Location: Fruit and Tree Nut ResearchTitle: Population structure and phylogeny of some United States peach cultivars
Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/14/2021
Publication Date: 11/11/2021
Citation: Chen, C., Okie, W.R. 2021. Population structure and phylogeny of some United States peach cultivars. Journal of the American Society for Horticultural Science. 147, 1, 1-6. https://doi.org/10.21273/JASHS05117-21.
Interpretive Summary: Knowledge of genetic relationships among materials used for breeding will help future breeding programs. The USDA Byron peach breeding program maintains a collection of scion cultivars and selections that have never been studied with molecular markers. This report summarizes the analytical results from DNA markers genotyping data and reveals their relationships, which can be used in future breeding.
Technical Abstract: Materials in a peach breeding collection at the USDA Byron program have never been characterized with any molecular marker. Genotyping of the materials with microsatellite markers will generate data and knowledge of their relationships. In this study, twenty reliable microsatellite markers were used to genotype 736 materials and the data was subjected to analysis using different programs to show the population structure, genetic diversity, and phylogenetic relationship. STRUCTURE simulations revealed four K clusters (K = 4) and genetic admixture among the materials. Alleles or genotypic composites in those US cultivars were largely derived from early heavily used ‘Chinese Cling’, European introductions and their offspring in breeding. Principal coordinate analysis (PCoA) and principal component analysis (PCA) of the 18 tentative groups showed these US cultivar groups were closely related to each other and intertwined in PCoA and PCA charts. Phylogenetic trees of the collection and US cultivars were also drawn using pairwise genetic distances. Within groups, the hybrids from Chinese wild species group had the highest pairwise distance means (0.65), whereas the Michigan cultivars group had the lowest (0.21), which corroborated with the results of STRUCTURE simulations. Most pairwise distance means with and between US cultivar groups were relatively low, suggesting close phylogenetic relations among those cultivars. Limiting factors and perspectives relevant to peach breeding are discussed.