Morphological and molecular characterisation of Paralongidorus rex Andrássy, 1986 (Nematoda: Longidoridae) from Poland and Ukraine

Abstract

Paralongidorus rex was found for the first time in Poland and Ukraine. This paper describes females and juveniles from four populations of this species on the basis of morphology and morphometrics and provides molecular characterization using 18S, ITS1 and D2-D3 expansion segments of 28S rRNA gene sequences. Morphometrically, females from these populations differed slighty in V ratio (means in four populations: 41.9; 42.7; 46.1; 46.8) and odontostylet length (166.6; 170.6; 191.5; 193.2). Phylogenetic analysis showed that P. rex had a sister relationship with P. iranicus. PCR-D2-D3 of 28S-RFLP diagnostic profiles with five enzymes are given. Additionally, information on new host plants and map of distribution for P. rex are provided. The new record of this nematode species, previously identified as Paralongidorus sp.

Description and molecular phylogeny of one new and one known needle nematode of the genus Paralongidorus (Nematoda: Longidoridae) from grapevine in Portugal using integrative approach

“…The taxonomic and systematic position of the genus Paralongidorus Siddiqi, Hooper & Klan, 1963 within the family Longidoridae (Thorne, 1935) Meyl, 1961 appears to be accepted by the scientific community, however the species composition are continuously being subject of debate (Hunt 1993, Siddiqi et al 1993, Coomans 1996, Escuer & Arias 1997, Decraemer & Robbins 2007. This genus, member of the commonly known needle nematodes, is quite diverse with about 90 valid species of migratory ectoparasites that parasitise a wide range of agronomic crops, ornamentals, and forest trees (Taylor & Brown 1997, Decraemer & Robbins 2007, Palomares-Rius et al 2013, Kornobis et al 2015, Barsi & De Luca 2017. This group of phytopathogenic species are of global interest because they cause directly damage on the roots of the host plant attributable to their ectoparasitic feeding and one species is able to transmit damaging nepoviruses (Taylor & Brown 1997, Decraemer & Robbins 2007.…”

“…Morphometric and morphological identification within this genus at species level is mainly based on characteristics of adult females (Escuer & Arias 1997).However, the high intraspecific variability of some diagnostic features and the great diversity in phenotypic plasticity make species identification based on gross morphology and internal anatomical features a technically difficult task even for experts. Recently, the sequencing of RNA-based markers is an increasingly powerful approach for the molecular diagnostics and for understanding their inter-and intra-genetic variability (Palomares-Rius et al 2013, Kornobis et al 2015, Barsi & De Luca 2017. Several ribosomal RNA (rRNA) genes are used for molecular characterizations of these nematodes: partial 28S rRNA gene (He et al 2005, Palomares-Rius et al 2008, Pedram et al 2012, Kornobis et al 2015, Barsi & De Luca 2017, 18S rRNA gene (Palomares-Rius et al 2008, Pedram et al 2012, Kornobis et al 2015 and internal transcribed spacer (ITS) region of the rRNA genes (Palomares-Rius et al 2008, Pedram et al 2012, Kornobis et al 2015, Barsi & De Luca 2017.…”

“…Recently, the sequencing of RNA-based markers is an increasingly powerful approach for the molecular diagnostics and for understanding their inter-and intra-genetic variability (Palomares-Rius et al 2013, Kornobis et al 2015, Barsi & De Luca 2017. Several ribosomal RNA (rRNA) genes are used for molecular characterizations of these nematodes: partial 28S rRNA gene (He et al 2005, Palomares-Rius et al 2008, Pedram et al 2012, Kornobis et al 2015, Barsi & De Luca 2017, 18S rRNA gene (Palomares-Rius et al 2008, Pedram et al 2012, Kornobis et al 2015 and internal transcribed spacer (ITS) region of the rRNA genes (Palomares-Rius et al 2008, Pedram et al 2012, Kornobis et al 2015, Barsi & De Luca 2017. Kornobis et al (2015) designed a PCR-RFLP of the D2D3 region of 28S rRNA gene with five restriction enzymes to establish diagnostic profiles from P. rex Andrássy, 1986.…”

“…Several ribosomal RNA (rRNA) genes are used for molecular characterizations of these nematodes: partial 28S rRNA gene (He et al 2005, Palomares-Rius et al 2008, Pedram et al 2012, Kornobis et al 2015, Barsi & De Luca 2017, 18S rRNA gene (Palomares-Rius et al 2008, Pedram et al 2012, Kornobis et al 2015 and internal transcribed spacer (ITS) region of the rRNA genes (Palomares-Rius et al 2008, Pedram et al 2012, Kornobis et al 2015, Barsi & De Luca 2017. Kornobis et al (2015) designed a PCR-RFLP of the D2D3 region of 28S rRNA gene with five restriction enzymes to establish diagnostic profiles from P. rex Andrássy, 1986. Recently, Barsi & De Luca (2017) designed a PCR-RFLP of ITS region based on six restriction enzymes for genotyping of species-specific variations for P. francolambertii Barsi & De Luca, 2017.…”

Research Note. New data on plant parasitic nematode Longidorus distinctus Lamberti, Choleva & Agostinelli, 1983 (Nematoda: Longidoridae) from Poland

“…) were chosen for closer study of morphometrics and DNA markers. DNA isolation and PCR conditions as described by Kornobis et al (2015). PCR was performed using primers D2A and D3B (Nunn, 1992) for the D2-D3 28S rDNA and rDNA2 (Vrain et al, 1992) and rDNA5.8S primers (Cherry et al, 1997) for (partial) 18S-ITS1-5.8S (partial) region.…”