Overseas projects in virus research

The ambition is to increase potato yields - and importantly Kenyan farmer's incomes - by establishing systems to support virus-free potato seed tuber production.

Monsanto Fund Grant to strengthen potato production systems in Kenya

Potato (Solanum tuberosum L.) is the second most important food crop in Kenya after maize. Potatoes play an important role in food security as they are traded locally and have high nutritional value. Consumption per capita is approximately 89kg per year and rising. There are 5 million potato producers and the potato industry was worth approximately 10 billion KSh (£100 million) in 2007. However, average yields are less than 10 t/ha.

Virus diseases are the major cause of degeneration of seed potato stocks because in potatoes (and other vegetatively propagated crops) once a plant is infected by a virus it cannot be ‘cured’. Infected plants produce virus infected tubers and infected progeny plants. Aphids transmit viruses from infected plants to clean stocks during the growing season thus very quickly infection builds up in the crop unless aphids can be controlled.

The biggest limitation on potato production in Kenya is lack of supply of disease-free certified seed tubers. Less than 1% of growers have access to certified seed. There are bottlenecks in multiplication of sufficient disease-free tubers to supply the demand, as a result growers use home saved seed or that obtained from local markets which is often diseased. In a visit to the Mount Kenya potato producing regions of Buuri and Meru we saw newly emerging crops displaying symptoms of virus diseases in >60% of plants. Potato varieties with traits such as high levels of virus disease resistance, drought tolerance and good processing qualities are required.

We have surveyed virus incidence in potato crops in the major potato growing regions and found high levels of virus in all areas. We have also found that recombinant strains of potato virus Y (NTN and Wilja) are present in several regions. We have conducted aphid monitoring and identified some regions with low aphid pressure that might be suited to seed tuber multiplication to increase seed production. Another aspect of the proposal is to provide tissue culture material of new varieties with desirable traits (PVY resistance, drought tolerance, better fry qualities). This material has been multiplied in Kenya at KARI Tigoni and is currently undergoing National Performance Trials. We will work with commercial growers, government and other agencies and researchers to help support seed tuber production, providing training and demonstrating the benefits of growing crops from ‘clean’ seed to increase yields and to increase farmers’ incomes in a self-sustaining manner.

The project involves a collaboration between the James Hutton Institute and three organisations in Kenya. Lead partner at the James Hutton Institute is Professor Lesley Torrance, Virologist and head of the Cell and Molecular Sciences Group. The lead Kenyan partner is Dr Hassan Were (Virologist), Department of Biological Sciences, Masinde Muliro University of Science and Technology, Kakamega. Other partners are Dr Florence Olubayo (Entomologist) University of Nairobi and Dr Jackson Kabira (Potato Breeder) Director and Head of Potato Programme, National Potato Research Centre, KARI Tigoni.

Institute virologists link with China

CMS scientists Lesley Torrance, Michael Taliansky and Stuart MacFarlane visited Zhejiang Academy of Agricultural Sciences, Hangzou, China in late 2010 to take part in a seminar day and exchange ideas to enable the establishment of closer scientific collaboration between the James Hutton Institute and ZAAS. A Memorandum of Understanding signed by the two Institutes has now resulted in the formation of an International Joint Laboratory for research into Sustainable Pest and Disease Control and plans are underway for exchange of scientists and collaborative research in projects of mutual interest.