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ARS Home » Northeast Area » Washington, D.C. » National Arboretum » Floral and Nursery Plants Research » Research » Publications at this Location » Publication #362387
Research Project: Genetic Improvement of Nursery Crops through Functional Genomics and Breeding

Location: Floral and Nursery Plants Research

Title: Genetic diversity and population structure analysis of Hydrangea macrophylla using genotyping-by-sequencing (GBS)

Author
item WU, XINGBO - Orise Fellow
item Alexander, Lisa

Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/21/2019
Publication Date: 8/1/2019
Citation: Wu, X., Alexander, L.W. 2019. Genetic diversity and population structure analysis of Hydrangea macrophylla using genotyping-by-sequencing (GBS). Journal of the American Society for Horticultural Science. 144(4):257-263.

Interpretive Summary: Hydrangea macrophylla is one of the most important floral and nursery crops worldwide. However, breeding of new hydrangea varieties has been hampered by its long breeding cycle and lack of genetic resources. In order to develop molecular resources for hydrangea and accurately characterize hydrangea germplasm, we used genotyping-by-sequencing (GBS) to develop single nucleotide polymorphism (SNP) markers and to categorize hydrangea cultivars into breeding groups. Diversity studies confirmed the taxonomic classification of H. macophylla ssp. serrata as a subspecies of H. macrophylla rather than a separate species. Population structure revealed a second gene pool within H. macrophylla ssp. macrophylla group caused by historical and modern breeding efforts. The SNP markers we discovered and the phylogenetic results facilitate further exploitation and understanding of relationships in hydrangea that will serve as a reference for hydrangea breeding.

Technical Abstract: Hydrangea macrophylla is one of the most important floral and nursery crops worldwide. However, breeding of new hydrangea varieties has been hampered by its long breeding cycle and lack of genetic resources. This study investigated genetic diversity and population structure of 83 hydrangea cultivars using single nucleotide polymorphisms originated from genotyping by sequencing (GBS). A total of 5,805 high quality SNPs were discovered in the hydrangea cultivar panel. Phylogenetic analysis and AMOVA based on discovered SNPs concluded the taxonomic classification of H. macrophylla ssp. serrata as a subspecies of H. macrophylla. Principal Component Analysis (PCA) confirmed ‘Preziosa’ to be a hybrid between H. macrophylla ssp. macrophylla and H. macrophylla ssp. serrata. In addition, another cultivar ‘Lady in Red’ was also found to be a hybrid between the two subspecies. Population structure analysis identified three groups among the 83 cultivars. All H. macrophylla ssp. serrata cultivars belonged to one group while and two groups were revealed within H. macrophylla ssp. macrophylla. The separation within H. macrophylla ssp. macrophylla indicated a second gene pool due to breeding efforts that have targeted similar breeding goals in hydrangea. The discovered SNPs and the phylogenetic results facilitate further exploitation and understanding of phylogenetic relationships in hydrangea that may serve as a reference for hydrangea breeding.