Page 259 - PC2019 Program & Proceedings

PLANT CANADA 2019

P91. Major genomic regions underlying seed size, protein and sucrose in food-grade soybeans
*
Torabi, S. ; R. Whaley; M. Eskandari
University of Guelph

The production of soy-based food products, such as tofu and soymilk, requires specific physical and
chemical characteristics of the soybean seed. Identification of quantitative trait loci (QTL) associated with
value-added traits, such as increased seed protein and sucrose concentrations as well as large seed size,
could accelerate the development of competitive high-protein soybean cultivars for the Canadian food-
grade market through marker-assisted selection (MAS). The objectives of this study were to identify and
validate QTL associated with seed protein and sucrose concentrations, seed size, and yield in two high-
protein recombinant inbred line (RIL) populations. The two RIL populations were derived from crosses
between the high-protein cultivar AC X790P (49% protein, dry weight basis), and two high-yielding
commercial cultivars, S18-R6 (41% protein) and S23-T5 (42% protein). The RIL populations were grown
2
in five different environments in southwestern Ontario. In total, 14 large-effect QTL (R >10%) associated
with seed protein concentration were identified with potential use in MAS. Six of these protein-related
QTL were also co-localized with the QTL associated with seed sucrose concentration or size. Major
protein-related QTL did not show significant impacts on seed yield QTL in these populations. The
favorable alleles were sourced from both parental cultivars. The putative QTL identified in this study are
desirable candidates for MAS programs, and could be utilized to develop new soybean cultivars for
specific soy-based food products.

Sepideh Torabi (storabi@uoguelph.ca)

P92. Mapping cold hardiness in tetraploid garden roses (Rosa x hybrida)
2
1
*1
3
Rouet, C. ; E. Lee ; K. Tanino ; D. Somers
1 University of Guelph
2
University of Saskatchewan
3
Vineland Research and Innovation Centre
Canadian roses such as the ‘Explorer’ series are known worldwide for their exceptional cold hardiness.
While cold hardiness exists in wild roses, it is lacking in modern garden roses and limits their area of
cultivation. Releasing cold hardy varieties is necessary to meet the demand for low maintenance roses but
breeding for cold hardiness is difficult due to linkage drag and weather-dependant field assessments. Cold
hardiness in roses is highly heritable and under the control of few major genes. High density SNP maps
were available for both parents of a tetraploid population derived from an ‘Explorer’ rose. Progeny were
planted in two locations in 2018 (Elora, ON, CA; Saskatoon, SK, CA) and evaluated for winter damage,
spring regrowth and vigour in spring 2019. The same set of progeny were examined by artificial freezing
where electrolyte leakage was measured on stem sections as an index of freezing resistance. Preliminary
mapping analyses revealed a QTL for Elora winter damage on chromosome 2 and a QTL for artificial
freezing resistance on chromosome 3. Winter damage data will be recorded again in 2020 and data from
all four environments will be used to study the heritability of the cold-related traits and validate the QTLs
in multiple environments. Candidate genes will be investigated. Resequencing data of the parental lines
will be used to search for polymorphism in the candidate genes.

Cindy Rouet (cindy.rouet@vinelandresearch.com)

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