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Survival and Growth of the Mycoparasite Darluca filum. G. W. Rambo, Graduate student, Department of Botany, University of Maryland, College Park 20742; G. A. Bean, Assistant Professor, Department of Botany, University of Maryland, College Park 20742. Phytopathology 60:1436-1440. Accepted for publication 20 April 1970. DOI: 10.1094/Phyto-60-1436.

After 5 months at 5 C, conidia of Darluca filum stored within pycnidia were 100% viable. Conidia released from pycndia after wetting did not germinate unless the spore masses were diluted in distilled water. Conidia that remained in the spore masses became greatly enlarged, vacuolated, and did not germinate when placed in distilled water. The addition of bean rust spores to water agar increased the width and amount of branching of D. filum germ tubes; penetration of rust spores was not observed. Adding the solvent extracts from rust uredospores or intact or ground bean rust uredospores to a complete medium increased mycelia and pycnidia production. Colony diam was greatest on a medium containing 10:0.1 g/liter of glucose-ammonium sulfate, and mycelial production increased with glucose level. Pycnidial production occurred only on a medium containing 0.1 g/liter of ammonium sulfate, and max pycnidial production resulted from the addition of 10 g/liter glucose.