Seed World

Enza Zaden’s First Trial Confirms High-Level ToBRFV Resistance

In 2020 Enza Zaden announced the discovery of the tomato brown rugose fruit virus (ToBRFV) high resistance gene, a complete solution for ToBRFV. Since the announcement, the company has worked hard with resistant trials material achieving excellent results.

“We see no symptoms at all in the plants, while the disease pressure is very high,” says Oscar Lara, senior tomato product specialist, about the first trials in Mexico.

High Resistance ToBRFV Genes

At the trial location in Mexico, the high resistance (HR) varieties are placed next to susceptible ones. There you can clearly see the difference. The susceptible tomato varieties show different foliage disorders such as a yellow mosaic pattern. The affected plants also stay behind in growth.

“You can clearly see how well our highly resistant varieties withstand ToBRFV,” says Oscar Lara in the latest Enza Zaden video. “In comparison to the plants of susceptible varieties, the resistant ones look very healthy with a dark green colour, show no symptoms at all and have good growth. All our trialled HR tomato varieties do not show any symptoms at all.”

Enza Zaden is running parallel tests in different countries with varieties with high resistance to ToBRFV.

“Our trials in Europe, North America and the Middle East show that we have qualitatively good tomato cultivars with a confirmed high resistance level,” says Kees Könst, crop research director. “This is exciting news for all parties involved in the tomato growing industry. We know there is a lot at stake for our customers, so we continue to work hard to make HR varieties available for the market. We expect to have these ready in the coming years.

“With an intermediate resistance (IR) level, the virus propagation is delayed but ToBRFV can still enter tomato plants – plants that may eventually show symptoms,” says Könst. “With a high resistance level, plants and fruits do not host the virus at all. This means they won’t be a source for spreading the virus and that the detection test will come back negative. Growing a variety with high resistance can be the difference between making a profit or losing the crop.”

Source: Enza Zaden