Portable DNA sequencers help African farmers fight crop disease

Scientists at The University of Western Australia are using new portable DNA sequencing technology for the first time in East Africa to help farmers fight the devastating impact of crop disease. 

Farmers struggling with diseased cassava crops can take immediate action to save their livelihoods based on information about the health of their plants, using the portable, real-time DNA analysis device.

The DNA handheld sequencer, called the MinION, was developed by British company Oxford Nanopore. It is being used to identify which strain of virus is destroying the cassava crops of farmers in Tanzania and Uganda as part of a collaboration of scientists and farmers, known as the Cassava Virus Action Project (CVAP).

Dr Boykin said because MinION was able to deliver the information in real time, compared to the usual three months, farmers were able to take action much faster.

With 800 million people worldwide dependent on the threatened cassava crop, the team now plans to expand the project, which aims to reduce the risk of community crop failure and help preserve livelihoods.

Cassava, a carbohydrate crop from which tapioca originates, plays a critical role in agriculture in developing countries. It is currently being devastated by several viruses causing two diseases; 'Cassava mosaic disease' (CMD), which led to major famines in the 1920s and 1990s, and 'Cassava brown streak disease' (CBSD), an epidemic of which is rapidly expanding in eastern Africa.

Both diseases, carried by the whitefly, prevent normal growth of cassava plants. This leads to significantly reduced harvests or even complete losses by farmers. The viruses make the plant inedible and unsellable and the crop must be destroyed to stop its spread.