No abstract

Fusarium head blight (FHB) is a widespread disease of cereals, including barley (Hordeum vulgare L.), that causes substantial grain yield losses and grain quality deterioration. Resistant varieties provide the greatest potential for reducing FHB. In the present study, we adapted two methods for screening FHB severity using Fusarium culmorum. We used a cut-spike method and a spray inoculation method in the field conditions for screening different spring barley genotypes of Latvian and foreign origin. Screening with the cut-spike method was done for 126 different genotypes in 2008 and in 2009 and for 180 genotypes in 2010. In the years 2011 and 2012, the field inoculation method was used to screen 207 and 164 genotypes, respectively; part of material was tested simultaneously by both methods. A significant effect of genotype was found for both cut-spike and field inoculation methods (p < 0.001); field inoculation method showed a greater proportion of genotype effect and a higher heritability. Using area under the disease progress curve (AUDPC) and score obtained at 26 days after inoculation were equally effective. Correlations between results obtained by both methods in different years were not significant, though, the data of the same year correlated significantly (r = 0.36-0.47, p < 0.05). Results suggest that differences between breeding material can be assessed by both methods; however, the information obtained was contradictory for a number of genotypes. Considering the results and the fact that field inoculation method can more likely provide results of equal value to those in natural conditions in respect to identification of resistant and susceptible genotypes, field inoculation method was recognized as preferable for the assessment of spring barley breeding material. Significant correlation (r = 0.71, p < 0.05) between visual estimate of disease severity and mycotoxin deoxynivalenol (DON) concentration in grain was found in 2011, but in the environmental conditions of 2012 formation of DON was inhibited.

The objectives of the investigation were to identify competitive traits in cereal species in order to contribute to development of a methodology for evaluation of cereal genotypes for their competitive capacity against weeds, which is important for organic breeding aims. The investigation was carried out with spring barley, spring oat, winter triticale and winter wheat genotypes in organic crop rotations in two different locations. Relations between crop traits and weed dry weight were evaluated by Pearson correlation coefficients. The results stressed the significance of some crop traits for cereal competitiveness against weeds for organic breeding purposes: (i) growth habit, canopy height, and crop development rate for spring barley; (ii) crop development rate for spring oats; (iii) winter hardiness and the coefficient of tillering for winter triticale, and (iv) winterhardiness, the coefficient of tillering, the number of productive stems, crop canopy and plant height for winter wheat. It coud be useful to include measurements of crop ground cover for estimating competitiveness of cereal species against weeds

Variation of spring barley agronomic traits significant for adaption to climate change in latvian breeding programmes Breeding programmes have been recently challenged by climate change. Spring barley (Hordeum vulgare L.) yield, phenological traits (days to heading, length of filling period and days to maturity) and resistance to powdery mildew and net blotch, which are influenced by the rising temperature and precipitation, along with threshability in hulless, were evaluated and their genetic and environmental variability were determined. One hundred and ninety spring barley genotypes were studied, including 129 hulless genotypes and 61 hulled genotypes. The genotypes were grown in the State Stende Cereal Breeding Institute and State Priekuļi Plant Breeding Institute for three seasons during 2007-2009. Broad-sense heritability estimated on the basis of genotypical and phenotypical variances for all traits of hulled barley varied from 31 to 98, and 42 to 98% for hulless barley. For both types of barley the highest heritability was observed for days to heading, filling period and days to maturity. Despite the relatively high estimated heritability for all traits, nevertheless, location, year and interaction of genotype and environment were also been significant for all traits.

Lunasin is a plant peptide that has health benefits such as cancer-preventing, antioxidant, anti-inflammatory, and cholesterol-lowering effects. However, there is actually no information on the influence of cropping on the lunasin content of cereals. Therefore, we studied lunasin in 22 spring barley genotypes grown both organically and conventionally during two seasons. We found that lunasin content of barley grain averaged 44.8 μg/g, ranging from 5.0 to 189.0 μg/g. Organic farming increased average lunasin content by 47-92 %. Ten out of 22 genotypes produced significantly more lunasin under organic farming in both years. Our findings evidence positive effects of organic farming on lunasin content in barley.