S14 - Session P5 - ToBRFV: from detection to disease resistance testing

Authors: Isabelle Serandat *, Sophie Perrot, Thomas Baldwin, Valérie Grimault

Tomato brown rugose fruit virus ( ToBRFV ) was first observed in 2014 and 2015 on tomatoes in Israel and Jordan, and outbreaks have since occurred worldwide . ToBRFV causes a wide range of symptoms and is a major concern for growers of tomato and pepper . ToBRFV has been classified as « Emergency measures » in France since the end of 2019. A very large number of seed samples have since been tested f or ToBRFV at GEVES . T he performance criteria of the method using primers developped by ISHI were studied. This method was used until mid-2020 and replaced after this date by the official French method of Anses . 3000 samples have been tested in 2020 , 13 were positive. Biological relevance was also investigated on a few samples by comparing to the sensitivity of the biotest , which raises questions for further studies. In 2019-2020, GEVES conducted the characterization of 2 ToBRFV isolates on tomato and pepper Tobamovirus differentials to establish the differential table published by ISF. GEVES also worked on the development of a resistance tests of tomato varieties for seed sector with the objective to be able to distinguish varieties with different levels of resistance (susceptible, intermediate resistant, resistant). This evaluation of the resistance is carried out by bioassays and RT-qPCR. Fisrt claims of varieties with resistance to ToBRFV are announced. D etection and evaluation of resistance will provide solution s for a better the control of this virus .