Open AccessMicrosatellite Markers fromPeronospora tabacina, the Cause of Blue Mold of Tobacco, Reveal Species Origin, Population Structure, and High Gene Flow
Author(s) -
Marcin Nowicki,
Denita Hadziabdic,
Robert N. Trigiano,
Fabian Runge,
Marco Thines,
Sarah L. Boggess,
Jean Beagle Ristaino,
Otmar Spring
Publication year - 2022
Publication title -
phytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.264
H-Index - 131
eISSN - 1943-7684
pISSN - 0031-949X
DOI - 10.1094/phyto-03-21-0092-r
Subject(s) - biology , microsatellite , gene flow , blue mold , population , botany , gene , genetics , genetic variation , allele , demography , sociology , postharvest , penicillium expansum
Peronospora tabacina is an obligate parasite that causes blue mold of tobacco. The pathogen reproduces primarily by sporangia, whereas the sexual oospores are rarely observed. A collection of 122 isolates of P. tabacina was genotyped using nine microsatellites to assess the population structure of individuals from subpopulations collected from central, southern, and western Europe; the Middle East; Central America; North America; and Australia. Genetic variations among the six subpopulations accounted for ∼8% of the total variation, including moderate levels of genetic differentiation, high gene flow among these subpopulations, and a positive correlation between geographic and genetic distance (r = 0.225; P < 0.001). Evidence of linkage disequilibrium (P < 0.001) showed that populations contained partially clonal subpopulations but that subpopulations from Australia and Mediterranean Europe did not. High genetic variation and population structure among samples could be explained by continuous gene flow across continents via infected transplant exchange and/or long-distance dispersal of sporangia via wind currents. This study analyzed the most numerous P. tabacina collection and allowed conclusions regarding the migration, mutation, and evolutionary history of this obligate biotrophic oomycete. The evidence pointed to the species origin in Australia and identified intracontinental and intercontinental migration patterns of this important pathogen. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .