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Inheritance of Isozymes in the Smut Pathogen Tilletia indica. M. R. Bonde, Research plant pathologists, U.S. Department of Agriculture, Agriculture Research Service, Foreign Disease-Weed Science Research Unit, Ft. Detrick, Building 1301, Frederick, MD 21701; G. L. Peterson(2), and M. H. Royer(3). (2)Biological laboratory technician, U.S. Department of Agriculture, Agriculture Research Service, Foreign Disease-Weed Science Research Unit, Ft. Detrick, Building 1301, Frederick, MD 21701; (3)Research plant pathologist, U.S. Department of Agriculture, Agriculture Research Service, Foreign Disease-Weed Science Research Unit, Ft. Detrick, Building 1301, Frederick, MD 21701. Phytopathology 78:1276-1279. Accepted for publication 5 April 1988. 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/Phyto-78-1276.

Nineteen basidiospore lines of Tilletia indica, the causal agent of Karnal bunt of wheat, were tested by means of starch gel electrophoresis for specific isozyme alleles present at each of four putative polymorphic loci. These loci coded for the enzymes glucosephosphate isomerase, glucose-6-phosphate dehydrogenase, mannitol dehydrogenase, and nucleoside phosphorylase. The glucosephosphate isomerase and glucose-6-phosphate dehydrogenase loci each had three alleles, whereas the other loci each had two alleles in the isolates used in this study. The expressed genotypes of the parent basidiospores were compared with those of five single-teliospore progeny for each of 15 specific crosses. Electrophoretic results demonstrated inheritance of isozyme alleles by teliospores from the monobasidiospore lines. Basidiospores arising from germinating teliospores did not inherit alleles at heterozygous loci in the teliospores with equal frequency. Furthermore, some basidiospores inherited both alleles, indicating that many of the basidiospores may receive two haploid nuclei from the promycelium, or that some basidiospores may be aneuploids. All four loci can be used for genetic markers of this important pathogen and 12 other polymorphic loci, not examined in this study, also may prove valuable.