W. G. Legge

AC Metcalfe barley

AC Metcalfe is a two-row spring malting barley (Hordeum vulgare L.) cultivar widely adapted to western Canada with high yield, good agronomic traits, moderate disease resistance and excellent malting quality. Of note are its good resistance to loose smut and moderate resistance to Fusarium head blight. Key words: Malting barley, Hordeum vulgare L., cultivar description, yield, disease resistance, malting quality

The genetic basis of scald resistance in western Canadian barley cultivars

SummaryThe genetic basis of resistance to scald (Rhynchosporium secalis) within barley breeding populations is poorly understood. The design of effective genetically based resistance strategies is predicated on knowledge of the identity of the resistance genes carried by potential parents. The resistance exhibited by a broad selection of western Canadian barley lines was investigated by evaluating their reactions to five R. secalis isolates. Results were compared to the resistance exhibited by previously characterized lines. This comparison, combined with pedigree analysis indicated that there are two different resistance genes present inwwestern Canadian cultivars. These genes were shown to be independent through analysis of a segregating population derived from a cross between Falcon and CDC Silky. This evidence, along with observed linkage of the gene in CDC Silky with an allele specific amplicon developed for a Rhynchosporium secalis resistance locus on chromosome 3, provides evidence that the gene in Falcon is the Rh2 gene derived from Atlas, and the gene (s) in CDC Silky is located within the Rh/Rh3/Rh4 cluster and is similar to the Rh gene in Hudson.

Progress in breeding for resistance to fusarium head blight in barley

In western Canada, from 2000 to the spring of 2003, much of the breeding effort to improve resistance of barley (Hordeum vulgare) to fusarium head blight (FHB) was conducted through a collaborative project supported by a number of funding agencies. The main results of this 3-year project were briefly discussed in the present study, with the conclusion that this project has laid the foundation for developing new barley cultivars with improved resistance to FHB. A new 3-year project with an increased national focus was initiated in the spring of 2003, with funding from the Western Grains Research Foundation and Agriculture and Agri-Food Canadas Matching Investment Initiative program. A brief description of the new project and an update on progress in 2003 is presented in this study. The new project will pursue most of the objectives of the former project, with one of the important additions being access to the FHB nursery at Charlottetown, Prince Edward Island. Although more deoxynivalenol analyses will be conducted using enzymed-linked immunosorbent assays for the new project, currently available capabilities for testing deoxynivalenol levels remain a major constraint in barley breeding. In conclusion, progress is being made in improving resistance to FHB in barley, but it will be a long-term effort.

Deoxynivalenol levels and chemotype frequency in barley cultivars inoculated with two chemotypes of Fusarium graminearum

Abstract Corn kernels colonized by Fusarium graminearum were spread between lines of barley (Hordeum vulgare) in an irrigated Fusarium head blight (FHB) nursery at a 2 : 1 ratio of isolates producing 15-acetyldeoxynivalenol (15 ADON) to isolates producing 3-acetyldeoxynivalenol (3 ADON) (in 2008) or 1 : 1 ratio (in 2009, 2010). In 2008, it was the first use in this field of a 3 ADON isolate after 9 years of artificial inoculation with exclusively 15 ADON isolates. Sets of three 2-row and three 6-row cultivars were used as checks throughout the nursery, representing a range of susceptibility to FHB. Composites of these cultivars were prepared and analysed for per cent F. graminearum infection, chemotype frequency and levels of deoxynivalenol (DON), 3 ADON and 15 ADON. Seed infection by F. graminearum ranged from 83.5% (2009) to 98.5% (2010), with little difference across the nursery. In 2008, the chemotype distribution of F. graminearum and DON levels on infected kernels showed a several-fold difference from the eastern side (67% 3 ADON isolates and 46 ppm DON) to the western end of the field (16% 3 ADON isolates and 13 ppm DON), but not in the subsequent 2 years. In both 2009 and 2010, the 3 ADON chemotype was recovered from only 18% and 13% of the seeds, and overall average DON levels were 18 ppm and 24 ppm, respectively. In 2008, the highest DON and 3 ADON levels were associated with the highest frequency of the 3 ADON chemotype. In all years, the recovery of isolates did not reflect the ratio of the initial inoculum, suggesting that other factors influenced the ultimate infection of the seed. However, the relative relationship among the barley cultivars was consistent throughout all 3 years: DON levels were much lower in the most resistant cultivars compared with the most susceptible cultivars in all years and composites. Genotypic response to DON accumulation did not show strong interaction with 3 ADON frequency, suggesting that the underlying genetic resistance of the barley cultivars is cross-applicable between chemotypes.

