Study on the susceptibility of tomato and Capsicum to an isolate of tomato mottle mosaic virus in China
Tomato mottle mosaic virus (Tobamovirus, ToMMV- EPPO Alert List) is a virus infecting tomato and Capsicum. While conducting the EPPO Pest Risk Analysis on ToMMV, there was little evidence of impact. Unlike in the case of tomato brown rugose fruit virus, there was no evidence of resistance breaking by ToMMV of the resistance genes/alleles Tm-22 for tomato and L for capsicum, which confer resistance to several tobamoviruses such as ToMV and tobacco mosaic virus (TMV).
During surveys in 2020, Tettey et al. (2022) observed tomato cultivars exhibiting severe viral symptoms in commercial tomato farms in Weifang (Shandong, China). Symptoms included mosaic and mottling of the leaf, necrosis of the peduncles, necrosis of the calyxes, brownish-green patches on ripened fruits, yellow striations around ripe fruits, yellowish-green patches on fruits, blistering and necrotic rings on ripened fruits. early and late necrotic patches on fruits. ToMMV was the only virus detected, and the isolate was named ToMMV-Shandong. In experiments, symptoms, including severe mottling and stunting, were observed after mechanical inoculation of this isolate to 8 commercial cultivars of tomato with Tm-22 resistance gene, and 7 commercial cultivars of Capsicum with L genes/alleles (specific alleles not determined), and systemic movement of the virus was shown. The authors note the need to screen tomato and capsicum lines to identify resistance to ToMMV and, in the case of Capsicum to identify the effective L alleles.
Sources
Tettey CK, Yan ZY, Zhao MS, Chao GE, Tian YP, Li XD (2022) Tomato mottle mosaic virus: Characterization, resistance gene effectiveness, and quintuplex RT-PCR detection system. Journal of Integrative Agriculture 21(9), 2641-2651. https://doi.org/10.1016/j.jia.2022.07.020
EPPO (2022) EPPO Technical Document No. 1088. Pest risk analysis for Tomato mottle mosaic virus. EPPO, Paris. Available at https://gd.eppo.int/taxon/TOMMV0/documents