New Records of Ditylenchus Species from Southern Alberta, Canada

Abstract

The presence of plant-parasitic nematodes (PPNs) in cultivated areas is a limiting factor in achieving marketable crop yield. To control and alleviate the effects of these nematodes and determine appropriate management strategies, species-level identification is crucial. Therefore, we conducted a nematode diversity survey, which resulted in the detection of four Ditylenchus species in cultivated areas of southern Alberta, Canada. The recovered species had six lines in the lateral field, delicate stylets (>10 µm long), distinct postvulval uterine sacs, and pointed to rounded tail tips. The morphological and molecular characterization of these nematodes revealed their identity as D. anchilisposomus, D. clarus, D. tenuidens and D. valveus, all of which are members of the D. triformis group. All of the identified species were found to be new records in Canada except for D. valveus. Accurate Ditylenchus species identification is crucial because false-positive identification can result in the implementation of quarantine measures over the detected area. Our current study not only documented the presence of Ditylenchus species from southern Alberta, but also described their morpho-molecular characteristics and subsequent phylogenetic relationships with related species. The results of our study will aid in the decision on whether these species should become a part of nematode management programs since nontarget species can become pests due to changes in cropping patterns or climate.

Discovery and Characterization of Four Aphelenchid Species from Cultivated Regions of Southern Alberta, Canada

“…Soil nematodes play crucial roles in decomposition and nutrient cycling [ 61 ]. Previous studies in southern Alberta were primarily focused on plant-parasitic species [ 3 , 4 , 11 ]. Our study expands this knowledge by reporting the presence of nematodes falling within a broader category of fungal or root hair feeders.…”

“…However, there are exceptions where some nematode species evolve to become significant parasites of plants. For instance, some members of Aphelenchoides Fischer [7] and Ditylenchus Filipjev [8] are benign and can be cultured on fungi, whereas several other species of these genera are present on plant quarantine lists [9][10][11]. Therefore, a precise and accurate identification is very important for nematode management, phytosanitary purposes or for the selection of resistant crops to the nematode.In the present study, a correct species delimitation between Aphelenchoides spp.…”