Development of Species-Specific Primer Pairs for the Molecular Diagnosis of Ditylenchus arachis

Ditylenchus arachis was firstly found in hulls and seeds of peanut (Arachis hypogaea) in 2014 and is an economically important nematode pest of peanut in northern China.The rDNA-ITS regions of 7 D. arachis populations were PCR amplified.Sequence analysis showed that the interspecific diversity was found between D. arachis and other Ditylenchus species based on ITS-1 sequences.A set of species-specific primers (named DARF /DARR) for rapid identification of D. arachis was designed based on the sequence analysis of rDNA-ITS 1.The primers were sensitive to generate a specific band of the correct size (171 bp) from DNA template of a single different developmental stage of D. arachis.The reliability of the primers was tested by screening 18 different geographical populations of D. arachis in China, and an expected band size was produced for all populations tested.The closely related Ditylenchus species and general nematodes collected from soil of peanut were also tested for the primers, no specific band was amplified.Given its specificity, sensitivity and reliability, the specific primers should be of great benefit to accurate identification of D. arachis, which is fundamental for effective management of the nematode.