Henry, R.J., Johnston, R.P. 1991. Influence of genotype and environmental interaction on maltingquality. In: Munck, L. (ed.), Barley Genetics VI. Proc.: Sixth International barley genetics Symposium. July, 22–27, 1991. Helsingborg, Sweden, pp. 478
modification determination. Symposium on the Relationship between Malt and Beer, Helsinki, pp. 224–234.
Ellis, R.P., Camm, J.-P., Morrison, W.R. 1992. A rapid test for maltingquality in barley. HGCA Project report No. 63
β-Glucan content and β-glucanase activity of winter and spring barley cultivars grown under different environments were evaluated. There were significant differences in both β-glucan content and β-glucanase activity between analysed barleys. The results showed that, for all cultivars and locations, approximately 75% of β-glucan present in grains was degraded after malting, and that marked differences existed among winter and spring type of cultivars in malt β-glucan content. The correlation analysis of β-glucan content and malt quality parameters showed that malt β-glucan content was significantly positively correlated with viscosity and extract difference, and negatively with malt β-glucanase activity and friability. Regarding malt β-glucanase activity, significantly higher activity was found in spring cultivars in contrast to winter cultivars.
As one of the world’s earliest domesticated crops, barley is a model species for the study of evolution and domestication. Domestication is an evolutionary process whereby a population adapts, through selection; to new environments created by human cultivation. We describe the genome-scanning of molecular diversity to assess the evolution of barley in the Tibetan Plateau. We used 667 Diversity Arrays Technology (DArT) markers to genotype 185 barley landraces and wild barley accessions from the Tibetan Plateau. Genetic diversity in wild barley was greater than in landraces at both genome and chromosome levels, except for chromosome 3H. Landraces and wild barley accessions were clearly differentiated genetically, but a limited degree of introgression was still evident. Significant differences in diversity between barley subspecies at the chromosome level were observed for genes known to be related to physiological and phenotypical traits, disease resistance, abiotic stress tolerance, malting quality and agronomic traits. Selection on the genome of six-rowed naked barley has shown clear multiple targets related to both its specific end-use and the extreme environment in Tibet. Our data provide a platform to identify the genes and genetic mechanisms that underlie phenotypic changes, and provide lists of candidate domestication genes for modified breeding strategies.
Treatment of barley grain with gibberellic acid (GA3) during malting promotes abnormal proteolysis and rapid rootlets growth affecting malt quality. This study investigated the potential of ethylene treatment as an alternative by comparing the amylase activity, total starch and total reducing sugars of germinating ‘Puma’ barley seeds treated with ethylene, 1-methylcyclopropane (1-MCP), GA3, daminozide (B-nine), GA3 + 1-MCP, ethylene + B-nine and the control after 24, 48 and 72 h from soaking. Ethylene had no effect on amylase activity. B-nine reduced amylase activity by 16 and 9.6% compared to the control after 48 and 72 h, respectively. The amylase activity of ethylene + B-nine treated seeds was higher (13.3 and 4%) than B-nine treated seeds after 48 and 72 h. This suggest that endogenous GA is important for normal amylase activity and, ethylene stimulates amylase activity where GA synthesis is inhibited. Ethylene and GA3 treatments reduced starch (83.3 mg g−1 and 76.7 mg g−1, respectively) and increased reducing sugars (16.0 and 17.1 µg ml−1, respectively) compared to the control (115.3 mg g−1 starch and 12.1 µg ml−1 reducing sugars) after 72 h. It was concluded that, ethylene may replace GA3 treatment without interfering with starch changing processes during barley malting.