Combined effects of elevated UV-B radiation and the addition of selenium on common (Fagopyrum esculentum Moench) and tartary [Fagopyrum tataricum (L.) Gaertn.] buckwheat

Plants of Fagopyrum esculentum and Fagopyrum tataricum grown outdoors under three levels of UV-B radiation were studied for 9 weeks, from sowing to ripening. At week 7 they were sprayed with Se solution (1 g/cubic m). Morphological, physiological, and biochemical parameters of the plants were monitored. Elevated UV-B radiation, corresponding to a 17% reduction of the ozone layer, induced synthesis of UV absorbing compounds. In both species it caused a reduction in amounts of chlorophyll a during the time of intensive growth. This effect was increased in tartary buckwheat in the presence of Se. The respiratory potential was lower in plants subjected to enhanced UV-B radiation during the time of intensive growth. The effective quantum yield of photosystem 2 was also reduced in both species and was mitigated by the addition of Se. Se also mitigated the stunting effect of UV-B radiation and the lowering of biomass in common buckwheat