• Research

Understanding sex in the white Guinea yam

Improving food security in West and Central Africa through the creation of genomic resources for the white Guinea yam.

Image credit: David Marshall, James Hutton Institute, UK

White Guinea yams at a market in Benin, Africa

Project summary.

Led by: Haerty Group

Start date: October 2014

End date: September 2018

Duration: 4 years

Grants: BBSRC Training Grant and BB/J004669/1

Value: £94,126

Yam is a traditional staple crop of great agricultural, cultural and economic significance to Central and West Africa, featuring heavily in Chinua Achebe’s modern literary classic “Things Fall Apart” as a cornerstone of Igbo culture. Yams are a staple part of the Nigerian diet, with Nigeria accounting for around 70% of world yam production, but at current rates of consumption demand is beginning to outstrip supply. Nigeria is set to become the third largest country in the world by 2050, with a population of over 300 million, surpassing the US. It is vital we work on breeding improved crops to help feed these and the other 9 billion people expected in 2050.

As part of the EDITS-Yam international collaboration, we aim to assist with the production of a reference sequence for the most important yam in the region, the white Guinea yam (Dioscorea rotundata Poir.), which can then be used to generate molecular markers for agronomically important traits for use in genome-assisted breeding of improved yam varieties.

We will also investigate the evolutionary history of sex in white Guinea yam, as this is a fundamentally important trait that will not only assist yam breeding, but also answer evolutionarily important questions in other species.


Many yam species are known to be diecious in nature, having both male and female individuals, which is a rare trait found in only 5-6% of flowering plants. Despite this, yam has been neglected as an orphan crop, with limited genomic resources available and no comprehensive phylogenetic or evolutionary studies that could be used to assist the breeding of improved varieties.

From this project we will gain a better understanding of the evolutionary history of this vital, yet neglected, staple crop. The reference sequence for the white Guinea yam will open the door towards genetic improvement in yam and other agronomically important species, boosting food security and increasing income for small hold farmers in West and Central Africa and further afield.


All raw data used during the project and the reference sequences have been made publicly available.

New Guinea yam reference Genome and raw data
The D. rotundata reference genome and datasets used during this study are available via BioProject Accession Number: PRJDB3383
New Guinea yam genome annotation
The D. rotundata gene/protein sequences and gff3 annotation files.


Prof. Ryohei Terauchi, Kyoto University / Iwate Biotechnology Research Centre, Japan

Dr. Robert Asiedu, The International Institute of Tropical Agriculture, Nigeria

Sophien Kamoun, The Sainsbury Laboratory, UK

Impact statement.

Deciphering the yam genome is of vital importance, not only because of its economic and cultural significance, but because unlike other staple crops such as wheat, maize and rice, the crop is relatively undomesticated.

Understanding the genomics and evolutionary history of this crucial staple crop will help farmers increase the yields and sustainability of yams, as well as other economically important tropical food crops.

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