Forty-eight spring barley genotypes were evaluated for deoxynivalenol (DON) concentration under natural infection across 5 years at Harrington, Prince Edward Island. These genotypes were also evaluated for Fusarium head blight (FHB) severity and DON concentration under field nurseries with artificial inoculation of Fusarium graminearum by the grain spawn method across 2 years at Ottawa, Ontario, and one year at Hangzhou, China. Additionally, these genotypes were also evaluated for FHB severity under greenhouse conditions with artificial inoculation of F. graminearum by conidial suspension spray method across 3 years at Ottawa, Ontario. The objective of the study was to investigate if reactions of barley genotypes to artificial FHB inoculation correlate with reactions to natural FHB infection. DON concentration under natural infection was positively correlated with DON concentration (r = 0.47, P < 0.01) and FHB incidence (r = 0.56, P < 0.01) in the artificially inoculated nursery with grain spawn method. Therefore, the grain spawn method can be used to effectively screen for low DON. FHB severity, generated from greenhouse spray, however, was not correlated with DON concentration (r = 0.12, P > 0.05) under natural infection and it was not correlated with DON concentration (r = -0.23, P > 0.05) and FHB incidence (r = 0.19, P > 0.05) in the artificially inoculated nursery with grain spawn method. FHB severity, DON concentration, and yield were affected by year, genotype, and the genotype × year interaction. The effectiveness of greenhouse spray inoculation for indirect selection for low DON concentration requires further studies. Nine of the 48 genotypes were found to contain low DON under natural infection. Island barley had low DON and also had high yield.

Fusarium head blight (FHB) is a destructive disease of barley (Hordeum vulgare L.) in many countries. The disease can result in mycotoxin contamination such as deoxynivalenol (DON) in the grain. The objective of this study was to determine if black barley is more resistant to DON accumulation than yellow barley as the former contains a high level of phenolic compounds. In one experiment, 100 recombinant inbred lines (RILs) were derived from each of the two barley crosses: AC Klinck/CH9403-2 and AC Legend/CH9403-2 with half of them being black and the other half yellow. These lines along with their parents were evaluated for resistance to DON accumulation under natural infection conditions at Harrington (Prince Edward Island) for 3 yr (2005-2007). They were also evaluated for resistance to FHB incidence and DON accumulation under artificial inoculation conditions at Ottawa (Ontario) in 2005 and 2006 and at Hangzhou (China) in 2005-2006. Black RILs on average contained 17 to 59% less DON than yellow RILs under natural conditions in both crosses in two tests. Black RILs had 2 to 20% lower FHB incidence than yellow RILs in both crosses in two tests and contained 16 to 18% less DON in one test. In another experiment, 26 hulless accessions were evaluated at Ottawa in 2011 and 2012. Black accessions on average contained 53% less DON than the yellow accessions in 2012 and they contained 46% less DON when the DON data were combined over 2 yr. In conclusion, black barley can be used as a means of mitigating DON contamination.

Legge, W. G., Tucker, J. R., Bizimungu, B., Tekauz, A., Fetch, Jr., T. G., Haber, S., Menzies, J. G., Noll, J. S., Turkington, T. K., Martin, R. A., Choo, T. M., Vigier, B. J., Blackwell, B. A. and Savard, M. E. 2013. Taylor barley. Can. J. Plant Sci. 93: 969–977. Taylor is a hulless two-row spring barley (Hordeum vulgare L.) cultivar with malting quality potential, and is one of the first hulless cultivars to be registered for that purpose in Canada. This line was developed in 2001 from a CDC Freedom/Rivers cross by in vitro selection using three Fusarium derived mycotoxins in the medium of an anther culture system. Taylor was evaluated in the Western Cooperative Hulless Barley Registration Test (2006–2008), and in pilot-scale malting trials (2007–2008), before being registered as HB705 in 2009 with its name changed to Taylor in 2011. In extensive evaluation in Fusarium head blight (Fusarium graminearum Schwabe) nurseries from 2002 to 2011, Taylor consistently showed low deoxynivalenol concentration.

