Population structure and genetic diversity of Fusarium graminearum sensu stricto, the main wheat pathogen producing Fusarium head blight in Argentina

NADIA YERKOVICH; FUMERO V.; CANTORO, RENATA; JUAN PALAZZINI; CHULZE, SOFÍA

EUROPEAN JOURNAL OF PLANT PATHOLOGY

SPRINGER

Año: 2019

0929-1873

Fusarium head blight (FHB) is a devastatingdisease of small grains cereal in Argentina. FHB ismainly associated with species within the Fusariumgraminearum species complex, potential trichotheceneproducers. The control strategy success will be determinedby the interaction among genetic variability ofthe pathogen, the host susceptibility and the environmentalfactors. The aim of this study was to evaluate thegenetic variability of F. graminearum ss populationsdefined as temporal and spatial populations. Symptomaticspikes were collected during an FHB outbreak(2012/13) and a non-outbreak (2014/15) wheat-harvestseason from wheat fields in Argentina. Strains weremorphological and molecular analysed, of which fourstrains were Fusarium meridionale and 71 were Fusariumgraminearum ss. The fungal populations assessedby ISSR molecular markers showed a genetic diversity(GD = 0.999?1.00) and migration rateNm = 5 and structurepopulation determined K = 2. Subpopulation 1 (K1)was established by 29 strains isolated from MarcosJuárez (MJ) and Pergamino (PER) during the 2012/13and 2014/15 harvest seasons and subpopulation 2 (K2)was established by 46 strains isolated from Corral deBustos (CBU) and Carlos Pellegrini (CPE) during the2012/13 and 2014/15 harvest seasons. High genotypicand genetic diversity together with great differentiationwithin subpopulations and high gene flow would indicatethat the strains isolated in Argentina are part of thesame, unique and widespread population, aswas alreadyshown in a previous study. Understanding fungal geneticstructure and continue monitoring of F. graminearumss populations through different harvest seasons willassist not only breeders but also the development ofimproved management control strategies.