Genetic diversity of old French six-rowed winter barley varieties assessed with molecular, biochemical and morphological markers and its relation to BaMMV resistance

Twenty-six old French six-rowed winter barley (Hordeum vulgare L.) varieties were characterized for their reaction against barley mild mosaic virus (BaMMV). The genetic diversity of these varieties and two recent barley varieties was assessed using molecular, biochemical and morphological data. Seven old varieties were fully resistant to BaMMV. A higher differentiation level between varieties was observed by using DNA molecular markers compared to biochemical and morphological ones. Correspondence analysis using all markers showed that DNA molecular data could fully discriminate between ail varieties, whereas biochemical and morphological markers were not able to achieve a complete discrimination. The dendrogram clustering computed with the DNA marker dissimilarity index showed two main groups. The first group included the seven varieties resistant to the BaMMV, whereas the second contained susceptible varieties. The relationships between these varieties, their diversity level, and their characterization are discussed. We infer that the seven BaMMV-resistant varieties have a common origin.