Searching for new resistance sources to tomato yellow leaf curl virus within a highly variable wild Lycopersicon genetic pool

The high variability found among Tomato yellow leaf curl virus (TYLCV) isolates from different geographical areas makes progress in breeding for TYLCV resistance slow. By using Agrobacterium-mediated inoculation, we have identified several new resistant sources to TYLCV within a extraordinarily variable wild Lycopersicon gene pool, collected in semidesert areas of Ecuador and Peru changed into wet by “El Nińo”. This screening assay revealed a high susceptibility within L. esculentum and L. pennellii, but different levels of resistance within L. pimpinellifolium and L. hirsutum. Resistance level was related to the collection place, being concentrated in accessions collected in Northern Peru (Piura province). Agroinoculation allowed the selection of 4 Lycopersicon pimpinellifolium and 2 Lycopersicon hirsutum accessions with higher level of resistance than accessions of these species previously reported, avoiding interference due to vector resistance mechanisms reported in both species. These new resistance sources will be included in pyramiding strategies aimed at obtaining durable resistance to TYLCV.