国立民族学博物館(みんぱく)は、博物館をもった文化人類学・民族学の研究所です。

東南アジアにおけるサトイモの遺伝的多様性のマッピングによる栽培化モデルの検証(2017-2020)

科学研究費助成事業による研究プロジェクト|基盤研究(B) 代表者 ピーター J. マシウス

研究プロジェクト一覧

目的・内容

To test old and new domestication models we will continue to map the distribution of wild populations of C. esculenta, record their morphological diversity, collect leaf tissue samples for DNA analysis, and then compare the wild populations with cultivatedC. esculenta and wild Colocasia species using DNA tests for past hybridization. This year our main target areas are India and Borneo.

活動内容

2019年度実施計画

To carry out fieldwork in India, a formal affiliation has been established with Delhi University. In May (2019) I will visit Delhi University, and then carry out fieldwork in the vicinity of Kolkata, to observe the utilisation of wild taro populations, andcollect taro leaf samples from the Ganges river delta region. In the second half of the year, I plan to visit Mt Kinabalu in Sarawak, Malaysia (Borneo Island) to observe wild populations of Colocasia oresbia and collect samples of wild C. oresbia and wildC. esculenta. Genetic analysis of samples previously collected in Vietnam (Mekong, Hue and Red River regions) and China (Guangxi, Guangdong, and Yunnan) will be continued. A manuscript for publication will also be prepared to report field surveys and genetic analyses from 2017 and 2018.

2018年度活動報告

In FY 2018, fieldwork was carried out in central Vietnam, and pilot studies were made in the delta of the Chao Praya River, near Bangkok, and innortheastern Bangladesh, in and around the Sylhet Basin. Working relationships were established with local researchers, and formal agreements forcooperation are now being prepared for collaboration with Kasetsart University, Bangkok, and Bangladesh Agricultural University, Mymensingh. Aformal affiliation with Dehli University has been established, and I am now attempting to obtain a research visa for visiting India in the nearfuture.In October, 2018, we carried out fieldwork in lowland and mountain areas around Hue city, central Vietnam. We collected samples from 43 sites,and discovered a previously undescribed species of wild taro in mountains near Hue and near the border between Hue and Laos. This appears to bethe same as a wild species seen in 2017 in Yunnan, and is an important discovery for understanding the evolutionary history of Colocasia species.New DNA sequence results were obtained for samples collected in 2017 in southern and northern Vietnam and southern China. The results confirmthat Colocasia sp. nova “spongifolia” (in Yunnan) is a distinct species, and that some lowland populations of wild taro include mixtures of twodifferent evolutionary lineages identified by chloroplast DNA analysis. By comparing chloroplast and nuclear DNA sequences at the same time, wehave found evidence for hybridisation between different evolutionary lineages of C. esculenta, and between different species of Colocasia.

2017年度活動報告

(a)サトイモの自生群におけるDNA配列変異の分析
台湾、フィリピン北部ですでに収集していたColocasia formosanaの標本についてDNAを抽出し葉緑体と核の遺伝子座のプライマーを使い配列を得た。これにより、 C. formosana と他のColocasia 種を識別することが可能になり、また、C. formosana内にかなり多様性があり、フィリピンのものは台湾で広範に見られる変異株と最も類似性があることがわかった。台湾とフィリピンの類似性と地理的隔離はこの共通して見られる変異株が年代的に古いもので長く安定していることを示す。アジア太平洋地域の栽培種についてこれまでに出版したデータと比較すると、栽培種は選択、栽培化、拡散を通じて厳密な遺伝子の隘路を通過したことを示している。

(b)野外調査と標本収集
ベトナムと中国南部のメコン川流域、紅河流域、珠江流域で野外調査を行い標本を収集した。形態学的特徴とColocasia種の同所性から、交雑種とみられる自生群がベトナム北部と中国南部で見つかった。また、自生する野菜として、豚の餌としてコメンサルワイルドなサトイモが利用されていることが確認できた。これらの標本についてはDNAの抽出を開始しており、葉緑体と核の遺伝子座のシーケンシングに取り掛かるところである。