VIEW ARTICLE

Effects of Air Pollutants on Nicotiana Cultivars and Species Used for Virus Studies. J. J. Grosso, Plant Pathologist, Plant Science Research Division, ARS, USDA, Beltsville, Maryland 20705; H. A. Menser(2), G. H. Hodges(3), and H. H. McKinney(4). (2)(3)(4)Plant Physiologist, Research Assistant, and Collaborator, respectively, Plant Science Research Division, ARS, USDA, Beltsville, Maryland 20705. Phytopathology 61:945-950. Accepted for publication 9 March 1971. DOI: 10.1094/Phyto-61-945.

Three tobacco cultivars (Nicotiana tabacum) and two (Nicotiana species, used for virus identification studies, were tested for susceptibility to air pollutants. The air pollutants used were (i) ozone; (ii) sulfur dioxide; and (iii) a mixture of both gases. Nicotiana rustica var. brasilia was the most susceptible cultivar to injury from individual gases, a gas mixture, and ambient polluted air. Nicotiana rustica var. brasilia displayed from 25 to 70% leaf injury when exposed to increasing ozone doses (10 to 30 pphm). Ozone injury to N. glutinosa fumigated at the same doses ranged from 10 to 60%. Samsun, Samsun (NN), and Xanthi cultivars were more resistant to ozone than N. rustica var. brasilia or N. glutinosa. Sulfur dioxide (ca. 45 pphm) added to an ozone (ca. 3.0 pphm) atmosphere induced a synergistic response evidenced as injury to all cultivars and species. Mixed gas injury was more acute on N. glutinosa and N. rustica var. brasilia than on Samsun, Samsun (NN), and Xanthi. Samsun and Samsun (NN) were more susceptible to sulfur dioxide (125 pphm) than N. glutinosa and Xanthi. Fumigations produced two injury syndromes: (i) light or dark punctate flecks, on upper leaf surfaces; or (ii) bifacial tissue collapse.