Effects of UV-Radiation on Photosynthetic Pigments and UV Absorbing Compounds in Capsicum longum (L.)

The objective of this study was to evaluate the effects of UV radiation on photosynthetic pigments and UV absorbing compounds of pepper plants (Capsicum longum L.) in the greenhouse. Pepper plants were grown in a uniform environment and after 35 days they were exposed to UV-A and UV-C radiation for 15 and 8 days, respectively. Changes in photosynthetic pigments, chlorophyll and carotenoids and UV absorbing compounds, flavonoids and anthocyanins were measured. In this study it was found that the content of Chl-a and Chl-b slightly decreased in UV-R exposed plants and although this reduction was not significant, the total chlorophyll (Chl-T) amount decreased significantly especially in UV-C exposed plants. Carotenoids concentration was also reduced in UV-R exposed plants and this reduction was significant in UV-C exposed plants. UV absorbing compounds were increased. Concentration of flavonoids was significantly increased in both UV-A and UV-C treatments. Although anthocyanin concentration was also increased in UV-R exposed plants, this rise was not significant. UV-C radiation significantly reduced number of leaves per plant, but no significant effect was found on leaf numbers of UV-A treated plants. The fresh weight was significantly decreased in shoot of UV-C treated plants but there was no significant change in fresh weight in UV-A treated plants. In the root of UV-R treated plants no significant changes were observed in fresh weight.