Population genetics of Phytophthora infestans in Denmark reveals dominantly clonal populations and specific alleles linked to metalaxyl-M resistance

TY - JOUR

T1 - Population genetics of Phytophthora infestans in Denmark reveals dominantly clonal populations and specific alleles linked to metalaxyl-M resistance

AU - Montes, Melanie Sarah

AU - Nielsen, B. J.

AU - Schmidt, S. G.

AU - Bødker, L.

AU - Kjøller, Rasmus

AU - Rosendahl, Søren

PY - 2016/6/1

Y1 - 2016/6/1

N2 - Control of the potato late blight pathogen Phytophthora infestans relies heavily on chemicals. The fungicide metalaxyl-M (Mefenoxam) has played an important role in controlling the disease, but insensitivity to the fungicide in certain isolates is now of major concern. A genetic basis for resistance to metalaxyl suggests the possibility for linking resistance phenotypes to specific population genetic markers, but in order to do this, the population genetic structure and mode of reproduction in a population must first be well described. The dynamics of metalaxyl-M resistance in the Danish population of P. infestans was characterized over the course of the 2013 growing season, as was the population genetic structure, using simple sequence repeat (SSR) genotypes and single nucleotide polymorphism (SNP)-based mitochondrial haplotyping of over 80 isolates. Both mating types A1 and A2 were present in most fields, but tests for recombination showed that clonal reproduction dominates in Danish populations. Genotype was not linked to haplotype and no differentiation was observed at the haplotype level, but rather between fields. Resistance phenotypes were linked to specific SSR alleles, demonstrating the potential for a more precise SNP-based marker system for predicting resistance to metalaxyl-M.

AB - Control of the potato late blight pathogen Phytophthora infestans relies heavily on chemicals. The fungicide metalaxyl-M (Mefenoxam) has played an important role in controlling the disease, but insensitivity to the fungicide in certain isolates is now of major concern. A genetic basis for resistance to metalaxyl suggests the possibility for linking resistance phenotypes to specific population genetic markers, but in order to do this, the population genetic structure and mode of reproduction in a population must first be well described. The dynamics of metalaxyl-M resistance in the Danish population of P. infestans was characterized over the course of the 2013 growing season, as was the population genetic structure, using simple sequence repeat (SSR) genotypes and single nucleotide polymorphism (SNP)-based mitochondrial haplotyping of over 80 isolates. Both mating types A1 and A2 were present in most fields, but tests for recombination showed that clonal reproduction dominates in Danish populations. Genotype was not linked to haplotype and no differentiation was observed at the haplotype level, but rather between fields. Resistance phenotypes were linked to specific SSR alleles, demonstrating the potential for a more precise SNP-based marker system for predicting resistance to metalaxyl-M.

KW - Phytophthora infestans

KW - Linkage disequilibrium

KW - Metalaxyl resistance

KW - Mitochondrial haplotypes

KW - Potato late blight

KW - Simple sequence repeat

U2 - 10.1111/ppa.12462

DO - 10.1111/ppa.12462

M3 - Journal article

AN - SCOPUS:84951019723

SN - 0032-0862

VL - 65

SP - 744

EP - 753

JO - Plant Pathology

JF - Plant Pathology

IS - 5

ER -