Morphological And Genetic Analysis On Different Populations Of Ditylenchus Destructor

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 Rsaâ… ,Haeâ…¢,Msp I, Hinfâ… and Aluâ… .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 Rsaâ… ,Haeâ…¢,HinfI and Aluâ… .ITS1-PCR-RFLP patterns olD. 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 ofDeSD1,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 betweenl%and 4%,and of nine populations ofgenotype 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 Morphometrie data supported that two genotypes of D.destructor were existed in China.