title: Molecular and morphological data reveal hybrid origin of wild Prunus yedoensis (Rosaceae) from Jeju Island, Korea: implications for the origin of the flowering cherry.
abstract: OBJECTIVE
  The subgenus Cerasus of the genus Prunus includes several popular ornamental flowering cherries. Of the hundreds of cultivars, P. ×yedoensis ('Somei-yoshino') is the most popular and familiar cultivar in Korea and Japan and is considered to be of hybrid origin. However, the hybrid origin of P. ×yedoensis and its relationship to wild P. yedoensis, naturally occurring on Jeju Island, Korea, are highly controversial.
  
  
  METHODS
  We extensively sampled wild P. yedoensis, cultivated P. ×yedoensis, and numerous individuals from other species belonging to subgenus Cerasus on Jeju Island. Samples from 71 accessions, representing 13 species and one cultivar (P. ×yedoensis), were sequenced for nrDNA ITS/ETS (952 characters) and seven noncoding cpDNA regions (5421 characters) and subjected to maximum parsimony and maximum likelihood analysis. Additive polymorphisms in the ITS/ETS regions were confirmed by cloning amplicons from representative species.
  
  
  RESULTS
  The nuclear (ITS/ETS and G3pdh) and cpDNA data, along with several morphological characteristics, provide the first convincing evidence for the hybrid origin of wild P. yedoensis. The maternal parent was determined to be P. spachiana f. ascendens, while the paternal parent was unresolved from the taxonomically complex P. serrulata/P. sargentii clade. The presence of two kinds of ribotypes was confirmed by cloning, and the possible origin of cultivated P. ×yedoensis from wild populations on Jeju Island was also suggested.
  
  
  CONCLUSIONS
  Bidirectional and multiple hybridization events were responsible for the origin of wild P. yedoensis. Extensive gene flow was documented in this study, suggesting an important role of reticulate evolution in subgenus Cerasus.
authors.affiliation: Department of Biological Sciences, Sungkyunkwan University, 2066 Seobu-ro, Suwon 440-746, Korea.
authors.forename: Myong-Suk
authors.initials: MS
authors.lastname: Cho
authors.affiliation: Warm-Temperate and Subtropical Forest Research Center, Korea Forest Research Institute, Seogwipo, Jeju 967-050, Korea.
authors.forename: Chan-Soo
authors.initials: CS
authors.lastname: Kim
authors.affiliation: Department of Biological Sciences, Sungkyunkwan University, 2066 Seobu-ro, Suwon 440-746, Korea.
authors.forename: Seon-Hee
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Biological Sciences, Sungkyunkwan University, 2066 Seobu-ro, Suwon 440-746, Korea.
authors.forename: Ted Oh
authors.initials: TO
authors.lastname: Kim
authors.affiliation: Department of Biological Sciences, Sungkyunkwan University, 2066 Seobu-ro, Suwon 440-746, Korea.
authors.forename: Kyoung-In
authors.initials: KI
authors.lastname: Heo
authors.affiliation: National Institute of Biological Resources, Nanji-ro 42, Seo-gu, Incheon, 404-708, Korea.
authors.forename: Jumin
authors.initials: J
authors.lastname: Jun
authors.affiliation: Department of Biological Sciences, Sungkyunkwan University, 2066 Seobu-ro, Suwon 440-746, Korea.
authors.forename: Seung-Chul
authors.initials: SC
authors.lastname: Kim
mesh_terms: D035264:Flowers / Q000033:anatomy & histology / Q000235:genetics; D051456:Gene Flow; D006824:Hybridization, Genetic; D062312:Islands; D010802:Phylogeny; D011110:Polymorphism, Genetic; D027861:Prunus / Q000033:anatomy & histology / Q000235:genetics*; D056910:Republic of Korea
keywords: ITS; Jeju Island; Prunus yedoensis; Rosaceae; bidirectional hybridization; cpDNA noncoding regions; flowering cherry; hybrid origin