Whiteflies are a significant pest in greenhouse tomato systems. Not only do the tiny bugs consume sap, but they also leave sticky ‘honeydew’ which can attract mould. Even worse, the whiteflies can spread viruses as they move from plant to plant. Scientists are looking to wild tomatoes to learn more about whitefly resistance.
When given a choice between wild and modern tomato varieties, whiteflies show a strong preference for modern tomatoes, landing on commercial cultivars 80 per cent of the time. Whiteflies appeared to be less attracted to the wild tomatoes and the insects that landed on the wild tomatoes quickly left after consuming sap. When the whiteflies were given no choice but wild tomatoes, they consumed sap but at a lower rate than whiteflies on commercial tomatoes.
It appears that the wild tomatoes have multiple forms of resistance. The plants are less attractive to the whiteflies so the whiteflies are less likely to land on them. If a whitefly begins to suck up the sap, the sap has an effect similar to clogging up the eating apparatus of the whiteflies.
The researchers recommend breeding wild tomatoes with modern cultivars to try to get a tomato with the modern growth pattern and size, but the resistance of wild tomatoes. The scientists advocate preserving wild varieties of other food crops to find similar forms of resistance to pests and diseases.
Source: Novel resistance mechanisms of a wild tomato against the glasshouse whitefly. Thomas McDaniel, Colin R. Tosh, Angharad M. R. Gatehouse, David George, Michelle Robson and Barry Brogan. Agronomy for Sustainable Development. Volume 36, Page 14, March 2016.
- Janet Wallace