PHYSIOLOGICAL, BIOCHEMICAL AND GENETIC REGULATION OF CARBOHYDRATE METABOLISM IN CEREAL TISSUES
Location: Cereal Crops Research
Title: Beta-Amylase activity and thermostability in wild and cultivated barleys with different Bmy1 intron III alleles
Submitted to: North American Barley Research Workshop Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: August 17, 2008
Publication Date: October 26, 2008
Citation: Vinje, M.A., Duke, S.H., and Henson, C.A. 2008. ß-Amylase Activity and Thermostability in Wild and Cultivated Barleys with Different Bmy1 Intron III Alleles. In: North American Barley Researchers Workshop Proceedings, October 26-29, 2008, Madison, Wisconsin, p. 9.
The third intron of barley (Hordeum vulgare L.) beta-amylase 1 (Bmy1) is extremely polymorphic. Specific insertion/deletions (indels) in the third intron have been correlated with beta-amylase activity and thermostability and may have potential as a selective marker for cultivar development. The Bmy1 third intron of 40 barley accessions was sequenced and four alleles (Bmy1.a, Bmy1.b, Bmy1.c, and Bmy1.d) were identified based on indels of 126-bp, 38-bp, 11-bp, and 21-bp. beta-Amylase activity and thermostability were assayed in 22 North American cultivars important to the malting and brewing community and 12 wild barley accessions, which are a rich source of genetic diversity. The cultivars were found to have the Bmy1.a and Bmy1.b alleles with beta-amylase activity ranges of 946-1723 and 1443-2146 U/g flour, respectively and beta-amylase thermostability ranges of 4.1-36 and 22.5-26.3% residual activity, respectively. Fisher’s least significant difference (LSD) analysis revealed cultivars carrying the Bmy1.a and Bmy1.b alleles to have significantly different activities and cultivars carrying the Bmy1.a allele to have significantly different thermostabilities. The wild barleys were found to carry Bmy1.a, Bmy1.b, and Bmy1.c alleles with beta-amylase activity ranges of 668-1124, 908-1554, and 628-1629 U/g flour, respectively and beta-amylase thermostabilities of 26.6-33.3, 20.4-27.7, and 23.2-49.1% residual activity, respectively. LSD analysis revealed significant different activities in accessions carrying the Bmy1.a, Bmy1.b, and Bmy1.c and significant different thermostabilities in accessions carrying the Bmy1.b and Bmy1.c alleles. These data suggest that the use of the Bmy1 intron III alleles as a marker to predict and select for beta-amylase activity and/or thermostability is unreliable.