When Arab traders introduced cassava — a nutty-flavoured root vegetable, rich in vitamins, minerals and protein — in the late 1860s to what is now Uganda, little did they suspect that it would become one of the country’s most important staple food crops in less than a century with almost three quarters of farming households growing cassava. Loved and deeply incorporated into local cuisine, cassava today is threatened by brown streak disease (CBSD). By making the cassava flesh inedible, CBSD can reduce production by 70 per cent, undermining food security and hurting the livelihood of farmers dependent on the crop for food and income.
Conventional breeding methods have been too slow to produce varieties that can withstand the disease, so the National Crops Resources Research Institute (NaCRRI) in Uganda turned to a nuclear-based breeding technique and is teaming up with the IAEA and the Food and Agriculture Organization of the United Nations (FAO) to develop cassava varieties that are both resistant to the virus and high yielding. Cassava, as a vegetatively propagated crop, has a narrow genetic base. By irradiating cassava tissue, the natural evolution process of induced mutations was accelerated, increasing the diversity of varieties, including some with new traits.
So far, 42 new cassava lines have been developed through this method, and four of them have initially shown some level of resistance to CBSD — the focus now is on developing them further for higher yields. As trials continue, scientists in Aura, Uganda, are eager to see the outcome.
“Following a series of CBSD attacks in 2004, when the first symptoms were detected, the varieties we were cultivating and using in traditional breeding for further improvement were susceptible to the disease. Now by using nuclear breeding techniques, our farmers may once again see hope in growing cassava plants, which are not affected by CBSD,” said Emmanuel Ogwok, Senior Research Officer at the NaCRRI of the National Agricultural Research Organisation in Uganda and a lecturer at Lira University.
By using nuclear breeding techniques, our farmers may once again see hope in growing cassava plants, which are not affected by CBSD.
