研究者業績

上原 浩一

ウエハラ コウイチ  (Koichi Uehara)

基本情報

所属
千葉大学 大学院国際学術研究院 教授
学位
農学博士
理学修士

J-GLOBAL ID
200901054750610090
researchmap会員ID
1000010294

論文

 14
  • Watanabe Yoichi, Ichiro Tamaki, Sang‐Hun Oh, Atsushi J. Nagano, Koichi Uehara, Nobuhiro Tomaru, Harue Abe
    American Journal of Botany 2023年4月19日  
  • Grégoire Noël, Arnaud Mestrez, Philippe Lejeune, Frédéric Francis, Junko Kawai, Masayuki Miwa, Koichi Uehara, Ayako Nagase
    Urban Forestry & Urban Greening 79 127794-127794 2023年1月  
  • Yoichi W, Takahashi M, Nagano AJ, Uehara K, Abe H
    Heredity 126(5) 859-868 2021年  査読有り
    Geographic and environmental isolations of islands and the mainland offer excellent opportunity to investigate colonization and survival dynamics of island populations. We inferred and compared evolutionary processes and the demographic history of Rhododendron tsusiophyllum, in the Izu Islands and the much larger island Honshu, treated here as the mainland, using thousands of nuclear SNPs obtained by ddRAD-seq from eight populations of R. tsusiophyllum and three populations of R. tschonoskii as an outgroup. Phylogenetic relationships and their habitats suggest that R. tsusiophyllum had evolved and migrated from cold north to warm south regions. We detected clear genetic divergence among populations in three regions of Honshu and the Izu Islands, suggesting restricted migration between them due to isolated habitats on mountains even in the mainland. The three regions have different changes in effective population size, especially, genetic diversity and population size of the Izu Islands are small compared to the others. Further, habitats of populations in the Izu Islands are warmer than those in Honshu, suggesting that they have undergone adaptive evolution. Our study provides evidences of montane rather than insular isolation on genetic divergence, survival of populations and significance of adaptive evolution for island populations with small population size and low genetic diversity, despite close proximity to mainland populations.
  • Yoichi W, Ono E, Tsunamoto Y, Matsuo A, Suyama Y, Uehara K
    Tree Genetics & Genomes 17(3) 2021年  査読有り最終著者
    Plants growing in similar climates with extensively overlapping distributions may exhibit similar phylogeographic patterns, due to similarities in range shifts during past climatic oscillations. We tested and exploited this expectation in a comparison of the evolutionary and demographic histories of two related and co-distributed species endemic to Japan-Rhododendron pentaphyllum and R. quinquefolium. Genetic variation in sequences of noncoding chloroplast DNA regions and hundreds of nuclear single nucleotide polymorphisms were used to investigate 191 individuals from 13 populations of R. pentaphyllum and 142 individuals from 10 populations of R. quinquefolium. We found that the two species were not each other's closest relative, and we found different times to the most recent common ancestor of extant populations based on both chloroplast DNA and nuclear SNPs. Rhododendron pentaphyllum exhibited higher genetic variation between populations than R. quinquefolium, while the two species had similar patterns of genetic divergence between regions with slightly different divergence times. These lines of evidence suggest that the similar ranges of the two species are the result of repeated range shifts since speciation during climatic oscillations.
  • 片倉慶子, 河上友宏, 渡辺洋一, 藤井英二郎, 上原浩一
    日本緑化工学会会誌 44(4) 606-612 2019年  査読有り最終著者責任著者

MISC

 31

書籍等出版物

 1

共同研究・競争的資金等の研究課題

 24