Pažemio ozono ir ultravioletinės-B spinduliuotės kompleksinis poveikis valgomojo ridikėlio (Raphanus sativus L.) augimui bei fotosintezės pigmentams.

Research was carried out in growth chambers of controlled environment at Laboratory of Plant Physiology, Lithuanian Institute of Horticulture. There was investigated differential and integrated impact of ozone and UV-B radiation on radish plants (Raphanus sativus L.), cv. `Žara'. We followed the assumption that if plants treated with lower 03 concentration or UV-B radiation during the adaptation period and during the main impact period exposed to the same or other stronger factor distinguished by better indices as non-treated plants; it indicated that plants were adapted to the investigated stressors impact. The results of investigations of radish adaptation to complex ozone and UV-B irradiation exposure indicate, that no cross-tolerance emerge in radish plants: they do not adapt neither to the other stressor of higher intensity, nor to the same stressor of higher intensity. Moreover, these stressors strengthen each others negative effect. Relatively low ozone concentration or UV-B irradiation dose insufficiently activate defensive mechanisms, which should neutralize and improve plant resistance to the relatively higher ozone concentration or UV-B irradiation dose. [ABSTRACT FROM AUTHOR]