The reaction to Tomato spotted wilt virus (TSWV) was evaluated in 94 accessions of Nicotiana, originating from the Institute of Soil Science and Plant Cultivation tobacco germplasm collection in Puławy, Poland. Tests for resistance were conducted under greenhouse conditions using single TSWV isolate collected from tobacco plantation in Lublin district, Poland. The presence of the virus was verified using DAS-ELISA. SCAR markers associated with TSWV resistance gene were applied. The members of the section Alatae, the genus Nicotiana: N. alata, N. forgetiana, and Nicotiana x sanderae as well as N. tabacum cultivars: ‘Polalta’ and ‘Wiktoria’ with the TSWV resistance gene introduced from N. alata, displayed the hypersensitive reaction (HR) against TSWV (grade 0 on symptom intensity scale). In some of those accessions, the virus spread from the initially infected areas eliciting systemic hypersensitive reaction (SHR). Five accessions of N. alata and three of Nicotianaxsanderae were composed of 6.3–50.0 % of plants in which SHR symptoms appeared. In all of N. forgetiana plants HR reaction was followed by systemic infection (SHR). In N. tabacum ‘Wiktoria’ 21.1 % of plants showed HR reaction, while the remaining were susceptible (S). All of the genotypes which responded with HR or SHR reaction to TSWV infection demonstrated the presence of SCAR markers linked to the resistance gene. The remaining eighty tested accessions were identified as being susceptible upon exposure to TSWV.

Growing resistant cultivars is the best method of protecting the crops against Potato virus Y (PVY). There are a few sources of PVY resistance/tolerance in tobacco acquired through mass selection, X-ray induced mutagenesis and introgressions from wild Nicotiana species. Here, we compare major sources of PVY resistance/tolerance in inoculation tests using ten PVY isolates collected in Central Europe (Poland and Germany) and differing with their virulence. The diversity of collected isolates was confirmed by DAS-ELISA tests and two PCR assays targeting the most common recombination sites in the PVY genome. We used these isolates in inoculation tests on five resistant cultivars 'V.SCR', 'PBD6', 'TN86', 'VAM', 'Wiślica', a tolerant breeding line 'BPA' and four susceptible cultivars 'BP-210', 'K326', 'NC95', 'Samsun H'. None of the tested cultivars/breeding lines showed universal resistance against all ten isolates. However, 'VAM' and 'Wiślica' appeared to be the most effective sources, as they showed no symptoms and gave negative DAS-ELISA tests for four out of ten tested PVY isolates. In contrast, tolerance of the breeding line 'BPA' was effective against all tested isolates, because inoculation did not lead to development of full disease symptoms in that breeding line.