Tomato genetic resistance to tobamoviruses is compromised
An outbreak of a new disease infecting tomato plants (Solanum lycopersicum) which carry the tobamovirus resistance gene Tm-2 occurred in southern Israel during the autumn of 2014. Symptomatic plants showed a mosaic pattern on leaves accompanied by narrowing of leaves and yellow spotted fruit. It was found that the causal agent is a new tobamovirus that was identified earlier in Jordan and named Tomato brown rugose fruit virus (ToBRFV). The virus is fast spreading in many tomato growing-areas in Israel, and since then it was found to be spreading rapidly world-wide. According to tomato growers, ToBRFV induces severe yield loses due to reduction in plant vigor and fruit quality. Here, we assayed the effect ToBRFV has on tomato yield and yield components of four different tomato genotypes, which included two near-isogenic lines, one with and one without the known tobamovirus resistance gene Tm-22, a tolerant genotype and a resistant genotype. Two yield experiments that were carried out at two different geographical locations were conducted. In each experiment, the yield performances of ToBRFV-inoculated plants were compared to those of control non-inoculated plants of the same genotype. It was found that the virus is able to induce a yield reduction of 15-55% regardless if the plants carry the resistance gene Tm-22. The resistant and tolerant genotypes also suffered a yield reduction following inoculation with ToBRFV, but the reduction was not statistically significant for the tolerant genotype in both trials, while for the resistant genotype in one trial it was statistically significant and not so in the other trial.
Avni, B., Gelbart, D., Sufrin-Ringwald, T., Zinger, A., Chen, L., Machbash, Z., Bekelman, I., Segoli, M., Dombrovsky, A., Kamenetsky, R., Levin, I. and Lapidot, M. (2021). Tomato genetic resistance to tobamoviruses is compromised. Acta Hortic. 1316, 89-98
ToBRFV, resistance, tomato, yield, Tm-2