ABSTRACT
This study delves into the diagnosis of pin nematodes (Paratylenchus spp.) in Spain based on integrative taxonomical approaches using 24 isolates from diverse natural and cultivated environments. Eighteen species were identified using females, males (when available) and juveniles with detailed morphology-morphometry and molecular markers (D2-D3, ITS and COI). Molecular markers were obtained from the same individuals used for morphological and morphometric analyses. The cryptic diversity using an integrative taxonomical approach of the Paratylenchus straeleni-species complex was studied, consisting of an outstanding example of the cryptic diversity within Paratylenchus and including the description of a new species, Paratylenchus parastraeleni sp. nov. Additionally, 17 already known species were identified comprising P. amundseni, P. aciculus, P. baldaccii, P. enigmaticus, P. goodeyi, P. holdemani, P. macrodorus, P. neoamblycephalus, P. pandatus, P. pedrami, P. recisus, P. sheri, P. tateae, P. variabilis, P. veruculatus, P. verus, and P. vitecus. Eight of these species need to be considered as first reports for Spain in this work (viz. P. amundseni, P. aciculus, P. neoamblycephalus, P. pandatus, P. recisus, P. variabilis, P. verus and P. vitecus). Thirty-nine species of Paratylenchus have been reported in Spain from cultivated and natural ecosystems. Although we are aware that nematological efforts on Paratylenchus species in Southern Spain have been higher than that carried out in central and northern part of the country, the present distribution of the genus in Spain, with about 90% of species (35 out of 39 species, and 24 of them confirmed by integrative taxonomy) only reported in Southern Spain, suggest that this part of the country can be considered as a potential hotspot of biodiversity.
ABSTRACT
Reniform nematodes of the genus Rotylenchulus are semi-endoparasites of numerous herbaceous and woody plant roots that occur largely in regions with temperate, subtropical, and tropical climates. In this study, we compared 12 populations of Rotylenchulusborealis and 16 populations of Rotylenchulusmacrosoma, including paratypes deposited in nematode collections, confirming that morphological characters between both nematode species do not support their separation. In addition, analysis of molecular markers using nuclear ribosomal DNA (28S, ITS1) and mitochondrial DNA (coxI) genes, as well as phylogenetic approaches, confirmed the synonymy of R. macrosoma with R. borealis. This study also demonstrated that R. borealis (= macrosoma) from Israel has two distinct rRNA gene types in the genome, specifically the two types of D2-D3 (A and B). We provide a global geographical distribution of the genus Rotylenchulus. The two major pathogenic species (Rotylenchulusreniformis and Rotylenchulusparvus) showed their close relationship with warmer areas with high annual mean temperature, maximum temperature of the warmest month, and minimum temperature of the coldest month. The present study confirms the extraordinary morphological and molecular diversity of R. borealis in Europe, Africa, and the Middle East and comprises a paradigmatic example of remarkable flexibility of ecological requirements within reniform nematodes.
