SOMATIC RECOMBINATION IN USTILAGO HORDEI DURING THE PARASITIC PHASE ON BARLEY

Abstract

The method used in this study was designed to demonstrate the existence of somatic recombination in operation during the parasitic phase of the smut fungus Ustilago hordei (Pers.) Lagerh. Barley seeds were inoculated with mixtures of nutritionally deficient mutants of U. hordei. Inoculations were arranged in such a way that the parasitic phase would be completed only if an unusual event, such as somatic recombination, had taken place. Detailed analysis of putative somatic recombinant teliospores, obtained from an infected plant, was carried out. It was concluded that somatic recombination was probably responsible not only indirectly for the unexpected appearance of a niacin deficiency, but also directly for the free reassortment of marker genes originally present in separate parental cultures.