HORDEIN VARIATION IN WILD (HORDEUM SPONTANEUM) AND CULTIVATED (H.VULGARE) BARLEY

Abstract

The storage protein hordein contains two major groups of polypeptides which are highly polymorphic in barley, and in its evolutionary progenitor Hordeum spontaneum Koch. Crosses between the two species showed that the complex electrophoretic phenotypes within the two groups of polypeptides are governed by codominant alleles at two corresponding loci, Hor-1 and Hor-2, which are moderately linked (11% ± 2). In natural populations of the wild species, the two complex hordein loci were much more polymorphic than the allozyme loci. Furthermore, the variation at these two loci was highly correlated so that individuals differ from one another at both loci much more frequently than expected from the allele frequencies at the individual loci. Considerable hordein variation was also present in Composite Cross XXI, and there was evidence of reassortment of patterns by the seventeenth generation. Thus the complex hordein loci, with their extreme diversity and linkage disequilibrium, are ideal markers for monitoring evolutionary processes in both natural, or composite cross populations.

In vitro synthesis of barley storage proteins

“…This has been determined by genetic analysis using conventional crosses between varieties (Shewry ~~, 1978dj Doll andBrown, 1980;Jensen et al, 1980) and chromosome-doubled monoploids (Shewry !i ~t 1980b). The analysis of conventional crosses is complicated by the fact that the endosperm is triploid; when scorine for recombination between the fB' and 'C' patterns it is necessary to take into account that there are two gene doses from the maternal pattern and one from the paternal parent.…”

Morocco as a possible domestication center for barley: biochemical and agromorphological evidence

“…The A-hordeins are less variable both in the cultivated and in the wild species than the B-, C-and D-hordeins (Dolí and Brown 1979;Shewry et al 1979Shewry et al , 1983 and are, therefore, more suitable biochemical markers in phylogenetical studies. Wheat CM-proteins were among those used by Johnson and coworkers in their exiensive studies on the origin and evolution of Aegilops-Triticum species (Johnson 1972: Johnson and Hall 1965.…”

Genetics of CM-proteins (A-hordeins) in barley

“…Solari and Favret (1971) located a number of loci controlling hordein polypeptides in a segment of chromosome 5. More recent work (Oram et al 1975;Shewry et al 1978Shewry et al , 1980Netsvetaev 1978;Sozinov et al 1978;Dolí and Brown 1979;Jensen et al 1980) has led to the characterization of two complex loci, Horl and Hor2, which encode C and B-hordeins, respectively, and are located in the short arm of chromosome 5. Lawrence and Shepherd (1981), using wheat-barley addition and translocation lines, located the gene for D-hordein in the long arm of the same chromosome, a finding which has been fully confirmed with the characterization of the Hor3 locus by Shewry et al (1983).…”