCR products of pathogen DNA from Guanximiyou pomelo obtained with gene\|specific primers for Huanglongbing Liberobacter and southern hybridization of the PCR products with oligonucleotide probe specific sequence for the Liberobacter pathogen showed that there was a remarkable degree of DNA homogenity between the pathogen from diseased pomelo and that of citrus Huanglongbing plant. These results suggested that this disease was caused by citrus Huanglongbing pathogen. In order to confirm the relationship between this disease and citrus Huanglongbing, further study was conducted to clone the PCR products of DNA fragment obtained from the pathogen of diseased pomelo, to analysis their sequence and to compare the DNA sequences with those of the citrus Huanglongbing Liberobacter. The results showed that the cloned DNA shared 94 2 % and 75 0% homogeneity of sequence with that of L. asiaticum and L. africanum respectively. This indicated once more that the pomelo disease was the same as citrus Huanglongbing and that the pathogen belonged to a member of L. asiaticum .

关 键 词：Guan溪蜜油 黄龙病病原 克隆 序列分析 

分 类 号：S436.661.1[农业科学—农业昆虫与害虫防治]