HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Petolino, J. F. Articles by Aycock, M. K. Search for Related Content PubMed Articles by Petolino, J. F. Articles by Aycock, M. K., Jr. Agricola Articles by Petolino, J. F. Articles by Aycock, M. K.

Leaf Injury and Peroxidase Activity in Ozone-Stressed Tobacco Cultivars and Hybrids¹

Ozone-induced leaf injury and peroxidase activities in tobacco (Nicotiana tabacum L.) were studied under greenhouse and field conditions to determine if the stimulation in peroxidase activity could be used as a genetic marker for ozone induced biochemical stress. Greenhouse experiments involving four cultivars and six F₁ hybrids of Maryland tobacco were conducted during 1979 and 1980 and field experiments involving seven cultivars and 21 F₁ hybrids from a diallel set of crosses were grown in two environments at the University of Maryland Tobacco Experimental Farm during the summer of 1980. Plants were exposed to either charcoal-filtered air or charcoal-filtered air plus added ozone in partially open.topped fumigation chambers. Ozone levels used in the greenhouse exposures were 8.1 x 10^–6 mol m ^–3 for 6 h day^–1 for 2 days. Field ozone exposures were 4.9 x 10 ^–6 mol m^–3 for 6 h day^–3 for 9 days. Visual leaf injury ratings and peroxidase activities were determined for the various treatments. Ozone exposure resulted in considerable visual leaf injury. All cultivars and hybrids exhibited some degree of foliar damage and significant differences were observed among the entries in both greenhouse and field exposures. ‘Md 872’ was consistently the most tolerant entry while ‘Md 59’ and ‘Bel-W3’ appeared most sensitive with respect to foliar damage. Peroxidase activity was significantly higher in plants exposed to ozone as compared to the controls. Stimulation in peroxidase activity upon exposure to ozone was evident in all entries regardless of the amount of visual foliar injury which suggests that this enzyme may not be a reliable marker for ozone tolerance in tobacco. There was a general lack of genotype x environment interaction for visual responses to ozone stress; however, peroxidase activity appeared to be highly sensitive to environmental changes.

Key Words: Air pollution • Stress physiology

² Graduate assistant (Present address: Agronomy Dep., Univ. of Kentucky, Lexington, KY 40548); associate professor and professor, respectively, Dep. of Agronomy, Univ. of Maryland, College Park, MD. 20742.

Received for publication December 29, 1982.