GrainGenes

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 1997 wheat production on the prairies.

 

Virulence of Puccinia triticina in Canada in 1997.

J.A. Kolmer.

Leaf rust of wheat was widespread across the Canadian prairies in 1997. Warm, dry weather facilitated the spread of leaf rust throughout the central plains of North America. Leaf rust severity on susceptible and resistant wheat cultivars was the highest reported in the last 6 years in Manitoba and Saskatchewan. Leaf rust infections were observed as far west as Alberta.

Cultivars with resistance genes Lr13 and Lr16 (AC Barrie, AC Majestic, and Columbus) had higher leaf rust severities compared to past years, because of the increase of leaf rust isolates with virulence to Lr16. Cultivars with Lr34 and Lr16 (AC Domain and AC Splendor) still had very high levels of resistance. In general, the more recently released HRSWs had good to adequate levels of leaf rust resistance, whereas CPS wheats were susceptible.

Forty-seven virulence phenotypes were identified from 362 single pustule isolates of leaf rust in Canada in 1997.

 

 

 

Effect of nitrogen fertilization on wheat protein composition and functionality.

M.I.P. Kovacs, C. Wang, B.D. Fowler, and B.X. Fu.

Some recently developed methods for analysing wheat protein composition have been applied to study the effect of nitrogen fertilization on wheat protein composition and flour functionality. Wheat cultivars with diverse end-use quality were grown at several locations for 3 years at different nitrogen fertilizer levels. The monomeric proteins in flour were extracted selectively with the solvent, 0.3 M NaI-7.5 % 1-propanol. The residue containing all the polymeric proteins (free of monomeric proteins) was extracted further with 50 % 1-propanol and 50 % 1-propanol/1 % DTT to solubilize the smaller and larger sized glutenins, respectively. The total amounts of HMW- and LMW-glutenin subunits in flour were quantified by the 0.3 M NaI-7.5 % 1-propanol extraction procedure, coupled with reversed phase-high performance liquid chromatography of reduced glutenin subunits. The effect of nitrogen fertilization on the ratios of monomeric to polymeric proteins, HMW- to LMW-glutenin subunits, and the size distribution of glutenin were determined.

 

A small-scale bench-top laboratory noodle machine.

M.I.P. Kovacs, G. Dahlke, P. Chen, A. Sarkar, J. Fortin, B.X. Fu, and J.S. Noll.

The success of a wheat breeding program is ultimately evaluated by end-use quality of the grain. End-product evaluation is seldom possible until later stages of a breeding program, because of sample size limitations. A small laboratory noodle machine with dual dough sheeting rolls has been designed and evaluated to produce commercial quality noodles requiring only 10-50 g of flour. Noodle vicoelasticity (NV) and cutting force (CF) obtained from noodles made by the bench-top noodle machine correlated significantly to NV obtained from noodles produced by an Ohtake laboratory noodle machine. Noodle textural characteristics of elasticity, chewiness and firmness, as obtained by sensory methods, are highly predictable by determining NV and CF on noodles made with this bench-top laboratory machine. Dough extensibility, a useful processing quality characteristic, also can be predicted.

 

Evaluation of extra-strong gluten type hexaploid wheats for the production of high quality pasta.

M.I.P. Kovacs, J. Fortin, G. Dahlke, B.X. Fu, J.S. Noll, J. Clarke, K. Preston, and G. Humphreys.

When the price of durum wheat is high or the supply is short, some countries use bread wheats to fulfill the demand for pasta production. A preliminary study showed that wheat with extra-strong gluten had similar cooked gluten viscoelasticity to durum wheat. Thus, four hexaploid wheats, including three extra-strong cultivars and two durum wheat cultivars with high pasta cooking quality were evaluated and compared. Eight western Canadian extra-strong hexaploid wheat samples differing in protein content from 10.5 to 13.5 %, also were evaluated for pasta cooking quality using standard methods. Sensory methods have been used on cooked pasta samples, dried at low and high temperature, to determine chewiness (CH), firmness (FI), and adhesiveness to teeth (AD). The CH value at high temperature and FI at low and high temperature were significantly influenced by protein content. AD was not influenced by protein content, regardless of the drying method used. Cooking quality, as measured by pasta disc viscoelasticity (PDV), SDS-sedimentation test, and mixograph total energy, was highly predictable by protein content regardless of drying method (low, high, and ultra-high temperature). The results indicate that, with this set of samples, the PDV, SV, and the mixograph are useful tests to evaluate rheological properties and predict cooking quality. Pasta cooking quality of extra-strong hexaploid wheats was comparable to that of high quality durum wheats.

 

A large-scale preparation of X-type HMW-glutenin subunits from wheat.

