Origin of Bel-W3, Bel-C and Bel-B tobacco varieties and their use as indicators of ozone

• Published in: Environmental pollution (1987) 1991, Vol.74 (4), p.264-291
• Main Author: Heggestad, Howard E.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Non agrochemicals pollutants; Phytopathology. Animal pests. Plant and forest protection; Pollution effects and side effects of agrochemicals on crop plants and forest trees. Other anthropogenic factors; Pollution effects. Side effects of agrochemicals
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/0269-7491(91)90076-9

Since 1962, the tobacco variety Bel-W3 ( Nicotiana tabacum L.), has been used in many countries as an indicator of the presence of phytotoxic concentrations of O 3. It is super-sensitive to O 3 and may produce easily recognizable symptoms for several weeks on the new, fully expanded leaves. Bel-B and Bel-C, tolerant and sensitive to O 3, respectively, are sometimes used along with Bel-W3. Information is provided on the origin and nature of these varieties. This includes their use as indicators of elevated O 3 concentrations, strength and limitations, and the inheritance and nature of resistance to O 3 in Bel-B. The varieties were the product of research initiated in 1957 to determine the cause and to reduce losses from tobacco weather fleck. Bel-C and Bel-B display the classical upper leaf surface injury; whereas, Bel-W3 develops primarily bifacial lesions. Data are provided to show differences in the amounts of acute and chronic injury on each variety when exposed to different O 3 exposure doses in controlled environments and under field conditions. There is discussion of the influence of environmental factors on response to O 3 by the varieties and the possibility of synergistic action of O 3 and SO 3 when tobacco is exposed to mixtures of these gases. The methods and results obtained with Bel-W3 in the Dutch National Monitoring Network for Air Pollution are presented in detail. Use of Bel-W3 world-wide as an indicator of elevated O 3 concentrations has been a significant factor in increasing the awareness of O 3 as a pollutant.