Browse Articles

Article|02 Dec 2022|OPEN
Genome-wide association study of 23 flowering phenology traits and 4 floral agronomic traits in tree peony (Paeonia section Moutan DC.) reveals five genes known to regulate flowering time 
Yuying Li1 ,† , Lili Guo1 ,† , Zhanying Wang2 , Dehui Zhao1 , Dalong Guo3 , John E. Carlso4 , Weilun Yin5 and Xiaogai Hou,1 ,
1College of Agronomy/College of Tree Peony, Henan University of Science and Technology, Luoyang, Henan, 471023, China
2Luoyang Academy of Agricultural and Forestry Sciences, Luoyang, Henan, 471000, China
3College of Forestry, Henan University of Science and Technology, Luoyang, Henan, 471023, China
4Department of Ecosystem Science and Management, Pennsylvania State University, University Park, PA 16802, USA
5College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
*Corresponding author. E-mail:
Both authors contributed equally to the study.

Horticulture Research 10,
Article number: uhac263 (2023)
Views: 243

Received: 27 Jul 2022
Accepted: 21 Nov 2022
Published online: 02 Dec 2022


Tree peony is a unique traditional flower in China, with large, fragrant, and colorful flowers. However, a relatively short and concentrated flowering period limits the applications and production of tree peony. A genome-wide association study (GWAS) was conducted to accelerate molecular breeding for the improvement of flowering phenology traits and ornamental phenotypes in tree peony. A diverse panel of 451 tree peony accessions was phenotyped for 23 flowering phenology traits and 4 floral agronomic traits over 3 years. Genotyping by sequencing (GBS) was used to obtain a large number of genome-wide single-nucleotide polymorphisms (SNPs) (107 050) for the panel genotypes, and 1047 candidate genes were identified by association mapping. Eighty-two related genes were observed during at least 2 years for flowering, and seven SNPs repeatedly identified for multiple flowering phenology traits over multiple years were highly significantly associated with five genes known to regulate flowering time. We validated the temporal expression profiles of these candidate genes and highlighted their possible roles in the regulation of flower bud differentiation and flowering time in tree peony. This study shows that GWAS based on GBS can be used to identify the genetic determinants of complex traits in tree peony. The results expand our understanding of flowering time control in perennial woody plants. Identification of markers closely related to these flowering phenology traits can be used in tree peony breeding programs for important agronomic traits.