C.Wang, M.I.P. Kovacs, and B.X.Fu.

A method for the separation of x-type HMW-glutenin subunits of common wheat is described. After removing the monomeric proteins, the glutenin subunits were extracted with 40 % ethanol containing a reducing agent. After resting overnight at room temperature(~23 C) in the 40 % ethanol solution, the x-type HMW-glutenin subunits were left in the supernatant after centrifugation. The x-type HMW-glutenin subunits were refined further by the addition of ethanol to a final concentration of 80 % and centrifugation to remove LMW-glutenin subunits. HMW-glutenin subunits (x-type) were extracted from eight Canadian wheat varieties using this protocol. Polyacrylamide gel electrophoresis results show the presence of x-type HMW-glutenin subunits. The procedure was scaled up and permitted the preparation of 30 mg of '90 % pure x-type HMW-glutenin' subunits from 5 g of flour.

 

Mixograph absorption determination using response surface methodology.

M.E. Ingelin and O.M. Lukow.

For the mixograph and other dough mixers, the 'RsMix' system objectively determines water absorption and statistically evaluates its measurement. The RsMix system also exports files to spreadsheet programs to produce response surface plots. The RsMix system is distributed on a single floppy disk that runs under Windows and is network compatible. Each data set analyzed by the RsMix system is composed of an absorption series run at 2 % absorption increments. The system optimizes power input over absorption and time from data input manually or automatically acquired from MixSmart® data files. This data acquisition system has been used for many different types and sizes of mixers, for straight grade and whole wheat flours, and for complete bread formulas. A regression comparing 2 g mixograph to 5 g farinograph absorption had an r2 of 0.81. Mixograph parameters measured at the RsMix system calculated optimum absorption also accounted for 90 % or more of variation in bake absorption, bread volume, and total bread scores.

 

Quality characteristics of glutenin and gliadin proteins of Canada Prairie Spring wheat.

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

Genetic substitution of specific protein genes was made in an effort to improve the agronomically excellent but functionally poor (soft kernel and weak gluten) Alpha 16 breeding line of CPS wheat. Progeny lines were produced containing single doses of specific HMW-glutenin, LMW-glutenin (band 45), or gliadin components typical of the Bigger BSR breeding line. These lines with single substitutions were intercrossed to combine two of the specific additional protein subunits in the Alpha 16 background. Lines were grown at 2-3 locations in western Canada from 1995 to 1997, and the specific protein bands were identified by electrophoresis. The flours currently are being tested for their rheological properties and their suitability for bread and noodle making. The study will help to identify the role of specific protien or protein combination in quality characteristics and also in selecting a CPS wheat line with good agronomical and functional characteristics.

 

Genetic and environmental effects on the protein composition and quality characteristics of 'high-protein' wheat lines.

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

Two sets of 'high-protein' wheat lines were developed at the Cereal Research Centre as a cross between ND643 wheat (source of the T. turgidum var dicoccoides high protein gene) and either AC Minto or Pasqua. Both sets of lines had the same SDS-PAGE pattern for HMW-glutenins but differed in LMW-glutenin subunit and w-gliadin composition. No differences occurred in total flour protein content and dough quality parameters between the two sets. The T. turgidum dicoccoides substitution had a strong effect (P < 0.05) on the total protein content, micro-mixograph work input to peak, and peak force by TA.XT2 texture analyzer. The test location had a very strong effect (P < 0.001) on the total protein content and on all dough quality parameters investigated. Wheats with increased total protein content showed significant decrease of torsial (mixograph development time) and tensile strength (peak force on TA.XT2). Relative distribution of monomeric and polymeric protein in flour was not affected by the type of wheat line, presence of T.turgidum dicoccoides gene, or growing location at P < 0.05 level.

 

The effect of cultivar and growth location on frozen dough blending and baking performance.

C.E.Perron, O.M. Lukow, and T.F. Townley-Smith.

The impact of growth location on the baking quality of doughs frozen for 16 weeks was evaluated using 15 cultivars grown at five locations in western Canada in 1995. The improvement in the frozen dough quality of a weaker flour when the cultivars were used at blending levels of 30 % and 50 % also was considered. Increasing the blend level resulted in increased mixing times, lowered proofing times, and improved loaf quality. The extent of these changes varied with cultivar and growth location. Averaged over the 15 cultivars, growth location significantly affected flour protein content, dough rheological properties, and frozen dough baking quality. However, a strong 'cultivar x growth location' interaction indicated that the effect of growth location on frozen dough baking quality was cultivar dependent. Approximately one-third of the cultivars responded to growth location in a similar manner, as was seen when the effects were averaged over all cultivars. Half of the cultivars gave similar baking results across all growth locations. The results indicated that the baking quality of different cultivars in a frozen dough system or as frozen dough blending flour is not consistent but may vary with changes in growth location.

