Mycelial Types and Pathogenicity of Puccinia recondita f. sp. tritici Grown on Artificial Media

Abstract

Vegetative growth of Puccinia recondita f. sp. tritici race 45 was obtained by placing aseptic wheat leaves bearing uredinia on media. Vegetative mycelium emerged from periphery of the uredinium or through the central slit from the mycelial mass formed in the respiratory cavity of stomata of the wheat leaves, not from the germtubes of urediniospores. Two kinds of colony types were observed: One which cease the vegetative growth within 2 months of incubation, and another which can be subcultured continuously. The former consists of masses of bold mycelia and is able to produce spores. The latter consists of narrow hyphae and does not produce spores. When epidermis-stripped aseptic wheat segments were placed on colonies, a uredinium was produced on the side of the leaf segment opposite to the colony 1 month after the inoculation.