ITEMS FROM CANADA

MANITOBA

AGICULTURE AND AGRI-FOOD CANADA

Cereal Research Centre, 195 Dafoe Rd, Winnipeg, Manitoba, Canada, R3T 2M9.

 

Canada's November estimate of 1998 wheat production on the prairies.

Quality characteristics and genetic substitutions of glutenin and gliadin proteins of Canadian prairie spring wheat.

A. Wesley, O.M. Lukow, N. Ames, M.I.P Kovacs, D. Brown, and R. McKenzie.

Genetic improvement of the functional quality of Alpha 16, a CPS wheat line, was continued. Crosses were made between Alpha 16 and Biggar BSR (another CPS wheat line) and progeny inheriting single doses of specific HMW glutenins, a LMW-glutenin subunit (band 45), or gliadin components (BGGL) from Bigger BSR with an Alpha 16 background were evaluated for dough strength properties and baking performance. Wheat lines that contained either the BGGL or the LMW-glutenin subunit 45 exhibited significantly stronger dough-strength properties and higher loaf volumes, indicating the contribution of LMW glutenins and gliadins to the flour quality. Multilocation trials grown in western Canada in 1995 and 1997 showed that the differences in flour quality due to the protein subunits (genetic variation) were consistent in all the environments tested. Individual lines with improved flour quality are being compared for their agronomic performance to evaluate the overall performance. Continuation of the study is underway involving lines developed to contain multiple (double, triple, or quadruple) substitutions of protein subunits.

A micro-extension method using two gram mixograph and the Ta.Xt2 texture analyzer.

J. Suchy, O.M. Lukow, and M.E. Ingelin.

Wheat breeders increasingly rely on micro-scale quality tests suitable for early generation, wheat quality screening. We developed a small-scale dough extension method using the 2-g mixograph and the TA.XT2 texture analyzer. The effects of hook speed and dough water content on the dough extension properties were evaluated. Extensibility of dough prepared at farinograph absorption plus 6 % and micro-mixograph optimized water absorption were positively related to the pup loaf volume, whereas the resistance of dough to extension (rmax) showed a negative relationship with loaf volume. Ranking of wheats according to the dough extensibility on the TA.XT2 were comparable to the relative ranking of wheats based on the loaf volume. The variation in Rmax on the TA.XT2 explained about 80 % of the variation in the mixograph dough development time. The variations in dough extensibility on the Brabender extensigraph and the TA.XT2 instrument explained about 80 and 90 %, respectively, of the variability in the loaf volume for various quality wheats.

Protein composition and quality characteristics of hard red spring wheat lines containing a Triticum turgidum subsp. dicoccoides substitution.

J. Suchy, O.M. Lukow, F. Townley-Smith, and G. Humphreys.

Market demand has influenced the development of HRSW lines with the high-protein gene (pedigrees 'AC Minto*2 / ND643' and 'Pasqua*2 / ND643') at the Cereal Research Centre, Winnipeg. A PCR-based DNA test indicated that 50 % of the lines had a high protein gene from T. turgidum subsp. dicoccoides found in ND643 wheat. Wheats grown over 3 years in various western Canadian locations have shown significant variations in grain and flour protein content. HRSW lines containing the T. turgidum subsp. dicoccoides substitution averaged 1 % higher in grain and flour protein content. The proportion of monomeric and polymeric proteins in flour protein, fractionated in 0.3 m NaI and 7.5 % 1-propanol, was independent of the test location and a T. turgidum subsp. dicoccoides substitution. Absolute amounts of the monomeric and polymeric proteins increased proportionally with the increase in flour protein. Dough rheology of the high-protein lines was evaluated by 10-g mixograph, 50-g farinograph, and micro-extension methods. Triticum turgidum subsp. dicoccoides substitution lines were characterized by higher farinograph absorptions and higher area under curve on the TA.XT2. Loaf volume of the wheats with the T. turgidum subsp. dicoccoides substitution were not significantly different from those without such substitution, but were higher than the loaf volume of CWRSW Katepwa.

PRINCE EDWARD ISLAND

AGICULTURE AND AGRI-FOOD CANADA

Crops and Livestock Research Centre, P.O. Box 1210, Charlottetown, Prince Edward Island, Canada.

H.G. Nass.

The 1998 season.

Cereal grain yields in the maritime region were average to above average. Diseases and pests were not problems in most fields. Winter survival in winter wheat was nearly 100 % in all fields. In our winter wheat plots, S. nodorum prevented successful pollination, and heads produced very little seed. This type of damage by S. nodorum was variety-specific and noticable by blackened areas where saprophytic Alternaria had invaded dead tissue. Yields were excellent despite this damage. Because of the high grain yield, there were problems in achieving the sufficiently high protein content (12.5-13.5 %) acceptable for milling. Spring wheat varieties developed in western Canada tend not to have this problem, because they are lower yielding, the protein is more concentrated in the grain, and they were developed from germ plasm that produces more consistent, high-quality milling wheat than varieties developed in Europe, the U.S., and eastern Canada. Spring wheat varieties from western Canada are quite consistent in achieving the required protein content from year-to-year, whereas varieties from other sources lack this consistency. Results from preliminary studies indicate that to produce the required protein content in the grain, three applications of nitrogen may be required for varieties not developed in western Canada and at levels that may not always be economical. The lower-yielding varieties from western Canada seem to achieve the desired protein level with only two nitrogen applications.

Breeding for resistance to Fusarium head blight.

Fusarium head blight is a serious problem in all of eastern Canada. Progress in developing material with improved resistance to FHB has been very slow. Crosses with Nuy Bay, Wuhan, and Sumai-3 have produced populations with a substantial improvement in FHB resistance as shown in lower head and seed infections and DON levels. Although lines with Sumai-3 are later maturing and have a tendency to be susceptible to powdery mildew, they produce larger heads and more grain yield. Thus, Sumai-3 is one of the preferred sources of resistance by many breeders including ourselves. The lack of diversity from not using more sources of resistance could present a problem in the future, if the Fusarium fungus overcomes the resistance found in Sumai-3.

Publications.

Nass HG, Johnston HW, Blatt CR, Atlin GN, Rodd AV, and Walker DW. 1997. AC Wilmot spring wheat. Can J Plant Sci 77:655-656.

Nass HG, Johnston HW, Atlin GN, Mellish D, and Walker DW. 1998. AC Norboro spring wheat. Can J Plant Sci 78:115-118.