黑龙江腐烂茎线虫群体的分离和鉴定

 本研究对分离自黑龙江省马铃薯中的1个线虫群体Hp1进行形态观察与测量,采用线虫通用引物对其rDNA-ITS进行扩增与序列分析,利用PAUP软件以ML法构建系统发育树,并测定其致病性。结果显示,该线虫群体有6条侧线,头部略缢缩,口针明显,中食道球呈长纺锤形,食道峡部窄而细长;雌虫阴门稍突起,后阴子宫囊较长;雄虫交合刺略向腹面弯曲,引带短,具交合伞。其形态测量值与腐烂茎线虫(Ditylenchus destructor)基本一致。rDNA-ITS PCR扩增片段916 bp,经BLAST比对,该ITS序列与腐烂茎线虫序列相似度最高。系统发育树显示,该群体没有与腐烂茎线虫A、B基因型群体聚在一起,而是与C、D型群体聚为1个分支,且与C型亲缘关系更近。据此,将群体Hp1鉴定为腐烂茎线虫C基因型,这是首次在黑龙江省发现腐烂线虫为害马铃薯。

Isolation and identification of Ditylenchus destructor from Heilongjiang

The morphological characteristics of a nematode population Hp1 isolated from potato in Heilongjiang were observed and measured in this experiment. The rDNA-ITS of the population was amplified using the universal primers and analyzed and the phylogenetic tree was constructed by ML method of PAUP software. The results showed that Hp1 had 6 lateral lines with slightly constricted head, obvious stylet, oval median bulb and narrow and elongated isthmus of the esophagus. The vulva of female slightly raised with long post-uterine sac. The spi-cule of the male was slightly ventral with short gubernaculum and a bursa. The measurements were largely consistent with Ditylenchus destructor. The amplified product of rDNA-ITS was 916 bp and the sequence shared highest similarity with D. destructor. The population Hp1 was not clustered with type A and B, but clustered into one branch with population of haplotype C and D, and had closer affinity with the type C. Hereby, nematode population Hp1 from the potato was confirmed as haplotype C of D. destructor and this is the first report in Heilongjiang.