Hydrangea macrophylla is a highly valued ornamental shrub known for its captivating blooms and adaptability in various landscapes. Despite its popularity, the genetic resources available for hydrangeas are limited, posing significant challenges to advanced breeding efforts. High heterozygosity, large genome sizes, and a lack of comprehensive genomic data have complicated the identification of genetic variations tied to desirable traits. Addressing these challenges, this study paves the way for more precise and effective breeding strategies.
Conducted by researchers from the University of Florida, USDA-ARS, and Mississippi State University, the study (DOI: 10.1093/hr/uhad217) was published on November 9, 2023, in Horticulture Research. The team sequenced and analyzed the genomes of two hydrangea cultivars, ‘Veitchii’ and ‘Endless Summer’, revealing crucial genetic information related to flower shape, double-flower traits, and other key characteristics. This groundbreaking genomic resource provides new avenues for marker-assisted selection and lays the groundwork for future genetic research in hydrangea breeding.
The research marks the first assembly of high-quality reference genomes for hydrangea, highlighting genes that drive important flower traits. By comparing the genomes of ‘Veitchii’ and ‘Endless Summer’, researchers identified critical genes, including CYP78A5 (Cytochrome P450,CYP), linked to flower shape, and BAM3 (Barely Any Meristem, BAM), a novel gene associated with the double-flower phenotype. These discoveries illuminate the genetic divergence of hydrangea within the Asterid family and offer valuable insights for breeding more resilient, attractive cultivars. The newly developed genomic tools support precision breeding, enabling the targeted enhancement of traits like reblooming, cold hardiness, and disease resistance.
Dr. Amanda Hulse-Kemp, a lead researcher, remarked, "The assembly of these high-quality genomes is a transformative milestone for hydrangea research and breeding. It not only deepens our understanding of the plant’s evolution but also establishes a crucial foundation for developing new varieties with improved ornamental traits. This research moves us closer to precision breeding, allowing us to enhance specific flower characteristics in hydrangea."
The genomic resources developed in this study have far-reaching applications in ornamental horticulture and evolutionary biology. The identification of key genetic markers streamlines breeding programs, facilitating the rapid development of cultivars with unique flower shapes and enhanced resilience. Furthermore, these findings contribute to a deeper comprehension of Asterid evolution, supporting the conservation and utilization of genetic diversity within the group. The potential to harness these insights in breeding programs holds promise for boosting the market appeal and ecological impact of hydrangeas worldwide.
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References
DOI
10.1093/hr/uhad217
Original Source URL
https://doi.org/10.1093/hr/uhad217
Funding information
The research presented in this article was supported in part by funds from the Floral and Nursery Research Initiative administered through the United States Department of Agriculture, Agricultural Research Service (USDA-ARS). The work was supported by USDA-ARS CRIS project numbers 6066-21310-005-00D and 8020-21000-072-000-D.
About Horticulture Research
Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number two in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.