Dr Sandy Snyman
Genetic modification (GM) is a tool that plant breeders can use to introduce new traits into crops. GM is a technology that involves inserting DNA into the genome of an organism.
(A genome is the complete set of DNA in an organism, such as plant or animal). To produce a GM plant, new DNA is transferred into plant cells.
Usually, the cells are then grown in tissue culture where they develop into plants which contain the new DNA. We chatted to Dr Sandy Snyman, SASRI’s Principal Scientist: Biotechnology to share some insight into GM Sugarcane.
There is currently no GM sugarcane grown commercially in South Africa. However, SASRI is working on developing GM sugarcane that can tolerate the herbicide imazapyr, and resist stalk-boring insects such as eldana, sesamia and chilo. This is a lengthy process and, if goes as planned, the first GM sugarcane will be released to the SA sugar industry in 2032.
Is eating GM sugarcane from the field and drinking the juice safe?
Yes, it’s safe. The proteins in GM sugarcane are designed to target specific pests like eldana, sesamia and chilo, not humans or animals. These same proteins have been safely used in other crops, like Bt maize, which has been grown in South Africa for over 20 years. Extensive lab studies and field tests elsewhere have shown no harmful effects on people or animals, so you can enjoy GM sugarcane just like any other.
Will GM sugarcane varieties replace all other varieties?
No, GM sugarcane varieties will not replace all other sugarcane varieties. Farmers will always have a choice of which varieties to plant, depending on their specific farm needs. Initially, only one or two GM varieties will be available, but as these are used in SASRI breeding programmes, more options will emerge. However, farmers will still need to plant non-GM cane as part of an integrated pest management strategy to prevent eldana from developing resistance to the GM traits.
Will fields planted with GM sugarcane be demarcated?
After regulatory approval, there is no legal requirement to label GM cane fields. However, growers will need to track their GM fields for practical reasons. SASRI Biosecurity will need to monitor eldana levels and ensure ongoing performance of the GM varieties.
Will regular and GM sugarcane be separated at the mill?
This decision will depend on the mill crushing the cane, but sugar made from GM sugarcane will be labelled so that the consumer is aware.
Will I know if I am eating sugar made from GM sugarcane?
No, unless you read the label. Sugar from GM and non-GM sugarcane is identical, and no part of the sugarcane plant remains in the final processed products like sugar or molasses.
Will farmers need special permits to plant GM sugarcane?
No, once a GM sugarcane variety is commercialised, a General Release permit is issued, and farmers will not need any special permits to grow it. After rigorous testing, GM sugarcane is treated just like regular cane, with the only difference being the added trait or attribute. But during the development phase, SASRI researchers need permits from the GMO Registrar to conduct field trials.
Why is it taking so long to get eldana resistant cane?
Developing eldana-resistant sugarcane takes time. Whether through traditional breeding or GM technology, the process demands at least 10-12 years of rigorous testing. This ensures new varieties not only resist eldana but also perform well in the field, remain environmentally safe, and pose no health risks. It is a careful balance of innovation and caution to create a crop that is both resilient and reliable.
Can the technology be applied to other insects e.g. YSA?
Yes, GM technology can be applied to insects besides eldana. Researchers are exploring the use of other CRY proteins from the bacterium Bacillus thuringiensis (Bt) to enhance sugarcane’s resistance to pests like YSA and thrips — something not possible with traditional breeding methods.
When will Roundup-Ready GM cane be available?
We are not working on Round-up Ready (glyphosate tolerant) GM cane at SASRI. The herbicide tolerance that we are introducing into sugarcane is against imazapyr, which gives good control of creeping grasses. The main focus, however, is on eldana.
Will farmers use less chemicals if they plant GM cane?
Yes, GM sugarcane’s pest-resistance and weed-tolerance make it a greener choice for modern farming. It has ‘built-in’ pest control against specific pests, reducing the need for insecticides and its herbicide-tolerance allows farmers to reduce weed-killing sprays.