Glycoalkaloid levels in potato tubers and leaves after intermittent plant exposure to ozone

Abstract

Irish potato vines of ‘Norland’ and ‘Kennebec’ cultivars were exposed to 387 μ/m3 ozone for 3 hr once every wk throughout their growth. Tubers of ‘Norland’ and ‘Kennebec’ were harvested at 120 and 140 days, respectively, from exposed and non-exposed plants. The experiment was conducted in 1977 and again in 1978. Ozone induced severe foliar injury to ‘Norland’ and slight injury to leaves of ‘Kennebec’ Tubers from ozone treated plants displayed a significant reduction (0.35 mg TTGA/100 g fresh weight tuber tissue) in tuber total glycoalkaloids (TTGA) when expressed on a fresh weight basis. However, since differences were not detected for TTGA on a dry-weight basis, the fresh-weight TTGA differences may only reflect variations in moisture content. In a separate experiment, both ‘Norland’ and ‘Kennebec’ were exposed to 488 μg/m3 ozone for 3 hr when the plants were 18 days old. When leaves were harvested three days later, no significant differences were detected between leaf total glycoalkaloid (LTGA) levels of treated and nontreated plants.