Page 26 - CSHS 2022 Book of Abstracts - 2022-08-22 web version

CSHS 2022 Conference

(FP.3) Apple root endophytes as biological control agents of Apple Replant Disease
Maria Roy 1,2* , Shawkat Ali , Allison K. Walker
1
2
1. AAFC, Kentville, NS; 2. Department of Biology, Acadia University, Wolfville, NS
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Apple replant disease (ARD) occurs when new apple trees are planted in soil that was previously used to grow
apples or related plants and results in a reduction of tree vigour and fruit yield, as well as delayed growth and fruit
bearing. Usage of chemical fumigants is becoming increasingly restricted, creating a need for eco-friendly alternative
control methods for ARD. Endophytes are microorganisms that live in association with plants without causing
disease and can protect against pathogens by secreting antimicrobial compounds, through direct competition with
the pathogens for space and nutrients or upregulation of the plant’s defenses. We hypothesize that mature, healthy
apple roots harbour beneficial fungal endophytes that contribute to their tolerance/resistance to ARD-causing
pathogens. We isolated fungal endophytes from healthy apple tree roots and evaluated a diverse panel of these
endophytes for in vitro antagonism against ARD-causing agents using dual culture competition assays. Endophytes
were screened against Pythium ultimum and Rhizoctonia solani; two pathogens that have been associated with ARD.
Each endophyte was given an inhibition score against each pathogen and the type of interaction was categorized.
Interactions between endophyte and pathogen included mycelial deadlock between the competing endophyte and
pathogen, partial or complete overgrowth of endophyte over pathogen, or a deadlock between the endophyte and
pathogen without contact. Data on competition of these endophytes in dual culture assay with two ARD-causing
pathogens will be presented. Endophytes with the highest antagonistic effects on ARD-causing pathogens in vitro
will be selected for further testing.

(FP.4) Bioactive phenolic compound profiling of prairie berries
Chamali Kodikara 1,2,3 , Nandika Bandara , Thomas Netticadan , Champa Wijekoon 1,2,3*
1,2
3
1. Agriculture and Agri-Food Canada, Winnipeg, MB; 2. Canadian Centre for Agri-Food Research in Health and
Medicine, Winnipeg, MB; 3. Department of Food & Human Nutritional Sciences, University of Manitoba
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Traditional berries including Vitis riparia (wild grape), Prunus virginiana L (chokecherry), Ribes hirtellum
(gooseberry) and Amelanchier alnifolia L (Saskatoon berry), are cold hardy fruits consumed by prairie Canadians,
including the indigenous population and are widely distributed in the prairie provinces. Polyphenols are considered
as an important group of bioactive molecules present in the berries that occur as plant secondary metabolites. Due
to the presence of high antioxidant capacities of polyphenols, there has been an increasing interest in identifying
their potential health benefits corresponding to their presence in food. Recent findings have shown that diets rich in
antioxidants protect humans against degenerative diseases such as diabetes, cancer, and neurodegenerative and
cardiovascular diseases. This research aimed to examine the phenolic compound composition of four prairie berries
and thereby identify potential bioactive compounds and metabolite markers unique to each crop using High-
Performance Liquid Chromatography (HPLC). Our results showed that wild grapes were rich in phenolic compounds
such as resveratrol, while gooseberries were rich in isoquercetin and paracoumaric acid. Moreover, Saskatoon
berries were rich in chlorogenic acid and quercetin. In addition, rutin-trihydrate and chlorogenic acid were
identified as the most abundant phenolic compounds in chokecherry. Further studies are needed to profile and
quantify the other available phenolic compounds in these underutilized prairie berries.

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