Morphological and Molecular Characterization of Nothotylenchus medians and N. similis (Nematoda: Anguinidae) from Southern Alberta, Canada

Abstract

The nematode family, Anguinidae, is a diverse group of polyphagous nematodes, generally known as fungal feeders or parasites of aerial plant parts. Here, we present the morphological and molecular characterization of adult females of two Nothotylenchus species, N. medians and N. similis, along with host association and geographical distribution data of the genus. Both species are recorded as new reports from Canada and designated as reference populations for future studies. Morphological or morphometrical variation was not observed in the Canadian population of N. medians and N. similis, in comparison with the original description. Phylogenetic analyses based on 18S and D2–D3 of 28S genes placed both species within Anguinidae. Since the biology of the genus Nothotylenchus has not been rigorously characterized, the habitat and distribution information presented in this study will shed some light on the ecology of these nematodes. Notably, the detection of N. medians and N. similis in our nematode inventory survey indicates that considerable Nothotylenchus diversity is hidden in these soils. Consequently, increased surveys and more in-depth research are needed to explore the full diversity of anguinids inhabiting these cultivated areas.

Description of Nothotylenchus savadkoohensis n. sp. (Rhabditida, Anguinidae) from Iran based on morphological and molecular data

“…The phylogenetic relationships of the presently described new species with other relevant species and genera were reconstructed using two LSU D2–D3 and ITS rDNA markers. The general topology of the currently reconstructed LSU tree is in agreement with the previous LSU phylogenies (e.g., Munawar et al, 2022 ), showing the available sequences of Nothotylenchus occupy distant placements in the tree, and the genus is not monophyletic. Thus, an integrative approach using both morphological and molecular data should be exploited while assigning species into this genus.…”

“…Most Nothotylenchus species, especially those in old literatures, have been established based upon classic criteria and molecular data of type or topotype populations of them are currently lacking. On the other hand, descriptions of several recently established species and recent taxonomic studies of previously known species include molecular data (e.g., Jalalinasab et al, 2018 ; Esmaeili et al, 2016 , 2017 ; Munawar et al, 2022 ). Based on available data, the sequenced species of the genus for their ribosomal DNA, occupy distant placements in corresponding phylogenetic trees, indicating the genus is not monophyletic ( Jalalinasab et al, 2018 ; Munawar et al, 2022 ).…”