Restriction fragment analysis of ribosomal and hordein genes in eastern Canadian two-rowed barleys

Abstract

Restriction fragment length polymorphisms (RFLPs) have been advocated as useful genetic markers for a variety of genetic and plant breeding applications. Among barley cultivars, RFLPs have been reported in three well-characterized multigene families: at the hordein seed storage protein loci, at the 18S + 5.8S + 26S ribosomal DNA loci, and for 5S ribosomal DNA. The present study sampled RFLPs in these three gene families in the five major eastern Canadian two-rowed barley cultivars. The target sequences constitute at least six loci distributed over at least three chromosomes but represent a very small percentage of the total genome. The five cultivars studied share common alleles at the 18S + 5.8S + 26S ribosomal loci Rrn 1 and Rrn 2 and at the 5S ribosomal loci. This may reflect a fairly narrow genetic base for these cultivars. Moderate amounts of polymorphism were detected at the Hor 1 and Hor 2 loci, each of which comprises a small multigene family. Restriction fragment length polymorphism complemented protein polymorphism at the hordein loci, arguing for their joint use for cultivar identification or similar purposes.Key words: barley, restriction fragment analysis, restriction fragment length, polymorphisms, hordeins, ribosomal DNA.