Page 179 - Plant Canada 2024 Proceeding

PLANT CANADA 2024

Fusarium head blight (FHB) is a severe fungal disease affecting wheat, barley, oats, other small grain
cereals, grasses, and corn. Although FHB has been a common and damaging disease in Manitoba for
nearly three decades, it is a relatively ‘new’ disease in Alberta. Thus, a field survey from 2006 to 2023
was carried out to study the FHB status and prevalence in Alberta fields. Fusarium-like species were
isolated, identified, and counted from samples from wheat heads randomly collected from selected fields
in every wheat-producing county in Alberta from the Peace River region in the north through to the most
southern regions in Alberta. A relatively low level (0.54%) of FHB prevalence in 2006, increased up to
70% by 2021 demonstrating significant change in FHB prevalence during this period, and the
considerably high risk of future FHB infection in wheat in Alberta. Similarly, FHB incidence also increased
steadily since 2006. In contrast, a very low FHB severity was found in Alberta fields across time, except
for 2015 and 2016, which had favorable environmental conditions that promoted the development of FHB.
The most frequently recovered species were F. graminearum, F. avenaceum, and F. culmorum followed
by F. poae up to 2015. In 2006, F. graminearum accounted for 7.57% of all species; however, by 2021,
that percentage had dropped to 3.5%, making F. graminearum an uncommon species in Alberta fields.
The distribution of F. graminearum showed that it is no longer concentrated in southern Alberta.
Interestingly F. poae showed a rapid increase in prevalence when compared to other Fusarium species
and became the dominant species in 2021. Fusarium graminearum isolates comprising 3ADON genotype
were more common over 15ADON isolates, supporting a shift from 15ADON to 3ADON in Alberta over
this period. Changes in the environmental conditions and other agronomical practices may play a role in
species composition dynamics and the shift towards 3ADON in Alberta. Since the prevalence and
incidence of FHB is increasing in Alberta fields, it is important to conduct further annual surveys to
monitor the status of FHB in this province. This survey was continued up to 2023 and the data analysis
for 2022 and 2023 is underway.

[O148] ARE NEMATODES INVOLVED IN THE EMERGING CHICKPEA HEALTH ISSUE IN
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SASKATCHEWAN? Fernanda Gouvea Pereira , Mario Tenuta , Michelle Hubbard , and Sarah
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Anderson . Department of Soil Science, University of Manitoba, Winnipeg, Manitoba, Canada;
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2 Agriculture and Agri-Food Canada, Swift Current, Saskatchewan, Canada; and Saskatchewan Pulse
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Growers, Saskatoon, Saskatchewan, Canada
Correspondence to: Fernandagouveap@gmail.com

Chickpea crops in southern Saskatchewan have been facing health problems characterized by symptoms
such as chlorosis, wilting, and plant die-off. First noticed in 2019, this issue has affected a wide area,
including the main chickpea-growing region in the province. Crop specialists conducted field soil surveys
in symptomatic and asymptomatic locations; the University of Manitoba analyzed the resulting 143 soil
samples for the presence of plant parasitic nematodes. The pin nematode (Paratylenchus ssp.) was
recovered at unusually high densities and fairly frequently from samples. To investigate if Paratylenchus
were feeding on chickpea, we conducted a growth chamber study utilizing soil samples with high
Paratylenchus density collected from the 2022 survey. Three treatment groups were used: infested soil
with chickpea plants present (CDC-Corrine, 17 reps), infested soil without plants (4 reps), and non-
infested soil with chickpea (3 reps). Infested chickpea soil had an initial Paratylenchus population of 502
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100g dry soil. After 16 weeks, nematodes from soil and roots were extracted by Cobb sugar-flotation.
Paratylenchus and other prominent nematodes were identified to the genus by morphological features
and to species by molecular means (sequencing of the partial 18S, 28S (D2-D3), and ITS (ITS 1 & ITS2)
regions of the rDNA gene). Sequencing showed the species of Paratylenchus to be P. projectus. At the
end of the experiment, chickpea soil and roots in infested pots had a mean of 5,518 Paratylenchus per
100g dry soil (±1180 s.e.), with a reproduction factor of 10.9 (±2.35 s.e.), highlighting chickpeas as an
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excellent host. Without the chickpea host, pin nematode population declined by 96%. However, the plants
did not exhibit any disease symptoms. This study confirms that Paratylenchus projectus, recovered from
Saskatchewan, is a parasite of the tested chickpea variety. Future greenhouse and microplot experiments
are necessary to investigate the effects of Paratylenchus on chickpea health, if other crops are hosts, and
to understand its impact on the chickpea health issue in Saskatchewan.

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