Legge, W. G., Tucker, J. R., Bizimungu, B., Tekauz, A., Noll, J. S., Fetch Jr., T. G., Menzies, J. G., Haber, S., Savard, M. E., Vigier, B. J., Choo, T. M., Martin, R. A., Turkington, T. K., Rossnagel, B. G. and Harvey, B. L. 2011. Norman barley. Can. J. Plant Sci. 91: 1105–1113. Norman is a hulled two-row spring malting barley (Hordeum vulgare L.) cultivar derived from the cultivar CDC Kendall that was widely grown in western Canada and utilized commercially by the malting and brewing industry. Developed in 2000 by in vitro selection using deoxynivalenol mycotoxin in the medium of an anther culture system, Norman was evaluated in the Western Cooperative Two-row Barley Registration Test in 2005 and 2006, and the malting and brewing industry Collaborative Malting Barley Trials in 2006 and 2007, before being registered in 2009. Norman was also evaluated extensively for deoxynivalenol concentration in fusarium head blight (Fusarium graminearum Schwabe) nurseries from 2001 to 2009. Norman accumulates 25 to 30% less deoxynivalenol than its parent cultivar, CDC Kendall, but is similar in all other traits including malting quality.

A selection strategy based on agronomic traits was assessed to improve chemical composition of barley ( Hordeum vulgare L.). Two multi-environment datasets were investigated. They consisted of 190 doubled-haploid lines of the Léger/CI9831 cross and of 70 covered spike spring barley cultivars. Phenotypic correlations were assessed for four agronomic traits (test weight, seed weight, plant height and grain yield) and three chemical components [starch, acid detergent fibre (ADF), and total β -glucans]. A selection method is proposed on the basis of principal components analyses using genotype × trait (GT) biplots. Heavier test weight (>67 g hL −1 ) was a better predictor than kernel weight for the selection for lower ADF (<55 g kg −1 ) which is a desirable quality trait in feed barley. The negative correlation measured between test weight and ADF in both datasets has never been reported before in barley. Two-row barley genotypes suitable for improving the quality of feed barley were identified using the GT Biplot method.

TR05915 is an anther Culture derived doubled haploid two-row malting barley line selected from the cultivar CDC Kendall using in-vitro selection with deoxynivalenol (DON) added during the anther Culture step at Agriculture and Agri-Food Canada, Brandon, Manitoba, Canada. It was jointly developed with the Crop Development Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada, and will be registered for commercial production in 2009. TR05915 is similar to CDC Kendall in all traits, except that it accumulates about 25-30% less DON. Commercial acceptance of TR05915 should be facilitated since its malting quality is similar to CDC Kendall, a widely grown cultivar desired by maltsters and brewers.

The pathogenicity of eight Fusarium species causing fusarium head blight (FHB) in barley was studied under controlled conditions. Six barley genotypes varying in resistance to FHB were artificially inoculated with six isolates each of F acuminatum, F avenaceum, F crookwellense, F culmorum, F. equiseti, F. graminearum, F. poae and F. sporotrichioides 10-14 d after heading. Symptoms of FHB were rated as disease severity using a 0-9 scale, 4, 7, 14, 21 and 28 d after inoculation, and as percentage of infected spikelets (IS) after 21 d. All species tested caused head blight symptoms on the barley genotypes, but only F crookwellense, F culmorum and F graminearum resulted in severe disease development (> 65% IS) and were considered highly pathogenic. Fusarium avenaceum had 48% IS, which was significantly lower than those of the three highly pathogenic species and was moderately pathogenic. The remaining species had < 15% IS and were weakly pathogenic. There were significant differences (P < 0.05) in aggressiveness among isolates within species and in susceptibility among barley genotypes, suggesting that screening for resistance to FHB requires the use of aggressive isolates or a mixture of several isolates. This is the first report showing that F crookwellense is highly pathogenic and F avenaceum is moderately pathogenic on barley.

Many barley landraces are purple-or black-seeded, but the chemical composition of these purple-and black- seeded barley is rarely examined. Therefore, studies were conducted to determine if the chemical composition of purple and black barleys differs from that of yellow barleys. Four sets of genetic materials were used for these studies: 96 doubled-haploid (DH) lines, 10 near-isogenic lines, 40 landraces, and four F3 bulks. The results showed that purple DH lines contained a similar amount of lignin as yellow DH lines and that anthocyanin-containing isogenic lines did not differ from anthocyanin-free lines in lignin content. Therefore, these results suggest that anthocyanin biosynthesis is independent of lignin biosynthesis in barley. The results also showed that black barley contained more protein and more lignin than yellow barley in two crosses and that among the 40 landraces studied, the three with the highest concentration of lignin happened to be black seeded. Lignin content was not associated with seed weight except in defective endosperm lines. The presence of pigments and a relatively high concentration of lignin might help reduce the level of kernel blight severity in black barley. More studies are needed to determine the chemical composition and pest resistance associated with purple and black barleys.

