Yams of West and South West Ethiopia
Conserving yam agrobiodiversity and associated indigenous knowledge for Ethiopia’s future.
Yam diversity in Ethiopia and its value
Yams (Dioscorea), like the banana relative enset (Ensete), are long-established and important food crops for many communities in South West and West Ethiopia, but their future is under threat. The threats yams face include the spread of cereal cultivation, cash cropping (especially for coffee), cultural and climate change. This area is part of the Southern Nations, Nationalities, and People's Region (SNNPR) of Ethiopia. Wolaita and Gamo Gofa Zones and Basketo Special Woreda in particular are home to significant diversity in both agricultural and wild plants, forming the basis for the use and desirability of yams in the region. Native yams and enset, along with introduced sweet potatoes and taro, provide a reliable source of food in much of the SNNPR, a densely populated area with over 15 million inhabitants, especially in areas between about 1,400 and 2,000 m in altitude. This is due to their adaptation to the region’s seasonal climate and environmental conditions. It is also home to a yam crop wild relative species Dioscorea abyssinica.
Conservation of diversity and associated biocultural knowledge
Yams, like enset, are closely interwoven with indigenous cultural life in the SNNPR. However, current patterns of social and agricultural development coupled with deforestation threaten to erode the knowledge that underpins yam cultivation, yam genetic diversity and the complex genetic interaction with wild forest yam plants that helps to generate and maintain diversity through ennoblement. Ennoblement is where wild or land race yams are taken from forest to cultivated areas and subsequently acquire desirable crop plant characteristics in cultivation. This provides genetic enrichment of cultivated yam populations. Both the wild and cultivated yam diversity and the associated cultural knowledge need to be preserved for use by future generations to retain agro-ecosystems that successfully feed communities and are likely to be resilient in the face of suboptimal conditions caused by climate change. It is already apparent that biocultural knowledge is not being transferred to younger generations sufficiently to maintain yam-based agriculture. These threats may in the future reach a critical threshold beyond which loss of traditional knowledge and diversity will be irreversible.
Global role of Ethiopian yam agrobiodiversity collections
Yam diversity from South West and West Ethiopia has the potential to play an important part in the search for traits such as resistance to the main viral and fungal pathogens of yams worldwide but has yet to be utilised by breeders.
Role of RBG Kew
Coordination and co-management of the project and technical assistance in databasing and website establishment.
- Capture and dissemination of information on yam diversity in Ethiopia and the associated cultural knowledge to prevent its loss.
- Carry out field-based inventory of yam cultivation in SW Ethiopia and investigation into ennoblement.
- In situ yam conservation.
- Create reference living collections of Ethiopian yam diversity.
- Create reference collection of herbarium material.
- Project website with SNNPRS farmers’ variety pages.
- Hard copy guide to SNNPRS yam diversity in Amharic.
- Two living agrobiodiversity collections covering all the farmers’ varieties of yam from Wolaita and Gamo Gofa Zones and Basketo Special Woreda linked to databased field information.
- Reference collection of herbarium specimens at Addis Ababa University.
- Community yam workshops and gardens.
- Addis Ababa University, Ethiopia
- Arba Minch University, Ethiopia
- Hawassa University, Ethiopia
Abebe, W., Demissew, S., Fay, M.F., Smith, R.J., Nordal, I. & Wilkin, P. (2012)
Genetic diversity and population structure of guinea yams and their wild relatives in South and South West Ethiopia as revealed by microsatellite markers
Genetic Resources & Crop Evolution 60: 529–541. DOI 10.1007/s10722-012-9856-0
Abebe, W., Demissew, S., Fay, M.F., Smith, R.J., Nordal, I. & Wilkin, P. (2013)
Genetic diversity and species delimitation in the cultivated and wild guinea yams from Southwest Ethiopia as determined by AFLP (Amplified Fragment length Polymorphism) markers
Genetic Resources & Crop Evolution 60: 1365–1375. DOI 10.1007/s10722-012-9925-4