• Korean Journal of Environmental Agriculture
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• v.23 no.3
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• pp.128-132
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• 2004

Ozone effects were studied by plant growth chamber to evaluate the impact of ozone ($O_3$) on the physiology of two hot pepper, Capsicum annuum L., cultivars, 'Dabotab' and 'Buchon'. Forty-day old plants with $5{\sim}7$ leaves were exposed to $O_3$ of <20 and 150 nL/L for 8h/d for 3 days. Net photosynthesis and stomatal conductance were measured and foliar injury was described. Foliar damage due to the treated $O_3$ was different from the varieties. 'Dabotab' was most sensitive to $O_3$ and 'Buchon' was resistant. Symptom of ozone damage on the leaves was bifacial necrosis. Decreases of net photosynthesis by $O_3$ were 56% and 40% on 'Dabotab' and 'Buchon', respectively. Decreases of stomatal conductance by $O_3$ were 66% and 63% on each variety. $O_3$ damage on net photosynthesis was started at the low levels of light on the two hot peppers. In addition, assimilation-internal $CO_2$ concentration curves were not different from the two varieties. In conclusion, $O_3$ closed the stomata and decrease net photosynthesis on hot peppers regardless of the ozone sensitivity on leaf injury, but the difference of ecophysiological responses between the two varieties was not found clearly.