A Quantitative Method for Estimation of Teliospores of Tilletia indica in Soil. L. E. Datnoff, Research Affiliate, Foreign Disease-Weed Science Research Unit, USDA-ARS, Frederick, MD 21701. M. H. Royer, M. R. Bonde, and J. M. Prescott. Research Plant Pathologists, Foreign Disease-Weed Science Research Unit, USDA-ARS, Frederick, MD 21701, and Seed Health Pathologist, International Center for the Improvement of Maize and Wheat, Lisbon 27, Apdo. Postal 6-641, Mexico 06600 DF. Plant Dis. 72:209-212. Accepted for publication 8 September 1987. 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, 1988. DOI: 10.1094/PD-72-0209.

A bubbling-flotation-sieving method utilizing 50% glycerol was developed for the extraction of teliospores of Tilletia indica from artificially and naturally infested soil. A standard curve was prepared to estimate the number of teliospores recovered from soil artificially infested with about 50–5,000 teliospores per 10 g of soil. A log₁₀ transformation stabilized the variances of the number of teliospores recovered relative to the number actually present in soil. A prediction equation then was developed to estimate the number of teliospores in a naturally infested Mexican soil (X) based on the number of teliospores recovered (Y): log₁₀ X = (log₁₀ Y + 2)/1.47. The mean number of teliospores in Mexican soil was estimated to be between 476 and 1,617 per 10 g of soil. The sample sizes required for margins of error within 5, 10, 15, and 20% of the mean number of teliospores recovered also were determined. This methodology for the extraction and enumeration of teliospores of T. indica from Mexican clay soil will be useful in future studies on the ecology and epidemiology of the fungus.