Sequence variation in ribosomal DNA and in the nuclear hsp90 gene of Pratylenchus penetrans (Nematoda: Pratylenchidae) populations and phylogenetic analysis (vol 152, pg 355, 2018)

During nematode surveys in France and in South Italy, several Pratylenchus populations were collected which were morphologically related to P. penetrans. The root-lesion nematode P. penetrans is widely distributed across the world and is considered one of the most economically damaging species in the genus. Correct identification of this species is needed. Unfortunately, most of the species belonging to the penetrans group are very difficult to identify morphologically. Thus DNA-based identification can be used as a rapid diagnostic tool. Therefore the ITS, the D2-D3 expansion domains of the 28S rRNA gene and the hsp90 gene of P. penetrans and of other Pratylenchus species were amplified. Sequence analyses of all molecular markers confirmed the high variability of P. penetrans genome. The phylogenetic reconstruction based on the sequences of the ITS and D2-D3 expansion domains confirmed the high sequence variability among the different populations of P. penetrans and the close relationships with the penetrans group. Furthermore, the isolation of two variants of the hsp90 gene in P. penetrans may be related to adaptation to environmental changes and different host plants.