- 著者
- Leiko Mizusawa Naoko Ishikawa Okihito Yano Shinji Fujii Yuji Isagi
- 出版者
- The Japanese Society for Plant Systematics
- 雑誌
- Acta Phytotaxonomica et Geobotanica (ISSN:13467565)
- 巻号頁・発行日
- vol.70, no.2, pp.87-102, 2019-06-30 (Released:2019-07-10)
Clerodendrum trichotomum s. lat., under which many infraspecific taxa have been recognized, includes both tetraploid and diploid individuals, although chromosome numbers and geographic variation in ploidy levels have not been investigated in the Japanese archipelago. The geographic distribution of ploidy levels and chloroplast haplotypes of four Japanese taxa of C. trichotomum s. lat., based on chromosome counts, flow cytometry, and genotyping of five microsatellite loci is reported. It was determined that Japanese C. trichotomum var. trichotomum and var. yakusimense are tetraploid (2n = 104), while var. esculentum and C. izuinsulare are diploid (2n = 52). The diploid taxa are distributed only on the southern edge of the Japanese archipelago, while tetraploid C. trichotomum is distributed widely. Such distribution patterns may be formed by temperate forest shrinkage during, and tetraploid expansion after, glacial periods. Thirteen haplotypes were detected, and were divided into the following three clades: (1) Japanese C. trichotomum var. trichotomum and C. izuinsulare, (2) C. trichotomum var. yakusimense and var. esculentum, and (3) Chinese C. trichotomum. Two haplotypes were shared between diploid and tetraploid lineages, suggesting multiple polyploidization events in C. trichotomum s. lat.. Inconsistency between nuclear and chloroplast phylogenetic trees suggests a past inter-lineage hybridization event in C. trichotomum s. lat.
- 著者
- Kazutoshi Masuda Hiroaki Setoguchi Koki Nagasawa Shigeru Fukumoto Masae Iwamoto Ishihara Rei-ichi Miura Leiko Mizusawa Ken-ichi Hiratsuka Shota Sakaguchi
- 出版者
- The Genetics Society of Japan
- 雑誌
- Genes & Genetic Systems (ISSN:13417568)
- 巻号頁・発行日
- pp.21-00021, (Released:2021-06-18)
- 参考文献数
- 20
- 被引用文献数
- 2
Arnica mallotopus is a perennial herb endemic to the snowy regions of Japan. At the southern edge of its distribution, in Kyoto Prefecture, overgrazing by sika deer and decreased snowfall have resulted in the rapid decline of A. mallotopus populations. Therefore, there is an urgent need for a conservation genetic analysis of the remaining local populations. In this study, we first developed 13 EST-SSR markers to evaluate genetic variation in A. mallotopus. The average number of alleles per locus was 5.33. Genetic analysis using these markers showed that the investigated samples were classified into two groups corresponding to landscape structure. One group isolated from a tributary of the Yura River showed a strong population bottleneck signal, likely resulting from founder effects and subsequent drifts. On the other hand, the genetic diversity of the second group in the main distribution along the Yura River was higher and less inbred. Overall, our assessment suggested recognizing the two genetic groups as management units in conservation programs for the threatened populations.