title: Population Structure of Peronospora effusa in the Southwestern United States.
abstract: Peronospora effusa is an obligate pathogen that causes downy mildew on spinach and is considered the most economically important disease of spinach. The objective of the current research was to assess genetic diversity of known historical races and isolates collected in 2014 from production fields in Yuma, Arizona and Salinas Valley, California. Candidate neutral single nucleotide polymorphisms (SNPs) were identified by comparing sequence data from reference isolates of known races of the pathogen collected in 2009 and 2010. Genotypes were assessed using targeted sequencing on genomic DNA extracted directly from infected plant tissue. Genotyping 26 historical and 167 contemporary samples at 46 SNP loci revealed 82 unique multi-locus genotypes. The unique genotypes clustered into five groups and the majority of isolates collected in 2014 were genetically closely related, regardless of source location. The historical samples, representing several races, showed greater genetic differentiation. Overall, the SNP data indicate much of the genotypic variation found within fields was produced during asexual development, whereas overall genetic diversity may be influenced by sexual recombination on broader geographical and temporal scales.
authors.affiliation: Department of Entomology & Plant Pathology, University of Tennessee, Knoxville, Tennessee, United States of America.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Lyon
authors.affiliation: Department of Plant Pathology, University of Arkansas, Fayetteville, Arkansas, United States of America.
authors.forename: James
authors.initials: J
authors.lastname: Correll
authors.affiliation: Department of Plant Pathology, University of Arkansas, Fayetteville, Arkansas, United States of America.
authors.forename: Chunda
authors.initials: C
authors.lastname: Feng
authors.affiliation: Department of Plant Pathology, University of Arkansas, Fayetteville, Arkansas, United States of America.
authors.forename: Burt
authors.initials: B
authors.lastname: Bluhm
authors.affiliation: Department of Entomology & Plant Pathology, University of Tennessee, Knoxville, Tennessee, United States of America.
authors.forename: Sandesh
authors.initials: S
authors.lastname: Shrestha
authors.affiliation: Department of Horticulture, University of Arkansas, Fayetteville, Arkansas, United States of America.
authors.forename: Ainong
authors.initials: A
authors.lastname: Shi
authors.affiliation: Department of Entomology & Plant Pathology, University of Tennessee, Knoxville, Tennessee, United States of America.
authors.forename: Kurt
authors.initials: K
authors.lastname: Lamour
mesh_terms: D005838:Genotype; D044742:Peronospora / Q000235:genetics / Q000502:physiology*; D025341:Principal Component Analysis; D011336:Probability; D015203:Reproducibility of Results; D015206:Southwestern United States
references.citation: Mycologia. 2006 May-Jun;98(3):514-7
references.pmid: 17040080
references.citation: Plant Dis. 2014 Jan;98(1):145-152
references.pmid: 30708621
references.citation: Mol Ecol Resour. 2010 May;10(3):564-7
references.pmid: 21565059
references.citation: J Microbiol. 2011 Dec;49(6):1039-43
references.pmid: 22203571
references.citation: J Appl Microbiol. 2014 Aug;117(2):472-84
references.pmid: 24823269
references.citation: Mycol Res. 2007 Apr;111(Pt 4):381-91
references.pmid: 17509849
references.citation: Plant Dis. 2007 Nov;91(11):1392-1396
references.pmid: 30780741
references.citation: Plant Dis. 2024 Mar 26;:PDIS06231225RE
references.pmid: 37840290
references.citation: Bioinformatics. 2012 Oct 1;28(19):2537-9
references.pmid: 22820204
references.citation: Bioinformatics. 2005 May 1;21(9):2128-9
references.pmid: 15705655
references.citation: PLoS One. 2013 Dec 12;8(12):e82691
references.pmid: 24349339
references.citation: Genetics. 2000 Jun;155(2):945-59
references.pmid: 10835412
references.citation: Mol Plant Microbe Interact. 2012 Oct;25(10):1350-60
references.pmid: 22712506
references.citation: Plant Dis. 2003 May;87(5):567-572
references.pmid: 30812960