Co-Authors:
Ben-David, R., Department of Vegetables and Field Crops, Institute of Plant Sciences, ARO-Volcani Center, Bet Dagan, Israel
Parks, R., United States Department of Agriculture, Agricultural Research Service, Department of Plant Pathology, North Carolina State University, Raleigh, United States
Dinoor, A., Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, Israel
Kosman, E., Institute for Cereal Crops Improvement (ICCI), George S. Wise Faculty for Life Sciences, Tel Aviv University, Tel Aviv, Israel
Wicker, T., Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, Zurich, Switzerland
Keller, B., Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, Zurich, Switzerland
Cowger, C., United States Department of Agriculture, Agricultural Research Service, Department of Plant Pathology, North Carolina State University, Raleigh, United States
Abstract:
Israel and its vicinity constitute a center of diversity of domesticated wheat species (Triticum aestivum and T. durum) and their sympatrically growing wild relatives, including wild emmer wheat (T. dicoccoides). We investigated differentiation within the forma specialis of their obligate powdery mildew pathogen, Blumeria graminis f. sp. tritici. A total of 61 B. graminis f. sp. tritici isolates were collected from the three host species in four geographic regions of Israel. Genetic relatedness of the isolates was characterized using both virulence patterns on 38 wheat lines (including 21 resistance gene differentials) and presumptively neutral molecular markers (simple-sequence repeats and single-nucleotide polymorphisms). All isolates were virulent on at least some genotypes of all three wheat species tested. All assays divided the B. graminis f. sp. tritici collection into two distinct groups, those from domesticated hosts and those from wild emmer wheat. One-way migration was detected from the domestic wheat B. graminis f. sp. tritici population to the wild emmer B. graminis f. sp. tritici population at a rate of five to six migrants per generation. This gene flow may help explain the overlap between the distinct domestic and wild B. graminis f. sp. tritici groups. Overall, B. graminis f. sp. tritici is significantly differentiated into wild-emmer and domesticated-wheat populations, although the results do not support the existence of a separate f. sp. dicocci. © 2016, American Phytopathological Society. All rights reserved.