Cutting-edge Dutch biotechnology company Genetwister is investing in South Africa, in a strategic partnership with Capespan, a major SA fruit exporter. is involved in various agricultural research projects that could potentially offer great practical value to SA fruit farmers.
“Fruit exports are an important part of the Western Cape’s economy, and the only way to remain competitive is to stay at the forefront of industry technology,” says Dr Reinette Champanis, operations manager for Genetwister Africa in SA. Fundamental research at institutes and universities is vital to Genetwister’s projects, but sometimes there’s a gap between research and its practical application in the field, says Dr Genetwister aims to bridge that gap by working closely with research institutes and commercial companies that can use the research findings. “We’re almost ready to commercialise a defect-prediction model in fruit,” Dr Champanis says.
“By measuring the expression levels of certain genes we have identified, we can establish links to specific types of defects. For example, internal browning in apples is difficult to deal with as it’s undetectable during harvest and packaging, but when fruit reaches its export destination, it isn’t marketable.
We’ve identified the genes responsible for the ripening process in different cultivars and are identifying the ones responsible for the various disorders. By measuring their expression levels, we know at which level internal browning is likely to occur, and producers can make alternative marketing plans before it’s too late.”
The same goes for grey pulp in avocado pears and other disorders in various fruits. Optimum harvesting time can also be determined on a molecular level. Traditionally a producer would use appearance, taste and texture as indicators of ripeness. Laboratory tests base ripeness indexing on sugar, acidity, starch and texture, but these tests aren’t as accurate or sensitive as molecular analysis. U sing molecular science, marker-assisted breeding programmes can enhance propagation of new cultivars, significantly speeding up the propagation of enough trees for the industry. Producing plants that are free of microbes or viruses enables growers to start with the best possible material.
“We’re currently discussing the possibilities with tree growers, and the response has been very positive,” says Champanis. Now that the defect identification project is up and running, marker-assisted breeding will be the next priority. Other tissue culture techniques include ovulo rescue – removing embryos from seedless parents before they abort – which makes it possible to introduce new seedless grape varieties.
A competitive advantage Analysing and describing fruit on a molecular level offers marketing advantages too. Producers can now describe their crops in an objective and quantifiable manner. European buyers will know exactly what they’re buying, where it comes from and what quality level they can expect on arrival. E uropean supermarkets have already indicated their interest.
This technology is not available in countries our fruit industry competes with, and Dr Champanis isn’t aware of any similar research at the level of commercial application being conducted elsewhere. Contact Dr Reinette Champanis on (021) 887 5485. |fw
