title: Rice Varieties in Archaic East Asia: Reduction of Its Diversity from Past to Present Times.
abstract: The Asian cultivated rice, Oryza sativa, is one of the most important crops feeding more than a third of global population. In spite of the studies for several decades, the origin and domestication history of rice varietal groups, japonica and indica, have not been fully unveiled. Genetic information of ancient rice remains is essential for direct and exclusive insight into the domestication history of rice. We performed ancient DNA analysis of 950- to 2,800-year-old rice remains excavated from Japan and Korea. We found the presence of both japonica- and indica-type varieties in the Yayoi period and the middle ages of Japan and the middle part of Korea Peninsula 2,000 years ago. It is popularly considered that japonica has been exclusively cultivated in northern part of East Asia including Japan and Korea. Our result disclosed unexpectedly wide diversity of rice varieties in archaic East Asia. The present results from ancient rice DNA reveal an exclusive insight for the domestication history of rice which is not provided as far as contemporary rice.
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kumagai
authors.affiliation: Department of Teacher Training and School Education, Nara University of Education, Nara, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kanehara
authors.affiliation: Nara National Research Institute for Cultural Properties, Nara, Japan.
authors.forename: Shin'ya
authors.initials: S
authors.lastname: Shoda
authors.affiliation: Tawaramoto Board of Education, Nara, Japan.
authors.forename: Saburo
authors.initials: S
authors.lastname: Fujita
authors.affiliation: Department of Archaeology, Graduate School of Humanities and Sociology, The University of Tokyo, Tokyo, Japan.
authors.forename: Shizuo
authors.initials: S
authors.lastname: Onuki
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China sueda@bs.s.u-tokyo.ac.jp liwang@hznu.edu.cn.
authors.forename: Shintaroh
authors.initials: S
authors.lastname: Ueda
authors.affiliation: School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China sueda@bs.s.u-tokyo.ac.jp liwang@hznu.edu.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
mesh_terms: D001208:Asia; D018556:Crops, Agricultural / Q000235:genetics*; D000072441:DNA, Ancient / Q000032:analysis*; D019143:Evolution, Molecular; D005202:Asia, Eastern; D014644:Genetic Variation; D018745:Genome, Plant; D007564:Japan; D012275:Oryza / Q000235:genetics*; D010802:Phylogeny; D000069600:Plant Breeding; D013045:Species Specificity
chemical_list: D000072441:DNA, Ancient
keywords: ancient DNA; genetic diversity; rice