Development of basidia and basidiospores in Uromyces species on wild barley and liliaceae in Israel

Abstract

Development of basidia and basidiospores varies in Uromyces rusts which have uredinia and telia on wild species of Hordeum and alternate with Liliaceous species. The same is true of short-cycled Uromyces species living on several members of the Liliaceae. Conventional rust types were observed in the two heteroecious species Uromyces hordeastri f.sp. bulbosi-autumnalidis , and U. reichertii , as well as in the microcyclic U. rayssiae which is correlated with U. reichertii . Simplified basidia have two binucleate cells and a basal cell lacking nuclei. Such basidia yield two binucleate basidiospores and are characteristic of U. christensenii . Several other heteroecious rusts, and the investigated formae speciales of the microcyclic U. scillarum have a similar basidial development. Basidia consisting of a binucleate cell with binucleate basidiospores, and uninucleate cells with uninucleate basidiospores were seldom found and were confined to heteroecious species. In U. viennotbourginii and U. christensenii inoculation with a single basidiospore induced development of aecia, while in U. scillarum f.sp. leopoldiae-maritimae inoculation with one basidiospore resulted in the formation of telia. These rust fungi are therefore self-fertile.