甘薯茎线虫病是农业上生产的重要病害，其病原腐烂茎线虫 (Ditylenchus destructor) 为我国禁止进境植物检疫性有害生物。腐烂茎线虫最初是在马铃薯上发现的，并导致马铃薯腐烂，但在我国主要危害甘薯的生产，也可以侵染当归，盆栽接种试验表明也可以侵染花生。本实验以来自国内的13个腐烂茎线虫群体和1个荷兰的鳞球茎茎线虫群体为研究材料，做了以下几方面的研究： 对来自国内的13个腐烂茎线虫群体和1个荷兰的鳞球茎茎线虫群体进行了ITS1 区的扩增和5种限制性内切酶Rsa I、Hae III、Msp I、 Hinf I和Alu I的限制性片段长度多态性（RFLP）分析，发现13个腐烂茎线虫群体存在两种不同的酶切图谱，两种图谱在Rsa I、Hae III、 Hinf I 和 Alu I 4种酶的酶切位点上存在差异，而鳞球茎茎线虫群体的RFLP图谱与腐烂茎线虫的RFLP图谱相比则在5种限制性内切酶的酶切位点上都存在差异。 根据RFLP酶切图谱的差异，可以将腐烂茎线虫的13个群体分为A和B两个基因型。A 基因型包括DeSD1、DeSD2、DeSD3和DeJS1 四个群体，B基因型包括DeAH1、DeAH2、 DeHB1、DeHB2、DeJS2、DeSX、DeSD4、DeTJ1和DeTJ2 九个群体。 对ITS1区的序列进行比对，发现A 基因型4个群体的差异在1％～4％之间，B基因型9个群体的差异在0～1％之间，腐烂茎线虫种内不同基因型群体之间的差异在29％～30％之间，鳞球茎茎线虫与腐烂茎线虫种间的差异在39％～48％之间。 对4个腐烂茎线虫群体和1个鳞球茎茎线虫群体进行了形态测计，发现腐烂茎线虫两个基因型群体间除雌虫在4个形态测计值c值、尾长、V值和 V’值存在显著差异外，在其他形态测计值上无显著差异。ITS1区的RFLP图谱和序列比对以及形态测计数据都表明中国的腐烂茎线虫群体存在两个基因型。

Ditylenchus destructor caused crucial diseases in agriculture. Ditylenchus destructor is forbidden to enter by quarantine. Ditylenchus destructor was discovered in potato firstly causing potato rotting, but the sweet potato is mainly invaded by Ditylenchus destructor in China. Angelica and earthnut can also be invaded. 13 Chinese populations of Ditylenchus destructor and one Dutch population of Ditylenchus dipsaci had been taken as research materials on such several aspects: ITS1 (internal transcribed spacer 1) regions were amplified from 13 Chinese populations of Ditylenchus destructor and one Dutch population of Ditylenchus dipsaci. ITS1 regions of these populations were digested by five enzymes Rsa I, Hae III, Msp I, Hinf I and Alu I. ITS1-PCR-RFLP patterns revealed that 13 Chinese populations of D. destructor had two different ITS1-PCR-RFLP patterns which were different in fragments obtained from four enzymes Rsa I, Hae III, Hinf I and Alu I. ITS1-PCR-RFLP patterns of D. dipsaci and D. destructor were different in fragments obtained by all five enzymes. Thirteen Chinese populations of D. destructor were divided into two genotypes, i.e. genotype A and B. Genotype A included populations of DeSD1, DeSD2, DeSD3 and DeJS1, and genotype B included populations of DeAH1, DeAH2, DeHB1, DeHB2, DeJS2, DeSX, DeSD4, DeTJ1 and DeTJ2. ITS1 regions were also sequenced and alignments of sequenced results of ITS1 regions reveled that the pairwise sequence divergences of four populations of genotype A were between1 % and 4 %, and of nine populations of genotype B were between 0 and 1%. The different populations of two genotypes of D. destructor were between 29% and 30%. The sequence divergences of D. dipsaci and D. destructor were between 39% and 48%. Morphometric characters were analysed on four populations of D. destructor and one population of D. dipsai. The results demonstrated that there were no significant differences in most morphometric characters except c, tail, V and V’ among populations of two genotypes A and B of D. destructor. The ITS1-RFLP patterns, ITS1 sequence analysis and Morphometric data supported that two genotypes of D. destructor were existed in China.