| 研究実績の概要 |
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 in northeastern Bangladesh, in and around the Sylhet Basin. Working relationships were established with local researchers, and formal agreements for cooperation are now being prepared for collaboration with Kasetsart University, Bangkok, and Bangladesh Agricultural University, Mymensingh. A formal affiliation with Dehli University has been established, and I am now attempting to obtain a research visa for visiting India in the near future.
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 be the 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 confirm that Colocasia sp. nova “spongifolia” (in Yunnan) is a distinct species, and that some lowland populations of wild taro include mixtures of two different evolutionary lineages identified by chloroplast DNA analysis. By comparing chloroplast and nuclear DNA sequences at the same time, we have found evidence for hybridisation between different evolutionary lineages of C. esculenta, and between different species of Colocasia.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
As planned. The research is based on a hypothesis regarding the role of hybridisation in the process of domestication for taro. Our initial results indicate that hybridisation is widespread among Colocasia species and within C. esculenta. The results also indicate that we need to continue exploration of the diversity of wild taro species in lowland and mountain areas adjacent to major river systems. The discovery of what appears to be a new wild species of Colocasia, in central Vietnam and southern China was unexpected. More work needs to be carried out before this key result can be published. Following the original research plan, we have targeted similar landscapes over a wide area. This approach has been very fruitful in terms of generating both expected and unexpected results. In this sense, the work is going as planned. It is now time to begin preparing initial results for publication, while continuing to pursue the approach already established for this project.
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| 今後の研究の推進方策 |
In FY 2019 I will focus on analysis and writing, while continuing fieldwork and collaboration. I plan to visit India at the earliest opportunity to begin work with Delhi University, and carry out fieldwork in the lower Ganges River delta near Kolkata. At the same time, I wish to visit the Kolkata Herbarium to review past collections of Colocasia spp. in India. I am now discussing collaboration with the University of Malaysia in Sawarak, Borneo, to study Colocasia oresbia in the vicinity of Mt Kinabalu, and plan to compare this mountain species with recently collected examples of wild Colocasia species in Vietnam and China. After the conclusion of MoU agreements with Bangladesh Agricultural University and Kasetsart University, I will also visit Bangladesh and Thailand to obtain samples for further comparative study of wild taros across Southeast Asia.
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