青海省当归茎线虫种类鉴定

Identification of Root Rot Nematodes on Angelica sinensis in Qinghai Province

采集和分离到青海省大通县、互助县4个当归茎线虫群体,通过形态特征和测量值比较,以贝叶斯法构建ITS-rDNA系统发育树,并用4种内切酶DdeⅠ、HinfⅠ、Tru9Ⅰ(MseⅠ)和SduⅠ进行ITS-RFLP分析。结果表明,青海省大通县、互助县当归茎线虫群体的形态特征与腐烂茎线虫(Ditylenchus destructor)基本一致,体长略小,雄虫尾长和c(体长/体宽)值略大,雌虫a(体长/尾长)值略大,其他测量值均与腐烂茎线虫模式种一致。通过rDNA-ITS序列系统发育分析,发现青海省大通县、互助县茎线虫群体与腐烂茎线虫群体聚为一支,但不能归为目前已知基因型。rDNA-ITS区段PCR-RFLP结果显示,青海省4个群体与已报道的腐烂茎线虫群体酶切结果不一致,且存在明显差异。经形态与分子生物学特征分析,将这4个线虫群体确定为腐烂茎线虫,表明该线虫已在青海省发生与分布。

Four nematode populations were collected and isolated from Angelica in Datong county and Huzhu county of Qinghai province.Through the comparison of morphological characteristic and measurements,ITS-rDNA region phylogenetic tree was constructed by Bayesian method,and four endonucleases DdeⅠ,HinfⅠ,Tru9Ⅰ(MseⅠ)and SduⅠwere used for ITS-RFLP analysis.The results showed that the morphological characteristics of nematode populations from Datong county and Huzhu county in Qinghai province were consisted with those of Ditylenchus destructor.The body length of these populations was slightly smaller,the tail length and c(body length divided by body width)of males were slightly larger,the a in females(tail length divided by body width at the anus)were slightly larger,and other measurements accorded with D.destructor.Through the sequence phylogenetic analysis of the rDNA-ITS region,populations from Qinghai province were clustered with D.destructor,but did not belong to haplotypes by now.The PCR-RFLP results of four Ditylenchus populations in Qinghai province were significantly different from other D.destructor populations.The nematode populations were identified as D.destructor by morphological and molecular characteristics,indicating that this nematode had occurred and was distributed in Qinghai province.