Genetic Variation and Relationships of Pedigree-Known Oat, Wheat, and Barley Cultivars Releaved by Bulking and Single-Plant Sampling

Applications of bulking procedures have played an increasingly important role in molecular characterization of plant germplasm, but little attention has been made to address the effectiveness of detecting genetic variation and inferring genetic relationships via bulking. An analysis was performed here to compare the genetic variation detected and genetic relationships inferred via bulking and single-plant sampling of five oat (Avena sativa L.), wheat (Triticum aestivum L.), and barley (Hordeum vulgare L.) cultivars with known pedigrees using amplified fragment length polymorphism (AFLP) markers. Three AFLP primer pairs were applied to screen one bulk and eight single-plant samples of each cultivar and up to 140 AFLP bands were scored for each sample. Analyses of these AFLP data showed bulking revealed AFLP variation up to 21.4% less than corresponding single-plant sampling for these crop species and also introduced up to 2.2% upward and 5.1% downward biases in detecting AFLP variations for each cultivar. The genetic relationships inferred by bulking using the Dices coefficient, the simple matching coefficient, and the Jaccards coefficient were largely the same, but differed from those in single-plant samples employing average Dices coefficient, average simple matching coefficient, and AMOVA-based distance method. All of the inferred genetic relationships were not congruent to the known pedigrees. Clearly, substantial biases could exist in detection of AFLP variation and in inference of genetic relationships from bulk samples, even for closely related germplasm, and more efforts to assess the effectiveness of bulking in inferring genetic variation and relationships are needed for more informative molecular characterization of plant germplasm.

Evaluation of inoculation methods on infection and deoxynivalenol production by Fusarium graminearum on barley

Nineteen barley (Hordeum vulgare) genotypes representing various reported levels of resistance to fusarium head blight (FHB) were subjected to three inoculation methods (point or spray inoculation in the greenhouse, and grain spawn in a field nursery) and rated for phenotypic symptoms and deoxynivalenol (DON) content. Using all three inoculation methods in replicated experiments, seven genotypes were ranked among the more resistant lines: “Chevron”, “CI4196”, “Harbin”, “Island”, “Svansota”, “TR04283”, and “Zhedar #1”. “Stander” was consistently more susceptible. Significant differences for phenotypic symptoms among barley genotypes (P < 0.0001) were found using all three inoculation methods. Significant differences in DON levels among the barley genotypes (P < 0.0001) were observed for only one point-inoculation experiment. A positive correlation between DON levels and FHB ratings was found using point inoculation (r = 0.719) (one replicate) and grain spawn inoculation in nursery trials (r = 0.678). All three inoculation methods allowed for the rating of FHB reactions among the barley genotypes; however, indoor spray inoculation was the most reproducible method for phenotypic evaluation. Indoor spray inoculation mimics natural infection while controlling environmental influences allowed for the broadest discrimination of resistance among the 19 barley genotypes.

Identification of isolate specific sources of scald resistance in Turkish barley (Hordeum vulgare) accessions

Disease reactions to specific Rhynchosporium secalis isolates from western Canada were characterized on forty Turkish Hordeum vulgare accessions. One accession, MEH151-1, exhibited resistance against isolate WRS1860 and was also resistant to isolates WRS1493 and WRS1824 which were avirulent to the Rh gene. A related line, MEH151-2 exhibited resistance to WRS1493 but not to WRS1860. Crosses between both MEH151-1 and MEH151-2, and the susceptible cultivar, Harrington, were used to demonstrate a linkage between resistance to WRS1493 and an allele specific amplicon, Falc666. Resistance to WRS1860 imparted by MEH151-1 was mapped to the other side of the Falc666 locus. Falc666 was previously shown to be located near the centromere on the long arm of chromosome 3. Characterization of the genetic basis for the scald resistance phenotype exhibited by these Turkish accessions, coupled with the identification of marker linkages, provides evidence for genetic variation in scald resistance in this chromosomal region.

AAC Connect barley

Abstract: AAC Connect is a hulled two-row spring malting barley (Hordeum vulgare L.) cultivar widely adapted to western Canada. Developed from the cross TR04282/BM9831D-229 made in 2004, AAC Connect was evaluated in the Western Cooperative Two-Row Barley Registration Test (2012–2013) and the Collaborative Malting Barley Trials (2013–2014) conducted by the malting and brewing industry before being registered in 2016. AAC Connect has a desirable combination of agronomic, malting quality, and disease-resistance traits including lower deoxynivalenol accumulation.

Detection of Incipient Germination in Malting Barley with a Starch Viscosity Method and a Proposed Ethanol Emission Method

The risk of germination loss during storage in two-row malting barley can be reduced by identifying grain lots that have undergone incipient germination (IG) during harvest. A method based on starch viscosity that utilizes a Rapid Visco Analyzer (RVA) is currently available for IG analysis. A new potential method, based on the measurement of ethanol emission (EE) from whole barley, may be more efficient and less expensive than the RVA procedure. Three storage experiments were performed: experiments 1 and 3 at 25°C and 80% rh, and experiment 2 in unheated, uninsulated buildings. Decline in germination energy (GE) varied from <1% to about 80% during storage. In experiments 1 and 3, R2 for GE loss (expressed as [weeks to 5% loss of GE]0.2) versus EE was 0.76 in both cases, whereas R2 for GE loss versus RVA viscosity was 0.64 and 0.68, respectively. In experiment 2, the greatest loss of GE was associated with high temperatures and relative humidity in July and August. EE performed as well as RVA in the predic...