Potato Resistance to Cucumber Mosaic Virus is Temperature Sensitive and Virus-Strain Specific

Cucumber mosaic virus (CMV) is an important plant pathogen worldwide, which infects and causes yield losses to many solanaceous crops but rarely to potatoes. In the study reported here, we have tested the susceptibility of various potato genotypes to three different CMV strains, Pf-CMV and Fny-CMV, which belong to subgroup I, and A9-CMV, a member of subgroup II. Eight potato genotypes were found that could be systemically infected by at least one of the three CMV strains. Furthermore, although most potato cultivars were resistant to systemic infection at 24°C, all became infected systemically when inoculated plants were grown at 30°C. These results suggested that the natural resistance that most potato crops express to CMV might be overcome under high-temperature growing conditions following infection, and that CMV resistance in potato showed virus strain specificity.