Using molecular markers to determine barleys most suitable for malt whiskydistilling

Two barley quality characters of specific interest to whisky distillers are fermentability and production of the ethyl carbamate precursor, epi-hetero dendrin. The former is a quantitative trait, while the latter may be determ ined by a single Mendelian genetic factor. Molecular markers have been used to map, to barley chromosome 5(1H), the locus responsible for epi-heterode ndrin synthesis and the inheritance of this character and a closely linked microsatellite have been followed through the pedigrees of several contempo rary cultivars. Six loci, which affected fermentability in random inbred li nes from a barley cross, have been mapped to chromosomes 2(2H), 3(3H) and 7 (5H). This would permit the use of molecular markers in a breeding programm e, to select barleys best suited for distilling. In addition, one of the lo ci related to fermentability mapped to an area of the genome indicated, by a previous study, to affect the activity of beta-amylase, a character likel y to influence fermentability. Molecular markers may, therefore, be powerfu l tools in exploring the contribution and detecting the mode of action of t he genetical components influencing malt whisky distilling.