Page 316 - PC2019 Program & Proceedings

PLANT CANADA 2019

TOPIC 23: Plant-Biotic Interactions (Posters P205-P211)

P205. Foliar selenium application for controlling fungal diseases in greenhouse
Fofana, B.; A. Somalraju; J. McCallum; R. Peters; D. Main
Charlottetown research and development centre

Potato is the third most important food crop consumed globally. However, potato yield and production are
compromised by diseases including late blight, the most devastating potato disease. Despite the
availability of effective fungicides for controlling late blight in conventional production systems,
fungicide resistance has become common and not many options are available for organic production
systems. Selenium as a mineral micronutrient is essential to human and animal health in trace amounts, is
widely used for crop and livestock biofortification and its roles for protection against fungal infection and
aphid feeding has been purported. In this study, the effect of selenium on late blight was assessed in
potato and tomato plants and its mode of action determined in vitro. Our results showed that foliar
selenium applications increase the production of secondary metabolites in potato leaves and tubers and
reduce the late blight severity and incidence in potatoes and tomatoes. Selenium’s disease control effect
was attributed to its direct toxicity to a wide range of pathogenic fungi at level as low as 2 ppm. The data
will be presented and discussed in relation with the potential use of selenium as disease control agent in
greenhouse horticultural crops while contributing to bio fortify crops.

Bourlaye Fofana (bourlaye.fofana@canada.ca)

P206. Diversity of rhizosphere microbiomes in pea plant with and without root rot
1
1
1
Hossain, Z. ; M. Hubbard ; L. Bainard ; Y. Gan
2
1 Swift Current Research and Development Centre
2
Agriculture and Agri-Food Canada

Root and rhizosphere microbiomes are affected by crop growth environment and are closely associated
with plant health. Here we studied the impact of root rot on pea (Pisum sativum L.) root and rhizosphere
microbiomes using amplicon metagenomic sequencing. At early flowering, diseased and healthy samples
were collected from nine fields in Saskatchewan, Canada. Bacterial and oomycete alpha-diversity (i.e.,
richness, Shannon index) was higher in diseased root and rhizosphere samples than their healthy
counterparts, while fungal diversity was unaffected. The community structure of the root and rhizosphere
microbiomes were also significantly affected by the health status of the plants, with bacterial communities
exhibiting the strongest differences between healthy and diseased samples. Overall, the microbiome
structure of diseased samples were more predictable than healthy samples (i.e., higher number of
indicator species: 42 diseased vs. 11 healthy). In addition, the diseased core microbiome included a
greater number of taxa compared to the healthy core microbiome. Our results show key differences
between the microbiomes of healthy and diseased pea. Further research into determining whether
differences in the microbiome influence pea susceptibility to root rot, as opposed to root rot inducing
changes in the microbiome, are merited. Combined with the current results, such information could help
assess root rot risks and/or develop management strategies to improve the potential of agricultural soils to
suppress disease.

Yantai Gan (yantai.gan@canada.ca)

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