AAC Awesome special purpose spring wheat

AAC Awesome is a high yielding spring wheat (Triticum aestivum L.) cultivar eligible for the Canada Western Special Purpose (CWSP) wheat class. Based on 29 site-years of testing over 3 years in the General Purpose Wheat Registration trial (2013–2015), AAC Awesome yielded 14% more grain than AC Andrew, and surpassed yields of Sadash, 5702PR, and Pasteur by 12%, 22%, and 9%, respectively. AAC Awesome had similar maturity, was slightly taller, had higher test weight and larger kernels as compared to AC Andrew. AAC Awesome had excellent levels of resistance to the prevalent races of leaf, stem and stripe rust. It expressed an intermediate level of resistance to Fusarium head blight (FHB), common bunt and loose smut. It also expressed tolerance to the orange wheat blossom midge. AAC Awesome is eligible for grades of Canada Western Special Purpose Wheat class.

A laboratory method for mass rearing the orange wheat blossom midge, Sitodiplosis mosellana (Diptera: Cecidomyiidae)

Orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), has been successfully reared in the laboratory for more than 20 years in Winnipeg, Manitoba, Canada. The rearing method has been developed to the point where it efficiently produces large numbers of wheat midge continuously under laboratory conditions for use in experiments on wheat midge biology and for screening wheat lines for crop resistance. Adult survival was extended by providing high humidity, and oviposition was increased by simulating natural dawn and dusk conditions and by supplying preflowering spring wheat to adults. Preventing desiccation of the wheat midge larvae in the wheat spikes before overwintering in soil and providing optimal cold conditions for a long enough period to break larval diapause enabled successful adult emergence. We provide data to facilitate the coordination of timing of wheat midge emergence from diapause with the wheat susceptible period. The method can be readily scaled up for screening many lines for resistance or scaled down for small experiments. Here, we report details of the rearing method so that others can implement it for research on the management of this internationally important pest.

Functional Analysis of Odorant-Binding Proteins 12 and 17 from Wheat Blossom Midge Sitodiplosis mosellana Géhin (Diptera: Cecidomyiidae)

The wheat blossom midge Sitodiplosis mosellana, one of the most disastrous wheat pests, depends highly on olfactory cues to track suitable plants. To better understand the olfactory recognition mechanisms involved in host selection, in the present study we cloned two S. mosellana adult antenna-specific odorant binding protein (OBP) genes, SmosOBP12 and SmosOBP17, and evaluated bacterially expressed recombinant proteins for their selectivity and sensitivity for host wheat volatiles using the fluorescence-based ligand binding assay. The results showed that both SmosOBPs effectively bound alcohol, ester, ketone, and terpenoid compounds. Particularly, SmosOBP12 had significantly higher affinities (Ki < 10.5 μM) than SmosOBP17 (Ki2 > 0.1 μM) to 3-hexanol, 1-octen-3-ol, D-panthenol, 3-carene, (Z)-3-hexenylacetate, hexyl acetate, methyl salicylate, heptyl acetate, and ethyl heptanoate. Consistently, S. mosellana females were attracted to all these chemicals in a behavioral assay using Y-tube olfactometer. SmosOBP12 also bound aldehyde, but neither bound alkanes. Notably, SmosOBP12 exhibited strong affinity to ocimene (Ki = 8.2 μM) that repelled S. mosellana. SmosOBP17, however, was insensitive to this compound. Taken together, our results indicate that SmosOBP12 may play a greater role than SmosOBP17 in perceiving these biologically active plant volatiles.

AAC Succeed Durum Wheat

AAC Succeed durum wheat (Triticum turgidum L. subsp. durum (Desf.) Husn.) is adapted to the durum production area of the Canadian prairies. AAC Succeed carries the Sm1 gene which confers antibiosis-based resistance to orange wheat blossom midge [Sitodiplosis modellana (Gehin)]. Averaged over three years, AAC Succeed yielded significantly more grain than Strongfield (7%) and AC Navigator (21%). AAC Succeed had a protein concentration significantly higher than Brigade and AC Navigator and similar to Strongfield. AAC Succeed had significantly stronger straw as measured by lodging score than Strongfield and similar to Brigade. AAC Succeed is eligible for grades of Canada Western Amber Durum, has low grain cadmium concentration, and it has higher yellow pigment concentration than the check cultivars.