| Climate change means Africa’s food supply now largely depends on conventionally bred and genetically modified drought tolerant crops say scientists at the University of the Free State in South Africa
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| Sensationalist myth-making news stories about GMOs are scaring people and endangering the food chain say scientists at the University of the Free State in South Africa.
To feed the world during this time of climate change GMOs are a part of the answer they say. When you consume GMOs, (genetically modified organisms) your DNA cannot be altered as there are no mediated processes involved they say. Popular myth states that GMOs are harmful to humans and can alter you DNA when consumed. What is not well understood is that when foreign genes, from bacteria or organisms other than plants, are incorporated into a crop for any type of improvement, a process is necessary to mediate the transfer of the gene of interest from the organism into the crop. This mediation is not natural and can therefore not take place spontaneously. Therefore, when you consume GMOs, your DNA cannot be altered as there are no mediated process involved. Because South Africa is predominantly semi-arid, and water availability is a major limiting factor to crop production, the country has become a leader in GMO produced food, to ensure its ability to feed its growing population. The answer lies in genetically modified crops and breeding – wheat, maize and soybean production is already seeing remarkable crop improvements. In maize there has been remarkable progress in stress tolerance breeding in the last 10 years. Field-based breeding approaches have resulted in average breeding gains of around 100 kg per year per hectare under drought conditions. Plants that are drought tolerant are often also heat tolerant, as the tolerance mechanisms are similar. Advances with maize Prof Maryke Labuschagne, who holds the SARChI Chair in Disease Resistance and Quality in Field Crops at the UFS, explains what drought, heat and nitrogen resilient maize is: This means that the newly developed maize hybrids are genetically manipulated, through crossing and selection to tolerate drought, heat and low nitrogen. The plants are evaluated under stress conditions and the best ones are selected, and with consistent selection pressure there is a significant improvement in the stress tolerance. The stress tolerance is often related to physiological and morphological characteristics, which can be identified and selected. For example, drought tolerant hybrids can intercept more sunlight through increased leaf longevity and more erect leaves, a better uptake of nutrients and water through a more active root system, a decreased tassel size, and fewer barren plants. Genomics and genetic transformation are also tools that are increasingly being used to improve stress tolerance. Biofortification is the process of genetically improving the nutritional value of crops. The most successful examples of biofortification are yellow or orange maize, cassava, sweet potato and bananas. These biofortified crops have increased carotenoids, or provitamin A, which is converted to vitamin A by the body. Vitamin A deficiency is widely prevalent in Africa, causing blindness in severe cases. It is done through conventional breeding or transgenics. Other examples of biofortification are increased zinc and iron in crops, and improved fatty acid profiles. Biofortification is the only sustainable way to improve the nutritional status of especially poor communities, as the nutritional value is “built” into the crops, and is not lost, and no human intervention is necessary. “Most maize and soybean in South Africa contain GM (unless it is labelled as non-GM), so we are all consuming it in some form. In my opinion GM is here to stay, and it will significantly contribute to food security in Africa in the future,” says Labuschagne. The South African government has a stringent process before any GM crop is released. The advisory committee consists of a panel of scientists which evaluates all applications. There are various levels of release, such as trial release, where only trials are conducted under strictly controlled conditions; commodity release, where GMOs are used as food or feed, to commercial release for production. Potential GM varieties are tested for every possible kind of risk, and if a variety is released the public can be sure that there is no risk to humans or the environment from this variety, says Professor Labuschagne.
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