Overview of the Genus Boleodorus and First Reports of Boleodorus thylactus and B. volutus from Southern Alberta, Canada

SIMPLE SUMMARY: Two Boleodorus species were detected in cultivated areas of southern Alberta. The aim of the present work was to characterize the discovered populations of Boleodorus using morphological and molecular methods. Boleodorus is the least studied genus in family Tylenchidae, with very few species reported after formal descriptions and outside their type locality. To date, Boleodorus species are not considered nematode pest species, rather they can serve as environmental indicators. Therefore, it is important to quantify and monitor the population densities of these species for soil health management studies. The current study encompasses the distribution and host association of all described Boleodorus species. In addition, morphometrical characters of all valid species are listed for their prompt identification. ABSTRACT: The present study provides the morphological and molecular characterization of Boleodorus thylactus and B. volutus populations, recovered from agricultural fields of southern Alberta. Despite a significant abundance of this group of nematodes, none of the Boleodorus species were previously reported in Canada. Therefore, representative adult specimens of each population were photographed and examined morphometrically. Phylogenetic trees were reconstructed using partial D2–D3 expansion segments of the 28S and 18S rDNA sequences to understand the relationships of Boleodorus species with Tylenchidae-related genera. Boleodorus species are relevant to soil ecological studies and therefore we summarized the important morphological and morphometric characters in tabular form for easy and efficient species identification. Moreover, we discuss the associated hosts and the distribution of all described Boleodorus species. This study will serve as a guide and basic framework for species diagnostics in the genus Boleodorus and will aid in filling the gaps in our knowledge of the species present in our cultivated lands.