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Techniques

Rapid Isolation of Sclerotia of Sclerotium cepivorum from Muck Soil by Sucrose Centrifugation. B. Vimard, Research assistant, Centre for Pest Management, Simon Fraser University, Burnaby, B.C., Canada V5A 1S6, Present address: Department of Plant Science, Macdonald Campus of McGill University, Ste. Anne de Bellevue, Quebec H9X 1C0; M. E. Leggett(2), and J. E. Rahe(3). (2)(3)Former graduate student, and professor, respectively, Centre for Pest Management, Simon Fraser University, Burnaby, B.C., Canada V5A 1S6, (2)Present address: Department of Soil Science and Plant Nutrition, University of Western Australia, Nedlands, W.A. 6009 Australia. Phytopathology 76:465-467. Accepted for publication 29 October 1985. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/Phyto-76-465.

A centrifugation procedure was developed to reduce the time needed to recover sclerotia of Sclerotium cepivorum from muck soil. Centrifugation of the soil fraction containing particles measuring 0.2-0.6 mm in diameter in 2.5 M sucrose speeded the density-dependent separation of sclerotia and reduced the number of soil particles retained with the sclerotia. Incubation of recovered sclerotia at 17 C selectively favored growth of S. cepivorum over contaminants and increased the sensitivity of the viability tests.