Page 128 - Plant Canada 2024 Proceeding

PLANT CANADA 2024

during periods of relatively low soil water content was linked to ‘tight’ stomatal behavior (i.e., efficient
transition from onset to full stomatal closure) and ‘early’ leaf roll (i.e., reductions in flag leaf width).
Moreover, leaf hydration status (ΘRWC) marked the onset of drought-induced losses in kernel weight in all
three cultivars. Among cultivars, ‘Superb’ was most successful in employing these strategies which also
prolonged the onset of severe leaf dehydration under drought to a soil relative water content (i.e., % of
field capacity) as low as 36% (defined as threshold RWC); ‘Stettler’ at a RWC of 48%, and ‘AAC Viewfield’
at a RWC of 51%. Moreover, RWC marked the onset of drought-induced losses in kernel weight in all
three cultivars. Leaf epicuticular waxes exhibited differences in chemical composition between cultivars,
which will be discussed in the context of leaf water loss beyond stomatal regulation under drought. In
conclusion, Canadian hard red spring wheat lacks OA but both leaf stomatal behavior and leaf rolling aid
in securing leaf hydration status and kernel weight under drought.

[O53] ENHANCING PROTEIN CONTENT IN BRASSICA NAPUS: GENETIC INSIGHTS AND
BREEDING IMPLICATIONS. Harmeet S. Chawla , Mohamed S. Youssef , Sean Walkowiak , and Robert
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W. Duncan . Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, R3T 2N2,
Canada; and Canadian Grain Commission, Winnipeg, MB R3T 6C5, Canada
2
Correspondence to: Harmeet.Chawla@umanitoba.ca

Brassica napus, commonly known as canola, is a vital oilseed crop extensively cultivated for its high-
quality canola oil. However, oil extraction generates approximately 1.2 million tons of canola meal
annually as a by-product. Despite the increasing popularity of plant-based protein and the rising demand
for alternative protein sources, the breeding of canola cultivars with enhanced protein content has been
limited, primarily due to the lack of financial incentives. Understanding the genetic factors that influence
protein content in B. napus is crucial for meeting this growing demand. This study aimed to identify
genetic polymorphisms associated with protein content in B. napus. We focused on pinpointing the critical
candidate genes, as well as the single nucleotide polymorphisms (SNPs) and structural variations (SVs)
that play significant roles in regulating protein content in this crop species. Our research identified 24
quantitative trait loci (QTL) associated with protein content across two double haploid mapping
populations. Notably, a QTL located on chromosome C09 was consistently detected in three different
environments within both populations. By anchoring the genetic markers flanking this QTL region onto the
Westar genome assembly, we identified a 7 Mb region on chromosome C09 containing 1079 protein-
coding transcripts. Integrating QTL data with long-read PacBio HiFi sequencing data from the parental
lines of the two bi-parental populations, we discovered a potential candidate gene that may significantly
contribute to protein synthesis in B. napus. Our findings underscore the complexity of the genetic
regulation of protein content in B. napus and provide valuable insights for future research aimed at
expanding the end-use of this essential crop. The integration of genetic data with advanced sequencing
technologies presents a powerful approach to unravelling the genetic basis of complex traits in crops,
paving the way for more targeted and efficient crop breeding programs.

[O54] PARTICIPATORY PLANT BREEDING TO INCREASE DIVERSITY AND RESILIENCE: A CASE
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STUDY OF CANADIAN WHEAT. Michelle Carkner and Martin Entz . Department of Plant Science,
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University of Manitoba, 66 Dafoe Road, Winnipeg, MB, Canada, R3T 2N2
Correspondence to: michelle.carkner@umanitoba.ca

Numerous studies have shown that greater biodiversity enhances functioning in cropping ecosystems, yet
modern breeding programs focus on uniformity. This contradiction raises the question “Will uniform crop
varieties be resilient in the face of increasingly unpredictable weather events and seasonal extremes
brought on by climate change?” Our project is based on the premise that diversity offered by populations
of plants will lend greater climate resilience than genetically uniform genotypes in contrast to the current
Canadian crop registration system and global market demands for uniformity. Secondly, we hypothesized
that engaging Canadian farmers in the early selection phase of plant breeding will increase the level of
“effective diversity” within wheat genotypes.

In this work, we adopted a decentralized/target environment approach where early generation selection
(F3 to F6) took place on farms with farmers directly involved in the selection. By working specifically with
organic farmers, we ensured that nutrients would be supplied biologically (legumes, manures, etc.) rather
than synthetic fertilizers that exacerbate agriculture’s reliance on fossil fuels.

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