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ARS Home » Pacific West Area » Davis, California » Nat'l Clonal Germplasm Rep - Tree Fruit & Nut Crops & Grapes » Research » Research Project #438256

Research Project: Germplasm Evaluation for Sweet Cherry Genetic Diversity and Disease Resistance

Location: Nat'l Clonal Germplasm Rep - Tree Fruit & Nut Crops & Grapes

Project Number: 2032-21000-026-002-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Jun 1, 2020
End Date: Sep 30, 2022

1. Identify NPGS accessions of sweet cherry and wild crop relatives that are phenotypically resistant or tolerant to infection from the devastating diseases of powdery mildew, bacterial canker, and Western X. 2. Obtain a comprehensive dataset of genomic-wide genotypic data for NPGS accessions of sweet cherry and wild crop relatives. 3. Use the genomic-wide genotypic data to: a. allocate accessions to their correct species status. b. identify accessions redundancies and misnomers. c. make new pedigree connections, especially among ancestor of U.S. breeding germplasm. d. characterize genetic diversity at an unprecedented resolution. e. determine trait locus genotypes for the major Mendelian trait loci and quantitative trait loci of breeding relevance for sweet cherry. 4. Ensure the new phenotypic and genotypic datasets are publicly available by entry into the GRIN-Global database.

1. Disease resistance phenotyping: Phenotypic evaluation will be conducted for susceptiblity to three diseases via leaf disk assays. Stem and leaf material will be collected from the sweet cherry collection (n=~100) of P. avium and some wild crop relative species, maintained as field trees at the NCGR in Davis, CA. The diseases are powdery mildew, bacterial canker, and Western X. 2. SNP array genotyping: a subsample of the leaf material from Activity 1 will be used to extract genomic DNA for the sweet cherry accessions and wild crop relatives in the NPGS collection that have not yet been dissected genetically via the 6+9K SNP array (n=48, where 48 is the minimum set of arrays that can be purchased at a time). The new data will be added to our already-obtained raw SNP array data dataset on the bulk of the NPGS cherry collection. 3. Genetic diversity analysis: The curated SNP array dataset of the entire NPGS sweet cherry crop (n=~100) will be characterized for: (a) species allocation, specifically P. avium vs. P. cerasus, interspecific hybridity, and close alignment with species other than the NPGS record for that accession: (b) redundancies and misnomers in the collection in the form of complete identity between two or more accessions as well as accessions with a unique name but the same DNA profile as a readily commercially available cultivar and not associated with a unique phenotype in its passport data. (c) U.S. sweet cherry cultivar pedigree, and (d) genetic diversity amoung accessions as determined by haplotype uniqueness at haploblocks.