Page 228 - Plant Canada 2024 Proceeding

PLANT CANADA 2024

the isolates was evaluated under controlled conditions on canola at both the seedling and adult plant
stages. All tested isolates were classified as belonging to the A1/D1 lineage of V. longisporum. The
phylogenetic and pathogenicity analyses are in progress.

[P49] DIVERSITY OF SOIL NEMATODES FROM IRRIGATED AGRICULTURAL REGIONS OF
SOUTHERN ALBERTA, CANADA. Maria Munawar and Dmytro P. Yevtushenko. Department of
Biological Sciences, University of Lethbridge, 4401 University Drive W, Lethbridge, AB, Canada, T1K
3M4
Correspondence to: dmytro.yevtushenko@uleth.ca

The soil is a vital component of the farming system, where soil-inhabiting nematodes play important
ecological roles. Nematodes progress through a life cycle comprising egg, juvenile, and adult stages.
These organisms feed on soil microbes, fungal propagules, or plant roots for growth and development.
Whereas some nematode species contribute to soil health as beneficial organisms, others can pose
significant economic threats as plant parasites; hence, understanding the presence and distribution of soil
nematodes holds paramount importance. In the present work, we conducted a nematode inventory
survey to understand the diversity of nematodes residing in the agroecosystems of southern Alberta. To
this end, we collected samples from irrigated, cultivated fields, and adjacent areas covered with natural
vegetation, to compare the abundance and host association of recovered nematodes. The survey
indicated the presence of various groups, such as spiral, stunt, pin, and ring nematodes, as well as
fungal- and root hair-feeding nematodes. We found that spiral, stunt, and pin nematodes were more
abundant in cultivated field soil, as compared with undisturbed soils under natural vegetation. The
coexistence of diverse nematode groups in cultivated regions does not inevitably lead to crop yield losses
because not all nematode species exert detrimental effects on plants. However, we emphasize that the
recognition and accurate taxonomical identification of detected species are important to assess potential
future threats. Additionally, economically insignificant nematode species may evolve into parasites under
altered habitat conditions, agronomic practices, cultivar choices, or rotation cycles. Therefore, proactive
identification of overlooked nematode infestation issues, coupled with the continuous implementation of
preventive crop protection and pest management measures, is crucial for sustainable agriculture.

[P50] EXPLORING THE MICROSCOPIC WORLD: IDENTIFICATION OF PLANT-ASSOCIATED
NEMATODES WITH LIGHT AND SCANNING ELECTRON MICROSCOPY. Maria Munawar, Michele
Konschuh, and Dmytro P. Yevtushenko. Department of Biological Sciences, University of Lethbridge,
4401 University Drive W, Lethbridge, AB, Canada, T1K 3M4
Correspondence to: dmytro.yevtushenko@uleth.ca

Plant-parasitic nematodes represent a formidable threat to global agriculture, causing annual crop losses
of up to eighty billion dollars. Precise identification of new or potentially harmful nematode species is
crucial to the development of effective control and quarantine strategies. In our nematode studies, we
employ a combined approach of light and electron microscopy to elucidate nematode characteristics.
While molecular techniques offer valuable supplementary tools, sole reliance on them is limited,
especially considering the lack of sequence data for many nematode species in public databases. As a
result, morphological identification remains essential in nematode taxonomy. Light microscopy facilitates
traditional morphological examination, enabling the calculation of morphometric ratios. Scanning electron
microscopy (SEM) delivers high-resolution, three-dimensional images, unraveling intricate features, such
as submedian lobes on lip regions, oral and amphidial apertures, cephalic annuli, and tail structures. In
the present study, we identified Mesocriconema curvatum, M. rusticum, Paratylenchus aculentus, P.
goldeni, Helicotylenchus oscephalus, and Filenchus sandneri in irrigated fields of southern Alberta, and
recorded the first comprehensive documentation of these species through detailed light microscopy and
SEM. SEM significantly enhanced nematode species identification, providing detailed, high-quality
imaging for researchers and taxonomists. Our findings will aid in distinguishing closely related species
and contribute to a better understanding of nematode biology and morphology.

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