Dataset Information

Genetic diversity and population structure of Alternaria species from tomato and potato in North Carolina and Wisconsin.

ABSTRACT: Early blight (EB) caused by Alternaria linariae or Alternaria solani and leaf blight (LB) caused by A. alternata are economically important diseases of tomato and potato. Little is known about the genetic diversity and population structure of these pathogens in the United States. A total of 214 isolates of A. alternata (n = 61), A. linariae (n = 96), and A. solani (n = 57) were collected from tomato and potato in North Carolina and Wisconsin and grouped into populations based on geographic locations and tomato varieties. We exploited 220 single nucleotide polymorphisms derived from DNA sequences of 10 microsatellite loci to analyse the population genetic structure between species and between populations within species and infer the mode of reproduction. High genetic variation and genotypic diversity were observed in all the populations analysed. The null hypothesis of the clonality test based on the index of association [Formula: see text] was rejected, and equal frequencies of mating types under random mating were detected in some studied populations of Alternaria spp., suggesting that recombination can play an important role in the evolution of these pathogens. Most genetic differences were found between species, and the results showed three distinct genetic clusters corresponding to the three Alternaria spp. We found no evidence for clustering of geographic location populations or tomato variety populations. Analyses of molecular variance revealed high (> 85%) genetic variation within individuals in a population, confirming a lack of population subdivision within species. Alternaria linariae populations harboured more multilocus genotypes (MLGs) than A. alternata and A. solani populations and shared the same MLG between populations within a species, which was suggestive of gene flow and population expansion. Although both A. linariae and A. solani can cause EB on tomatoes and potatoes, these two species are genetically differentiated. Our results provide new insights into the evolution and structure of Alternaria spp. and can lead to new directions in optimizing management strategies to mitigate the impact of these pathogens on tomato and potato production in North Carolina and Wisconsin.

SUBMITTER: Adhikari TB

PROVIDER: S-EPMC8382843 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Alternaria is often one on the most abundant fungal genera recovered from a wide array of plant hosts and environmental substrates. Many species within the sub-generic Alternaria section Alternaria are common plant pathogens that cause pre-harvest losses due to reduced productivity and post-harvest losses due to spoilage and contamination with mycotoxins. As certain species of Alternaria may have distinct mycotoxin profiles, and very broad host ranges, understanding the distribution of species by geography and host is critical for disease prediction, toxicological risk assessment, and guiding regulatory decisions. In two previous reports, we performed phylogenomic analyses to identify highly informative molecular markers for Alternaria section Alternaria, and validated their diagnostic ability. Here, we perform molecular characterization of 558 section Alternaria strains, collected from 64 host genera in 12 countries, using two of these section-specific loci (ASA-10 and ASA-19) along with the RNA polymerase II second largest subunit (rpb2) gene. The majority of strains (57.4%) originated from various cereal crops in Canada, which formed the main focus of our study. Phylogenetic analyses were used to classify strains into section Alternaria species/lineages, demonstrating that the most common species on Canadian cereal crops are Alternaria alternata and A. arborescens. Further population genetic analyses were consistent with A. alternata being a widely distributed species with relatively low levels of geographic isolation (i.e., Canadian isolates did not form distinct clades when compared to other regions). Our expanded sampling of A. arborescens has greatly increased the known diversity of this group, with A. arborescens isolates forming at least three distinct phylogenetic lineages. Proportionally, A. arborescens is more prevalent in Eastern Canada than in Western Canada. Sequence analyses, putative hybrids, and mating-type distributions provided some evidence for recombination events, both within and between species. There was little evidence for associations between hosts and genetic haplotypes of A. alternata or A. arborescens.

Dataset Information

Genetic diversity and population structure of Alternaria species from tomato and potato in North Carolina and Wisconsin.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets