Breeding for proanthocyanidin-free malting barley was initiated at Washington State University (WSU) in 1976, in collaboration with the Carlsberg Laboratory in Copenhagen. Considerable progress has been made in breeding this special brewing quality barley (Wettstein et al., 1985; Larsen et al., 1987; Cochran and Ullrich, 1988). Mutation breeding has been the foundation for providing new germplasm with sodium azide serving as the primary mutagen. In total 175 mutants have been induced and selected in North American spring barley sources.
Prior to 1987, new mutants were selected from field plantings of M2 populations by choosing the anthocyanin-free phenotype. Since anthocyanin and proanthocyanidin are produced in the same biochemical pathway (Wettstein et al., 1985), most visibly selected anthocyanin pigment-free mutants are proanthocyanidin-free as well. Since 1987 new mutants have been selected in the laboratory by non-destructively screening M3 seed with a vanillin-HCI solution and the Carlsberg Seed Fixation System (Aastrip, 1985; Kristensen and Aastrup, 1986). Table I contains a list of proanthocyanidin-free mutants selected at Washington State University using the Carlsberg Seed Fixation System. It is interesting to note that only eight of the 35 new mutants are anthocyanin-free indicating that a broader range of mutants are selected via M3 seed vs pigment-free M2 plants for the field. Small quantitites of seed are available to interested scientists.
Allele tests are in progress with these new mutants. Many of the previously selected WSU mutants (Ant 500-639) have been allele-tested at the Carlsberg Laboratory or WSU with results reported by Jende-Strid (1988).
Aastrip, S. 1985. A test for presence or absence of proanthocyanidins in barley and malt. Carlberg Res. Commun. 50:37-42.
Cochran, J. S., and S. E. Ullrich. 1988. Progress in breeding for proanthocyanidin-free barley. Barley Newsl. 31:89.
Kristensen, H., and S. Aastrup. 1986. A non-destructive screening method for proanthocyanidin-free barley mutants. Carlsberg Res. Commun. 51:509-513.
Jende-Strid, B. 1988. Coordinator's report: Anthocyanin genes. Stock list of ant mutants kept at the Carlsberg Laboratory. BGN 18:74-79.
Larsen, J., S. E. Ullrich, J. Ingversen, A. E. Nielsen, J. S. Cochran, and J. A. Clancy. 1987. Breeding and malting behavior of two different proanthocyanidin-free barley gene sources. In Barley Genetics V:767-772.
Wettstein, D. von, R. A. Nilan, B. Ahrenst-Larsen, K. Erdal, J. Inversen, B. Jende-Strid, K. Nyegaard, J. Larsen, H. Outtrup, and S. E. Ullrich. 1985. Proanthocyanidin-free barley for brewing: Progress in breeding for high yield and research tool in polyphenol chemistry. MBAA Tech. Quarterly 22:41-52.