Prevalence of the root lesion nematode virus (RLNV1) in populations of Pratylenchus penetrans from North America

Authors: VIEIRA, PAULO - Virginia Tech; Peetz, Amy; MIMEE, BENJAMIN - Agriculture And Agri-Food Canada; SAIKAI, KANAN - University Of Wisconsin; Mollov, Dimitre; MACGUIDWIN, ANN - University Of Wisconsin; Zasada, Inga; Nemchinov, Lev

Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/24/2020
Publication Date: 5/20/2020
Citation: Vieira, P., Peetz, A.B., Mimee, B., Saikai, K., Mollov, D.S., Macguidwin, A., Zasada, I.A., Nemchinov, L.G. 2020. Prevalence of the root lesion nematode virus (RLNV1) in populations of Pratylenchus penetrans from North America. Journal of Nematology. 52:e2020-45. https://doi.org/10.21307/jofnem-2020-045.
DOI: https://doi.org/10.21307/jofnem-2020-045

Interpretive Summary: Root lesion nematode virus has been recently discovered in the agriculturally important root lesion nematode species Pratylenchus penetrans. It was found in an isolated nematode population collected from soil samples in Beltsville, Maryland. In this study, we have investigated a distribution of RLNV in 31 geographically distinct nematode populations obtained from different crops. Our results demonstrate that RLNV is widespread in North American populations of the nematode and exhibits low genetic variability in the examined regions of the viral genome. It is expected that the study will be of interest to plant nematologists, virologists, epidemiologists and extension specialists working in the field of plant pathology.

Technical Abstract: Presently, the number of viruses identified in the phylum Nematoda is very limited. Considering the vast diversity of species within this phylum, more viruses naturally infecting nematodes are likely to be discovered. In the past few years, several novel viruses have been identified from wild populations of free-living, animal-parasitic, and sedentary plant-parasitic nematodes (PPN). In our laboratory, we have recently discovered a new virus (the root lesion nematode virus, RLNV1) associated with the migratory nematode species Pratylenchus penetrans, an endoparasitic migratory PPN, which can infect a broad range of economically important crops and is among the top three most damaging species of PPN. Here, in order to obtain more data on distribution of the RLNV1, we studied geographically distinct populations of P. penetrans, obtained from different crop systems in North America. We also compared sequence variability of the identified RLNV1 isolates in their helicase and RNA-dependent RNA polymerase regions to assess potential genetic diversity of the virus. Our results suggest that RLNV1 is prevalent in different geographic populations of P. penetrans and exhibits a low genetic variation in the analyzed regions of the genome. These findings may potentially indicate a presence of virus-free or virus-resistant P. penetrans populations, especially in the case of positive and negative results in nematodes collected from the same crop (potato and soybean) and in the contiguous geographic locations. Negative results obtained with P. penetrans populations collected from raspberry and cherry may also suggest host-dependent susceptibility of P. penetrans to RLNV1. If true, this would likely to be related to the genetic variability among the nematode isolates rather than to the virulence of RLNV1, which exhibited considerable homogeneity in the two regions examined in this study.