Modern breeding techniques of potato

4% of the worldwide potato production is harvested in Africa by thousands of small-scale farmers, mainly women. In Africa, yields are varying between 6 to 10 tons per hectare while the global average is approximately 17.4 tons/ha. Since the late 1970s, potato production areas have expanded in Africa nearly five fold while the yields only slightly increased. There are many reasons why the average potato production remains rather low: (1) Farmers have limited access to quality seed potato, (2) Monocropping results in more diseases and lower yields, (3) Diseases are spread fast because seeds sourced from markets or farmer’s own field are also prone to diseases and (4) Farmers have limited knowledge on how to select quality seed or use good agricultural practices. Finally, also climate change will have an important impact on potato production; due to heat and water stress, potato yields in most African countries will be at risk.

A very important potato disease in Africa and Flanders, but also worldwide, is late blight of potato due to infection with Phytophthora infestans. This disease is caused by water mould and destroys leaves, stems and tubers. Losses range from 22 to 100% and use of fungicides to control late blight disease costs 10-25% of the total sale for an average potato farmer in Africa. Both CIP and UGent/VIB are developing potato varieties that are resistant to late blight. This can be done by conventional breeding. During this procedure, resistance genes from wild relatives are transferred to the local varieties during several crossings. However, transferring resistance into commercial varieties by conventional breeding takes a lot of time. It took for example 45 years to release the late blight resistant Bionica potato. Also, new resistant varieties have not held long before new Phytophthora infestans strains could overcome single resistance gene. Therefore, both in Flanders (by VIB/UGent) and Africa (by CIP/NARO) late blight resistant potato varieties are being developed by biotechnological approaches using several resistance genes info farmers preferred varieties. New breeding techniques, in particular gene editing, have recently been applied to potato to produce improved varieties. Biotechnology offers the potential to rapidly develop resistant varieties that could be readily adopted and contribute to food security and income.

Once a promising new potato variety is created, on farm and on site evaluation is necessary. This involves multi-site evaluation, proper registration and, in particular for GM plants, also a safety evaluation and risk assessment should be performed. In 2016, 13 African countries either planted, actively evaluated field trials or transitioned to grant approvals for the general release of various biotech crops (Burkina Faso, Cameroon, Egypt, Ethiopia, Ghana, Kenya, Malawi, Mozambique, Nigeria, South Africa, Sudan, Swaziland, Tanzania and Uganda). Field trials are not only an important step in the research phase to demonstrate that the plants acquired the desired trait but are also an important source of information for safety evaluation and risk assessment. Prior to commercialization, the developers of GM crops or their derived foods must test them for safety and perform a thorough risk assessment. These tests follow protocols and standards established by international organizations and must comply with national and international regulatory frameworks. The case of the regulatory process to release gene-edited crops is less clear but will be important to address from both a science perspective (what really needs to be tested with regards to risk assessment) and applicable regulatory framework.The biotechnology regulatory policy in Africa is very complex. It is imperative for research institutes to be aware of the different regulatory frameworks and understand how to perform a reliable safety assessment at every step of the development process.

Additionally, once a new potato variety is developed, it is also important to communicate the findings well, not only to the scientific community, but also, and even more importantly, to the farmers, the public and the policy makers. Therefore, a good communication strategy should be developed.