Presence of a Sexual Population of Puccinia graminis f. sp. tritici in Georgia Provides a Hotspot for Genotypic and Phenotypic Diversity

• DOI: 10.1094/phyto-06-19-0186-r
• Publication Date: 2019-07-24T13:07:28Z
• Authors: Pablo D. Olivera; Zoya Sikharulidze; Rusudan Dumbadze; Les J. Szabo; Maria Newcomb; Ketino Natsarishvili; Matthew N. Rouse; Douglas G. Luster; Yue Jin
• Keywords: Stem rust; Puccinia

Wheat stem rust, caused by Puccinia graminis f. sp. tritici, is a re-emerging disease exemplified recent epidemics new virulent races. Understanding the sources and origins of genetic variations in pathogen populations globally can facilitate development better strategies management. We analyzed 68 wheat rust samples collected between 2013 2015 from Georgia where incidences are frequent alternate host, common barberry, present. A total 116 single-pustule isolates were derived evaluated on differential lines to determine virulence phenotypes 23 races identified, many which detected for first time. Unique combinations including, Sr22+Sr24 Sr13b+Sr35+Sr37 detected. These pose challenges breeding programs because these genes used resistance Ug99 race group. Sixty-one genotyped using custom single-nucleotide polymorphism chip 17 genotypes identified. The contained 11 multilocus compared with 2014 2015, five three genotypes, respectively. higher levels genotypic diversity observed strongly indicated that sexual recombination occurs Georgian P. tritici population, Caucasus region Eurasia may be an important source races.[Formula: see text] Copyright © 2019 Author(s). This open access article distributed under CC BY 4.0 International license.