Screening of wild tomato species and interspecific hybrids for resistance/tolerance to Tomato brown rugose fruit virus (ToBRFV)

Tomato (Solanum spp.) is the second most-consumed vegetable after potato and grown all over the world. Tomato brown rugose fruit virus (ToBRFV) was first identified in 2014 on tomato plants, since then it has been reported in many countries. It is a significant threat to tomato production. This work aimed to identify the disease resistance source(s). To achieve this aim, a total of 44 tomato materials including 28 accessions of eight wild species, two accessions of Solanum arcanum Peralta, S. pennellii Correll, and S. sitiens I.M. Johnst, seven accessions of S. chilense (Dunal) Reiche, fve accessions of S. pimpinellifolium L., four accessions of S. habrochaites S. Knapp & D.M. Spooner, three accessions of S. peruvianum L., one accession of S. chmielewskii (CM. Rick et al.) D.M. Spooner et al. and S. huaylasense Peralta, 5 cultivated tomatoes (S. lycopersicum L.) and 11 interspecific F1 hybrids derived from S. habrochaites and S. pennellii were tested with ToBRFV isolates by using the biological testing method. Mechanical inoculation method was used for biological testing. ToBRFV was inoculated to 10 plants with 2-3 true leaves two replicates for each genotype. As a result, S. pimpinellifolium (LA1651), S. penellii (LA0716), and S. chilense (LA4117A, LA2747) were found tolerant to ToBRFV with the lowest disease severity index (DSI) with 19.6%, 28.3% and 35.0%, respectively. Also, molecular genetic analysis of the plant material by using molecular markers revealed that there was no interaction between other virus resistance genes (Tm-22 and Tm-1) and ToBRFV resistance. These wild tomato species identified in the present study are valuable genetic resources to develop new resistance cultivars for ToBRFV resistance in tomato breeding programs. Key words: Resistance, ToBRFV, tomato, wild species.