GENETIC-ANALYSIS OF THE ACCUMULATION OF COR14 PROTEINS IN WILD (HORDEUM-SPONTANEUM) AND CULTIVATED (HORDEUM-VULGARE) BARLEY

The cold-regulated (COR14) protein of 14 kDa is a polypeptide accumula ted under low-temperature conditions in the chloroplasts of barley lea ves. In H. vulgare the COR14 antibody cross-reacts with two proteins, with a slightly different relative molecular weight around the marker of 14.4 kDa, referred to as COR14a and COR14b (high and low relative m olecular weight, respectively). In a collection of H. spontaneum genot ypes a clear polymorphism was found for the corresponding COR proteins . While some accessions showed the same COR pattern as cultivated barl ey, in 38 out of 61 accessions examined the COR14 antibody cross-react ed with an additional cold-regulated protein with a relative molecular weight of about 24 kDa (COR24). The accumulation of COR24 was often a ssociated with the absence of COR14b; the relationship between the COR 14b/COR24 polymorphism and the adaptation of H. spontaneum to differen t environments is discussed. By studying COR14 accumulation in cultiva ted barley we have found that the threshold induction-temperature of C OR14a is associated with the loci controlling winter hardiness. This a ssociation was demonstrated by using either a set of 30 cultivars of d ifferent origin, or two sets of frost-tolerant and frost-sensitive F1 doubled-haploid lines derived from the cross Dicktoo (winter type) x M orex (spring type). These results suggest that the threshold induction -temperature of COR14a can be a potential biochemical marker for the i dentification of superior frost-resistant barley genotypes.