Parasitizing Tobacco Cultivars in Brazil.

Foliar nematodes ( spp.) are known to be parasites of tobacco in restricted areas, but symptoms caused by in tobacco are not well characterized, despite the great importance of this nematode worldwide. This study aimed to evaluate the host reaction of four cultivars (Comum, Xanthi, Samsun, and TNN) and cultivar Comum to and to characterize the symptoms and the parasitism of this nematode. Two experiments were conducted under greenhouse conditions with controlled humidity and temperature, in which the plants were inoculated with 600 . At 30 days after inoculation (DAI), nematodes present in the soil, roots, and shoot parts were extracted, and roots and shoot tissues were stained with acid fuchsin. A high number of was obtained per gram of shoot tissues (125 to 2,169 nematodes), and severe symptoms were observed in leaves and inflorescences of all cultivars. The symptoms included foliar distortion and deformation, necrotic spots delimited by the veins, flower abortion, and poor development of plants. In addition, was observed to penetrate tobacco roots at 30 DAI, and nematodes were also observed in the foliar mesophyll, inflorescences, and stems, a parasitism that has not been previously reported in tobacco plants. The disease caused by in tobacco could be a concern for growers in southern and northeastern Brazil because this nematode can cause severe damage to the marketable leaves of tobacco, reducing its commercial value.