Visualization of barley beta-glucan degrading isozymes after gel isoelectric focusing.

A simple method to study the polymorphism of barley (Hordeum vulgare L.) beta-(1-3,1-4)-glucanases (specific enzymes of barley beta-glucan hydrolysis) is described. Proteins of a crude extract of germinated barley kernels were separated in an immobilized pH gradient in two pH ranges (pH 3-10.5 and pH 4-7). beta-glucanases were visualized by contact printing with a polyacrylamide gel containing beta-glucan or lichenan. Patterns of beta-glucanases were revealed by staining with Congo Red with resultant clear zones on a stained background. Various conditions of germination, extraction and visualization were investigated. New isozyme bands could be detected and their nature and origin discussed.

Mapping of ß-glucan content and ß-glucanase activity loci in barley grain and malt.

Genetic study of ß-glucan content and ß-glucanase activity has been facilitated by recent developments in quantitative trait loci (QTL) analysis. QTL for barley and malt ß-glucan content and for green and finished malt ß-glucanase activity were mapped using a 123-point molecular marker linkage map from the cross of Steptoe/Morex. Three QTL for barley ß-glucan, 6 QTL for malt ß-glucan, 3 QTL for ß-glucanase in green malt and 5 QTL for ß-glucanase in finished malt were detected by interval mapping procedures. The QTL with the largest effects on barley ß-glucan, malt ßglucan, green malt ß-glucanase and finished malt ßglucanase were identified on chromosomes 2,1,4 and 7, respectively. A genome map-based approach allows for dissection of relationships among barley and malt ßglucan content, green and finished malt ß-glucanase activity, and other malting quality parameters.