VIEW ARTICLE

Rust Uredospores Increase the Germination of Pycnidiospores of Darluca filum. D. P. Swendsrud, Department of Plant Pathology, University of Minnesota, St. Paul, Minnesota 55101; L. Calpouzos, Department of Plant Pathology, University of Minnesota, St. Paul, Minnesota 55101. Phytopathology 60:1445-1447. Accepted for publication 21 April 1970. DOI: 10.1094/Phyto-60-1445.

Uredospores of Puccinia recondita significantly enhanced the germination of Darluca filum pycnidiospores at temp ranging from 12 to 35 C. Darluca spores stored at 7 and 33% relative humidity remained viable longer and germinated better when uredospores were present. A concn of at least 78,000 uredospores/ml was required to promote germination of D. filum. Uredospores exerted their positive effect on D. filum on either nutrient or water agar media. Uredospores of P. recondita and Uromyces phaseoli enhanced germination of D. filum, whereas spores of nonrust fungi did not.