A new root‐knot nematode, Meloidogyne silvestris n. sp. (Nematoda: Meloidogynidae), parasitizing European holly in northern Spain

Abstract

High infection rates of European holly ( Ilex aquifolium ) feeder roots by an unknown root-knot nematode were found in a holly forest at Arévalo de la Sierra (Soria province) in northern Spain. Holly trees infected by the root-knot nematode showed some decline and low growth. Infected feeder roots were distorted and showed numerous root galls of large (8-10 mm) to moderate (2-3 mm) size. Morphometry, esterase and malate dehydrogenase electrophoretic phenotypes and phylogenetic trees of sequences within the ribosomal DNA (rDNA) demonstrated that this nematode species differs clearly from other previously described root-knot nematodes. Studies of host-parasite relationships showed a typical susceptible reaction in naturally infected European holly plants, but did not reproduce on a number of cultivated plants, including tomato, grapevine, princess-tree and olive. The species is described here, illustrated and named as Meloidogyne silvestris n. sp. The new root-knot nematode can be morphologically distinguished from other Meloidogyne spp. by: (i) roundish perineal pattern, dorsal arch low, with fine, sinuous cuticle striae, lateral fields faintly visible; (ii) female excretory pore level with stylet knobs, or just anterior to them, EP/ST ratio about 0·8; (iii) second-stage juveniles with hemizonid located 1 to 2 annuli anterior to excretory pore and short, sub-digitate tail; and (iv) males with lateral fields composed of four incisures, with areolated outer bands. Phylogenetic trees derived from maximum parsimony analysis based on 18S, ITS1-5·8S-ITS2 and D2-D3 of 28S rDNA showed that M. silvestris n. sp. can be differentiated from all described root-knot nematode species, and it is clearly separated from other species with resemblance in morphology, such as M. ardenensis , M. dunensis and M. lusitanica .

A new root-knot nematode Meloidogyne spartelensis n. sp. (Nematoda: Meloidogynidae) in Northern Morocco

“…It also differs phylogenetically from this Bgraminisĝ roup of species but is related to M. dunensis and M. silvestris associated in the Iberian peninsula with dicotyledonous plants and with woody plants respectively (Palomares-Rius et al 2007;Castillo et al 2009). The reproduction on tomato of this new species also Bayesian 50 % majority rule consensus trees as inferred from D2 and D3 expansion segments of 28S rDNA sequences alignments under the GTR+I+G model.…”

“…Outgroup taxa for each dataset were chosen according to previous published data (Castillo et al 2009). The newly obtained and published sequences for each gene were aligned using MAFFT (Katoh et al 2002) with default parameters.…”

“…The application of molecular methods to studies of RKN population structure and systematics have revealed that some long-assumed single species are in fact cryptic species that are morphologically indistinguishable but may be phylogenetically distant to one another (Gamel et al 2014). Sequences of nuclear ribosomal (rDNA) and mitochondrial DNA (mtDNA) have been used for molecular characterisation and reconstruction of phylogenetic relationships within the genus Meloidogyne during the last decade (Powers and Harris 1993;Ziljstra et al 2000;Adam et al 2007;Adams et al 2009;Castillo et al 2009). The analysis of isozyme electrophoretic patterns, in particular esterase (Est) and malate dehydrogenase (Mdh), as well as several molecular approaches have proved to be a valuable tool for precise identification of Meloidogyne species (Blok and Powers 2009).…”

First report of Laimaphelenchus heidelbergi (Nematoda: Aphelenchoididae) in Europe

“…Primers for amplification of the D2/D3 expansion segments of LSU were the forward primer D2A (5′‐ACA AGT ACC GTG AGG GAA AGT TG‐3′) and reverse primer D3B (5′‐TCG GAA GGA ACC AGC TAC TA‐3′; Castillo et al. ).…”

Identificación de especies de Meloidogyne asociadas a plantas ornamentales de altura en Costa Rica.

“…El nematodo aislado de F. pumila fue analizado por medio de secuenciación capilar con colaboración del Instituto de Agricultura Sostenible, España. Se utilizaron los imprimadores D2D3 e ITS (Hugall et al, 1999;Castillo et al, 2009). El proceso de secuenciación se aplicó únicamente a este aislamiento, debido a que los patrones generados no coincidían con los reportados en la literatura.…”