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02 January 2025
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Story Gerda-Marie van Rooyen
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Photo Supplied
Leading the research in South Africa is Prof Linus Franke from the Department of Soil, Crop and Climate Sciences.
Scientists are actively pursuing the successful breeding of diploid hybrid potatoes from inbred lines. This is expected to revolutionise potato breeding as it holds the key to rapid genetic progress. It will introduce new varieties for commercialisation through seed. Currently, existing potato variants have a gene that renders self-pollinated seeds infertile.
Prof Linus Franke, an academic in the Department of Soil, Crop and Climate Sciences at the UFS, is leading the research in South Africa. “This technology allows the production of genetically uniform potato seed that is easy to transport and largely disease-free.” He says this differs from conventional breeding whereby only vegetative propagation is possible due to tetraploid varieties in potatoes. It also risks carrying pests and diseases from one generation to the next – leading to the accumulation of pests and diseases with each round of multiplication.
Seed innovation
Prof Franke explains that Solynta BV, a seed company based in the Netherlands that produces potato varieties that can be grown from seed, has included South Africa in their research efforts because it is one of Africa’s largest producers and exporters. Through his academic relationship with Wageningen University and Research, a Dutch institution renowned for its agricultural endeavours and food production, the UFS became involved in researching hybrid potatoes grown from seed.
Diploid seeds containing two sets of chromosomes allow easier gene manipulation to increase predictability and speedier genetic progress. The breeding approach enables the incorporation of tolerance to pests, diseases, abiotic stresses (cold, heat, drought) and other desired genetic traits.
Although Prof Franke is optimistic about this research, he is not blind to disadvantages. “Potato seeds are tiny and have little energy reserves, making it harder to grow potatoes from seed than from tubers.” He says potatoes from seed will take longer to cultivate than tubers, as farmers need to grow plantlets from seeds first, adding six weeks to the growing period. “It is possible that commercial farmers can grow potatoes directly from seed. Alternatively, perhaps more likely, specialised growers will produce tubers of potatoes from seed; these tubers are then sold as seed tubers to other potato farmers, who then continue their normal practices of producing potatoes for the market from tubers.”
Financial benefits
Prof Franke says farmers have reason to get excited. “Seed potatoes will reduce input costs, as varieties with enhanced tolerance to pests and diseases require less pesticides. Planting one hectare of potatoes requires three to four tonnes of potato tubers, but only one 25 g packet of potato seeds.” Since potatoes are a more valuable commodity than maize, this technology might also increase farmers’ income potential.
Childhood obesity should be curbed early
2017-03-15
Serious intervention by parents is required to deal
with childhood obesity. Prof Louise van den Berg and
a group of final-year PhD students worked on a study
about the prevalence of obesity in six-year-olds in
South Africa.
Photo: Supplied
If your child is overweight when they start school at the age of six, unless you do something about it at that point, the indications are they are going to be overweight teenagers and obese adults. This is according to University of the Free State’s Prof Louise van den Berg.
Evidence has shown that overweight children and teenagers have a greater risk of developing lifestyle diseases such as type 2 diabetes, hypertension and cardiovascular disease later in life, and dying prematurely.
Obesity is a global pandemic rapidly spreading among adults and children, in developed and developing countries alike.
Dr Van den Berg worked with Keagan Di Ascenzo, Maryke Ferreira, Monja-Marie Kok, Anneke Lauwrens, all PhD students with the Department of Nutrition and Dietetics, to conduct the study. Their research found that children who are overweight by the time they turn six should be screened for weight problems.
Why six-year-olds?
Children who are overweight between the ages of two and five are five times more likely to be overweight when they are 12. There are two periods in a normal life cycle when the body makes new fat cells. The first is in the uterus and the second is around the age of six. The second phase lasts from the age of six to puberty.
The study assessed the prevalence of obesity in six-year-olds as part of a campaign in South Africa to raise awareness of the problem among parents and educators.
A total of 99 children were chosen from seven schools in Mangaung, the capital city of Free State. The schools were chosen from quintile four and five schools, which when measured by their own resources and economic circumstances, are well resourced and serve largely middle-class and wealthy communities.
The children’s weight, height and waist circumference were measured and used to calculate a body mass index score and waist-to-height ratio. Both these figures are good predictors for future lifestyle disease risks such as type 2 diabetes, hypertension and cardiovascular disease. A person with a good waist-to-height ratio can wrap a piece of string equal to their height around their waist at least twice.
When the children had a higher body mass index, they also had an increased waist to height ratio. The study found one in four children from the schools surveyed were overweight when they started primary school.
Nipping the fat in the bud
Although there are many factors that play a role in preventing childhood obesity, parents’ perceptions of their children’s weight play an important role. A recent study found that more than 50% of parents underestimate the weight of their obese children. These parents remain unaware of the risks their children face and are not motivated to take any action.
At least half of the parents whose children are overweight struggle to recognise their children’s weight problems fearing that they will be labelled or stigmatised. By the time they turn six overweight children should be referred to dieticians and nutritionists who are qualified to guide their parents in getting them to eat well and be more physically active at pre-primary and primary school.
The high prevalence of weight problems among six-year-olds found in this study is an urgent call to healthcare professionals to step up and empower parents, educators and children with the necessary skills for healthy dietary practices and adequate physical activity.