Suchergebnisse

Abstract
This study aimed to evaluate the performance and stability of agronomic and grain quality traits of 11 spring barley varieties from the Latvian breeding programme grown in two locations for four years. The study was carried out on 11 Latvian spring barley varieties: nine covered varieties 'Abava', 'Ansis', 'Austris', 'Didzis', 'Gāte', 'Idumeja', 'Jumara', 'Kristaps', and 'Saule PR' and two hull-less varieties 'Irbe' and 'Kornelija'. Plants of the varieties were grown in field trials of the Institute of Agricultural Resources and Economics, at two sites (Priekuïi and Stende) during 2014–2017. Varieties 'Didzis', 'Jumara', and 'Ansis' yielded significantly above the grand mean in eight environments (5.70 t·ha−1; LSD = 0.476 t·ha−1). 'Didzis' showed relatively high dynamic yield stability and broad adaptability to all environments (bi = 0.90; b = 1; s2
d = 0.07). Grain yield for varieties 'Jumara' and 'Ansis' showed specific adaptability to unfavourable environments (bi = 0.48 and 0.55, respectively; bi < 1). Some covered spring barley varieties were considered to be the best in eight environments with stable and high 1000 grain weight ('Austris', 'Idumeja'), test weight ('Gāte', 'Jumara', 'Austris'), lodging resistance ('Austris', 'Jumara', 'Didzis'), resistance to Pyrenophora teres ('Didzis', 'Saule PR') and Blumeria graminis ('Saule PR', 'Didzis'). Both hull-less barley varieties 'Irbe' and 'Kornelija' were distinguished for high crude protein and ß-glucan content.

Abstract
Differences in biochemical composition in dehulled and pearled grain samples affected by the various degrees of pearling were studied for spring barley (Hordeum vulgare L.). Twelve covered spring barley and two hulless genotypes were examined. Commercial samples of pearled barley were included for comparison. Covered barley grain samples were pearled using a small-scale barley pearler to obtain dehulled and pearled barley grain products with pearling percentage of 12% and 30%, respectively. Significant differences were observed in the chemical composition between dehulled grain and pearled grain. As the outer layers of the covered grain were removed to a greater degree by pearling, crude protein content, crude ash, total phenolic concentration and radical scavenging activity in the pearled grain significantly decreased (p < 0.001), while starch concentration increased, without changes in the β-glucans concentration. The concentration of phenolic compounds in the dehulled barley grain samples were 1.30 to 1.61 times higher than for pearled grains. There was a significant (p < 0.01) correlation determined among values of dehulled and pearled grain of different barley genotypes in crude protein, starch, and β-glucan content, but no relationship was found in total phenolic content and radical scavenging activity.

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.