Ben-David Roi, Parks Ryan, Dinoor Amos, Kosman Evsey, Wicker Thomas, Keller Beat, Cowger Christina
First author: Department of Vegetables and Field Crops, Institute of Plant Sciences, ARO-Volcani Center, Bet Dagan 5025000, Israel; second and seventh authors: United States Department of Agriculture-Agricultural Research Service, Department of Plant Pathology, North Carolina State University, Raleigh 27695; third author: The Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel; fourth author: Institute for Cereal Crops Improvement (ICCI), The George S. Wise Faculty for Life Sciences Tel Aviv University, Tel Aviv 69978, Israel; and fifth and sixth authors: Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland.
Phytopathology. 2016 Aug;106(8):861-70. doi: 10.1094/PHYTO-07-15-0177-R. Epub 2016 Jun 8.
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.
以色列及其周边地区是驯化小麦品种（普通小麦和硬粒小麦）及其同域生长的野生近缘种的多样性中心，其中包括野生二粒小麦。我们研究了其专性白粉病病原菌——小麦白粉菌专化型（Blumeria graminis f. sp. tritici）的专化型内部分化情况。从以色列四个地理区域的三种寄主物种中总共收集了61个小麦白粉菌专化型分离株。利用38个小麦品系（包括21个抗性基因鉴别系）上的毒力模式以及假定中性的分子标记（简单序列重复和单核苷酸多态性）对分离株的遗传相关性进行了表征。所有分离株对所测试的所有三种小麦物种的至少一些基因型都具有毒性。所有分析将小麦白粉菌专化型的分离株群体分为两个不同的组，即来自驯化寄主的分离株和来自野生二粒小麦的分离株。检测到单向迁移，从栽培小麦的小麦白粉菌专化型群体迁移到野生二粒小麦的小麦白粉菌专化型群体，迁移率为每代五到六个迁移个体。这种基因流动可能有助于解释不同的栽培和野生小麦白粉菌专化型群体之间的重叠现象。总体而言，小麦白粉菌专化型显著分化为野生二粒小麦群体和栽培小麦群体，尽管结果不支持存在一个单独的二粒小麦专化型。