 

Development of spring wheat germplasm incorporating the Wsm1 gene for resistance to wheat streak mosaic virus.

S. Haber, T.F. Townley-Smith, and E. Czarnecki.

With the continuing increase of winter wheat acreages in recent years in the southeastern Canadian Prairies, WSMV has become an increasingly serious threat to both winter wheat and adjoining or nearby spring wheat crops. Losses as high as 100 % have been observed in popular Canadian HRSW cultivars such as Laura and AC Minto (Haber and Townley-Smith 1993; Haber et al. 1997).

We reported earlier (Haber et al. 1996) on the use of DH technology to exploit the best available WSMV tolerance present in adapted western Canadian germplasm for the development of superior, tolerant breeding lines. In addition to producing adapted germplasm that combined improved WSMV tolerance with acceptable agronomic and quality traits, analysis of three generations of DH lines deriving their WSMV tolerance from BW 155 (an advanced Canadian HRSW line) was uniformly consistent with a model in which tolerance was conditioned by three determinants (Haber et al. 1996; unpublished).

The development of advanced winter wheat lines incorporating the Wsm1 gene for WSMV resistance, but lacking gross quality defects (Seifers et al. 1995), suggested that WSMV-resistant germplasm suitable for the Canadian HRSW class also might be developed using a back crossing regime with suitable, recurring HRSW parents. Although KS95H103 (the winter wheat source of Wsm1) was immune to WSMV infection at temperatures below 25 C when tested with Kansas WSMV isolates (Seifers et al. 1995), it was mildly sensitive to mechanical inoculation with our eastern Prairie WSMV isolate (WSMV-IH) at temperatures as low as 16 C and showed yield losses under WSMV disease pressure that were greater than those observed for the best of the spring wheat DH lines described above (Haber, unpublished).

The first cross was made using KS95H103 as a male parent and AC Elsa as the CWRS female parent. F1 plants were backcrossed to AC Elsa and 68 plants of the BC1F1 generation selected for spring growth habit and resistance to seedling mechanical inoculation with WSMV-IH. Several plants of the F1 generation also were selfed to generate 107 F2 seeds.

Among 68 BC1F1 and 107 F2 plants, 35 and 82, respectively, were highly resistant to seedling infection with WSMV-IH, consistent with expected 1:1 and 3:1 ratios for a single, dominant gene. Unlike KS95H103, the winter wheat source of Wsm1, some of the F2 plants and the sets of their F3 descendants showed no symptoms at all when inoculated as seedlings with WSMV-IH. We will examine succeeding selfed generations of BC2F1 and BC3F1 populations to determine if this apparent, unexpected but desirable, transgressive segregation is maintained. Upon request, small quantities of this germplamsm can be made available to interested wheat workers.

References.

Haber S and Townley-Smith TF. 1993. Developing tolerance to wheat streak mosaic virus in spring wheats for western Canada. Ann Wheat Newslet 39:121-123.

Haber S, Aung T, Townley-Smith TF, and Czarnecki E. 1996. Using doubled haploids (DHs) to incorporate tolerance to wheat streak mosaic virus (WSMV) in western Canadian hard red spring wheat germplasm. Ann Wheat Newslet 42:67-68.

Haber S, Kurtz R, and Moats E. 1997. Wheat streak mosaic in southeastern Saskatchewan and southwestern Manitoba in 1996. Can Pl Dis Surv 77(1):23.

Seifers DL, Martin TJ, Harvey TL, and Gill BS. 1995. Temperature sensitivity and efficacy of wheat streak mosaic virus resistance derived from Agropyron intermedium. Plant Dis 79:1104-1106.

 

Prediction of pasta brownness and durum wheat pigment by near infrared reflectance.

J.S. Noll, M.I.P. Kovacs, G. Dahlke, and D. Prokopowich.

Color and predicted pasta brownness of durum flour, semolina, and wholemeal flour were compared and used to calibrate a scanning NIR instrument. The yellow color of durum wheat as measured by the 'b' value of the Minolta Chromameter is highly correlated to data by solvent extraction. Pasta brownness and yellow color showed high correlation with NIR predictions. Pasta brownness values also were compared to polyphenol oxidase (PPO) activity. Pasta brownness content was several-fold higher in wholemeal flour than in semolina or flour, similar to PPO content. These two enzymatic type tests appear to be easily predicted by NIR in the early stages of the durum wheat breeding program.

 

A rapid falling number test.

M.I.P. Kovacs, J.S. Noll, D. Prokopowich, G. Dahlke, and B.X. Fu.

Flour quality is influenced greatl