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A Nylon Fabric Technique for Studying the Ecology of Pythium aphanidermatum and Other Fungi in Soil. R. D. Lumsden, Research plant pathologist, Soilborne Diseases Laboratory, Plant Protection Institute, Agricultural Research, Science and Education Administration, U.S. Department of Agriculture, Beltsville, MD 20705; Phytopathology 71:282-285. Accepted for publication 30 August 1980. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1981. DOI: 10.1094/Phyto-71-282.

A nylon fabric was used to support and recover propagules of Pythium aphanidermatum after burial in clay loam and sandy loam soils. Oospores were trapped in the fabric mesh, buried in soil, incubated, retrieved, and examined microscopically. Destruction of the oospores was estimated from percentages that appeared to be disintegrating and their viability was determined by dislodging them from the fabric and plating them on a medium selective for Pythium. Fungistasis of soil to oospores could be assessed by burying nylon-mounted oospores in asparagine-amended soil and nonamended soil and comparing germination. Lysis of mycelia of P. aphanidermatum and production of sporangia from mycelia buried in soil were determined by assessing the number of mycelial strands and digitate sporangia present in unit areas of fabric. The nylon fabric also allowed convenient examination of fungal structures by scanning electron microscopy. Other structures examined by the nylon fabric method were zoospores of P. aphanidermatum; oospores of P. ultimum, P. myriotylum, and Aphanomyces euteiches; mycelia of Rhizoctonia solani; sclerotia of Sclerotinia minor; microconidia of Fusarium oxysporum; and microsclerotia and conidia of Verticillium dahliae.

Additional keywords: antagonism, soil ecology, microparasitism.