VIEW ARTICLE

Effects of Separation of Spores from the Chain and of Culture Age on Germination of Chlamydospores of Thielaviopsis basicola. B. T. Hawthorne, Research Assistant, Department of Plant Pathology, University of California, Riverside 92502, Present address of the senior author: Plant Diseases Division, D.S.I.R., Auckland, New Zealand; Peter H. Tsao, Associate Professor, Department of Plant Pathology, University of California, Riverside 92502. Phytopathology 60:891-896. Accepted for publication 30 December 1969. DOI: 10.1094/Phyto-60-891.

Intact chains of chlamydospores of Thielaviopsis basicola were segregated from endoconidia and mycelial fragments by repeated centrifugation in 1% K₂HPO₄, and the individual chlamydospores of the chains separated from each other by chitinase. Washed, separated chlamydospores from 6- to 12-week-old cultures did not require exogenous nutrients for germination. They germinated either in deionized water (76-91% germination) or in the presence of nutrients (79-94% germination). Treatments which caused partial or complete separation of the chlamydospore chains increased the germinability of the chlamydospores in deionized water. Individual, young chlamydospores from 3- to 4-week-old cultures germinated less well than older spores in deionized water, but both spores germinated equally well in nutrients. The interacting effects of chain separation, age, and nutrients may reflect differences in the structure of the spore walls.