Food for thought: genetic, historical and ethnobotanical studies of taro Colocasia esculenta (L.) Schott in Africa

Thesis

The presence of exotic plants both in Africa and in Asia has long attracted the attention of scholars who have attempted to understand the human activities linked to them. Archaeological and ethnographic evidence for the reconstruction of these activities is often very limited, but indirect methods such as the study of DNA have become useful tools in building models of early human dispersal. Among the plants that were carried across the Indian Ocean, sometimes known as the “tropical food kit”, the staple crop taro (Colocasia esculenta (L.) Schott) has continued to be the subject of ongoing research. The use of this crop in antiquity is well documented by discoveries of ancient taro starch granules found on archaeological artefacts from sites in Southeast Asia and the Pacific islands, making it one of the oldest plants consumed by people. However, less is known about the use of taro in Africa and the Mediterranean region, where it is found both in the wild and under cultivation - often representing a staple crop in Sub-Saharan Africa. In this doctoral thesis, genetic analysis was performed on modern samples of taro collected from Africa and other regions of the Indian Ocean, using four molecular markers. Two main clusters have been identified, and within this main sub-division four populations of taro have been detected in Africa. By integrating the genetic results with historical and linguistic research, and extensive ethnobotanical fieldwork in Africa, two of these populations are proposed to represent early translocations, with modern distribution patterns suggesting diverse dispersal routes at different times. These results open up a new scenario in which the “tropical food kit” is finally unpacked, with important historical implications for each of the crops contained within it.

Authors: Grimaldi, IM

• Publication date: 2014
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: arum; ouingon; taro; Africa; Colocasia esculenta; Asian crop
• Subjects: Botanical sciences (see Plant sciences)