杂柑‘W·默科特’黄龙病菌分子鉴定和遗传多样性分析

Molecular Identification and Genetic Diversity of “Candidatus Liberibacter asiaticus” in W. Murcott Tangerine

2017年12月在云南红河新引种的‘W·默科特’杂柑植株上发现疑似黄龙病的叶片斑驳及'红鼻子果'症状。采集疑似的叶片和果实,分别提取其叶片中脉和橘络的DNA,利用黄龙病菌的特异引物对其16S rRNA基因和β–操纵子基因进行PCR扩增,并对扩增产物进行测序分析。研究结果表明,采自云南的‘W·默科特’样品中PCR能够扩增出黄龙病菌的特异条带,通过上述基因进行系统发育分析,发现该病菌归属于黄龙病菌亚洲种;为了进一步探明这些黄龙病菌的遗传多样性,利用3种类型的原噬菌体特异性引物对样品进行扩增分析,结果表明采自云南的‘W·默科特’植株上的黄龙病菌遗传多样性较为丰富。

In December 2017,the W.Murcott tangerine trees,which were newly introduced in Honghe,Yunnan,showed typical HLB symptoms,i.e.blotchy mottle and'red nose'.Leaves and fruit samples of W.Murcott were collected for DNA extraction from midrib and tangerine pith for PCR detection,and sequencing by targeting the 16 S rRNA gene andβ-operator gene of'Candidatus Liberibacter spp.'.The results showed that samples collected from W.Murcott could be amplified the specific bands of'Candidatus Liberibacter asiaticus'(CLas).The phylogenetic analysis based on the 16 S rRNA gene andβ-operator gene revealed the citrus Huanglongbing pathogen of W.Murcott belonged to CLas.In order to further analyze the genetic diversity of CLas,specific primers of three types of prophage were used to amplify DNA samples collected from W.Murcott.The result indicated the high genetic diversity of CLas samples from W.Murcott in Yunnan.