The effect of time of harvest (at 75, 50,and 25% of milkline) on the incidence of kernel-borne Fusarium spp. was examined in four silage corn (Zea mays) hybrids (MAIZEX Leafy 4, NK BRAND Enerfeast 1, PIONEER 37M81 and MYCOGEN TMF94) in Ottawa, Ontario, in 2001 and 2002. Eleven Fusarium species were isolated over the 2 yr. Fusarium subglutinans was the dominant species recovered from 28.8% of the kernels. Other frequently isolated species included F oxysporum (2.6%), F graminearum (2.5%), F proliferatum (0.3%) and F sporotrichioides (0.2%). Trace amounts (< 0.1%) of the. remaining six species, F avenaceum, F crookwellense, F culmorum, F equiseti and F solani, were recovered from the kernels. When the kernels were harvested at 75, 50 and 25% of milkline, the incidence of F subglutinans increased from 20.9 to 26.7 and to 38.7%, respectively; that of F graminearum increased from 1.7 to 2.9 and to 3.1%; and for the total of the five main Fusarium species it increased from 28.7 to 32.2 and to 42.3%. Incidence of the other species was not affected by harvesting date. Of the four silage corn hybrids, NK BRAND Enerfeast1 had a significantly lower incidence of Fusarium species in kernels than the other hybrids, indicating a genotypic variation in resistance to kernel-borne infection by Fusarium species.

A portable narrowband spectroradiometer was used to detect sclerotinia stem rot infection, caused by the fungus Sclerotinia sclerotiorum in soybeans. Increasing levels of fungal inoculum were used to cause a gradient of disease infection in the field. Canopy reflectance measured in narrowband R/sub 675/-R/sub 685/ and broadband R/sub 635/-R/sub 685/ could estimate 86% of the variation in soybean p...

To investigate the effect of different environments on maize resistance to gibberella ear rot, disease symptoms, deoxynivalenol (DON) concentration, and grain yield were measured in three maize (Zea mays L.) inbred lines and five hybrids, from 1994 to 1996, at six locations in eastern Canada. At each location, all genotypes were inoculated with a three-isolate macroconidial mix of Fusarium graminearum Schwabe [teleomorph: Gibberella zeae (Schw.) Fetch] using a kernel-stab inoculation technique. Results show that year to year variation is more important than variation associated with multiple locations in testing for genotypic resistance to gibberella ear rot, according to disease symptoms and DON content. Severe ear rot and higher DON concentrations among genotypes prevailed in 1994, when environmental conditions during the growing season were more favourable for ear rot development. Regression models indicated that higher ear rot severity and DON concentration were associated with an increase in the total number of days from July to September with relative humidity equal to or greater than 80%. In a favourable environment, moderately severe ear rot symptoms gave up to a 48% yield reduction in susceptible maize hybrids.

Three types of commercial sweet corn hybrids [surgary (su1), shrunken or 'supersweet' (sh2) and surgary enhancer (se1)] were silk channel inoculated in 1996 and 1997 with a macroconidial suspension of Fusarium graminearum to determine how early the mycotoxin deoxynivalenol accumulates in kernels. Disease symptoms rapidly developed on all hybrids and were apparent 4 days after inoculation. Symptoms stabilized by 28 days after inoculation. Toxin levels were greater than 1 microgram/g in kernels as early as 2 weeks after silk emergence and rapidly increased to extremely high levels. Susceptibility in all hybrids decreased as the silk dried out. Deoxynivalenol concentrations were correlated to disease severity. There was some indication that the sh2 genotype was more susceptible than the su1 or se1 genotypes. These results suggest that improvement needs to be made in sweet corn with respect to resistance to gibberella ear rot.

The incidence of Fusarium species associated with maize ear rot in Ontario, the role of air temperature and rainfall, and the routes of fungal entry (silk, insects, and birds) were investigated. Samples and observations over 56 locations and 151 genotypes in southwestern and east-central Ontario during 1991-1993 showed that five Fusarium species (F. subglutinans, F. graminearum, F. moniliforme, F. proliferatum, and F. sporotrichiodes) were present on infected kernels. Fusarium subglutinans was the most frequently isolated species and its occurrence was negatively correlated with cumulative rainfall in July, while F. graminearum incidence increased with precipitation. Fusarium moniliforme and F. proliferatum occurred mostly following the hot, dry summer of 1991. Physical injury to the ear from insects and infection through the silk on the ear tip were the major routes of fungal entry. A regression model calculated to estimate ear rot incidence explained 70% of ear rot field observations based on F, subglutinans and F. graminearum incidence, route of fungal entry, and variation in July cumulative rainfall, while a simplified model version accurately predicted ear rot incidence on 31% of observations made on 15 genotype-locations over a 2-year period.