In the last decade, the cabbage seedpod weevil (Ceutorhynchus obstrictus (Marsham)) has become a major insect pest of canola (Brassica napus L.) in Canada reducing seed yields up to 35%. Therefore, the benefits of developing weevil resistant germplasm to canola breeders and the industry would reduce input costs, pesticide use, environmental degradation and increase yield. Yellow mustard (Sinapis alba L.) is resistant to C. obstrictus (CSPW), although the exact mechanism is not known (McCaffrey et al. 1999). A unique canola population was generated at the University of Guelph from a cross between B. napus and S. alba through embryo rescue and backcrossed to canola several times prior to double haploid (DH) production. Approximately one-half of this DH population had canola quality glucosinolate concentration (\16 lmol/g) and was used for further breeding. The hypothesis was that some DH progeny from this cross inherited resistance to CSPW from S. alba. Weevil infestation levels were assessed for the B. napus 9 S. alba BC2 and BC3 DH populations in the field over 7 years in Alberta where weevil pressure is strong to establish the resistant or susceptible status of these lines. The basic objectives for this study were to confirm field resistance in the B. napus 9 S. alba germplasm in Ontario and to identify any biochemical markers associated with resistance/susceptibility. Canola doubled haploid lines derived from BC2 or BC3 families were field screened for resistance (R) followed by chemical analysis of glucosinolates to detect biochemical polymorphisms correlated with CSPW resistance using High Performance Liquid Chromatography (HPLC). Two polymorphic peaks were found, one each, from extracts of upper cauline leaves and Stage 3 pod seed, with retention times of *23 and 19 min, respectively. These HPLC peaks consistently correlated with larval infestation data and the peak differences between R and S DH lines were significant. Therefore, these two peaks can be considered as biochemical markers in this breeding germplasm and may play a role in rapid and early detection of CSPW resistance.

Soybean seeds [Glycine max (L.) Merrill] are a major source of tocopherols that provide many human health benefits including decrease in lung cancer risk and osteoporosis. The objectives of this study were: (i) to determine the impact of genotype, environment, and genotype × environment on soybean seed tocopherols and (ii) to evaluate relationships between agronomic traits and tocopherols. Seventy‐nine recombinant inbred lines (RILs) from the cross OAC Bayfield × OAC Shire were grown in three field locations in southern Ontario, Canada, in 2009 and 2010. Agronomic and seed quality data were collected in each location. Significant differences (P < 0.001) for the α‐, γ‐, δ‐, and total tocopherol concentrations were found in the seed of RILs using combined ANOVA for 2009 and 2010. Of the two parental lines, OAC Bayfield accumulated more total tocopherol at most environments. Genotype, location, and year differences were significant as well as genotype × location, location × year, and line × year interactions. Broad‐sense heritability estimates were 0.38 for α‐, 0.47 for γ‐, and 0.35 for δ‐tocopherol. None of the agronomic traits were consistently correlated with any of the tocopherol components; however, oil and protein concentration were correlated to some tocopherols in some of the environments. The wide range in values for α‐, γ‐, δ‐, and total tocopherols among the RIL population that exceeded both parents provided evidence for transgressive segregation. Our results suggest that soybean producers should take locations and genotypes into account when growing soybean for enhanced tocopherol production.

Soybean (Glycine max [L.] Merr.) is cultivated primarily for its protein and oil in the seed. In addition, soybean seeds contain nutraceutical compounds such as tocopherols (vitamin E), which are powerful antioxidants with health benefits. The objective of this study was to identify molecular markers linked to quantitative trait loci (QTL) that affect accumulation of soybean seed tocopherols. A recombinant inbred line (RIL) population derived from the cross ‘OAC Bayfield’ × ‘OAC Shire’ was grown in three locations over 2 years. A total of 151 SSR markers were polymorphic of which a one‐way analysis of variance identified 42 markers whereas composite interval mapping identified 26 markers linked to tocopherol QTL across 17 chromosomes. Individual QTL explained from 7% to 42% of the total phenotypic variation. Significant two‐locus epistatic interactions were identified for a total of 122 combinations in 2009 and 152 in 2010. The multiple‐locus models explained 18.4–72.2% of the total phenotypic variation. The reported QTL may be used in marker‐assisted selection (MAS) to develop high tocopherol soybean cultivars.

No abstract

No abstract