Search

Changes in the content of pigments and rate of photosynthesis in Azolla microphyllaKaulf. fronds were measured during growth under solar and ultraviolet-C (UV-C) supplemented solar radiation. Maximum content of total chlorophyll (Chl) was observed on the 13thday (termination of the experiment) of treatment in both control and treated plants. The treated plants had significantly lower total Chl and carotenoid contents than the control plants during the 1stday of growth. After the 4thday of exposure to UV-C supplemented solar radiation, the Chl and carotenoids accumulation increased in treated plants, so that the pigment concentration in the treated fronds was nearer to the control values after the 13thday of treatment. Significant increase in UV absorbing pigments, anthocyanins, and flavonoids was observed at the 13thday of treatment. In spite of the roughly similar photosynthetic pigment concentration, the photosynthetic activity measured as the rate of electron transport at photosystem 2 was only 65 % of the control values after 13 d of UV-C exposure.