Albumin polymorphism and mapping of a dimeric a-amylase inhibitor in wheat

Abstract

Any new protein or DNA marker is potentially useful to add detail to already constructed genetic chromosome maps and may be valuable in breeding programs wherever polymorphism exists. Non-gluten proteins represent 15–20% of total wheat grain proteins. Isoelectric focusing of wheat (Triticum aestivum L. em Thell.) proteins on ultrathin gels showed high resolution and was found to be a useful tool in the differentiation of wheat varieties. Seventeen hexaploid wheat varieties were screened to investigate polymorphism of albumin proteins using isoelectric focusing. Polymorphism was observed for albumin polypeptides of pI 5.20, 5.85, 6.25, and 7.1, and 8.0. The polymorphic protein of pI 7.1 was mapped by analysing doubled haploid populations from the intervarietal crosses, Cranbrook x Halberd and Synthetic x Opata 85. This protein locus was designated as Iha-B1.2, and is located on the short arm of chromosome 3B.