Impact of UV radiation and selenium on two buckwheat species

Abstract

The impact of selenium (Se) addition and UV radiation on Tartary buckwheat and hybrid buckwheat were studied. Both buckwheat species grew outdoors at the experimental field of the Biotechnical Faculty in Ljubljana. They were exposed to four different treatments regarding the UV radiation (ambient or reduced) and added Se (naturally accessible or foliary treated with Na selenate in concentration 10 mg Se L-1). The content of pigments (chlorophyll a and b, carotenoids, anthocyanins) and UV absorbing compounds, transpiration rate, photochemical efficiency of photosystem II (PS) II and respiratory potential were measured. At the end of experiment we determined the biomass of different plant parts. The results showed that irrespective of the buckwheat species the added Se lowered the content of chlorophyll a and carotenoids, while it increased the effective quantum yield of PS II and transpiration rate. UV radiation reduced the content of anthocyanins only. Se and UV-B radiation as independent factors exerted no impact on buckwheat yield. Hybrid buckwheat had a higher physiological activity than the Tartary buckwheat yet a smaller biomass of plant parts, including reduced yield. Ambient UV radiation had a slightly negative impact on hybrid buckwheat while it had no noticeable negative impact on Tartary buckwheat. The Se treated Tartary and hybrid buckwheat were suitable for human andanimal diet regarding to Se concentrations in leaves and grains.