Extraction and genetic control of two new water-soluble proteins of mature barley seed.

This paper describes the genetic control of two new water-soluble proteins in barley. Water-soluble proteins (WSPs) of mature barley seed form part of the albumin/globulin class of seed proteins. They can be extracted from hand-milled grain with water, though some WSPs are more efficiently extracted with a solution of 10 mM dithiothreitol. Polymorphisms for WSPs were detected in isoelectric focusing gels incorporating various ampholine combinations. Two new controlling genes (Wsp4 and Wsp5) have been identified and located using wheat/barley chromosome addition lines and barley doubled haploids. Wsp4 is located on chromosome 2 (2H), and Wsp5 was found to be tightly linked to Wsp2 on the long arm of chromosome 7 (5HL). Segregation of a sixth gene (Wsp6) is also described, but this has not been mapped. The results are discussed with respect to other previously mapped Wsp loci.