A study has been done in order to evaluate the ill effects of UV-A,UV-B and UV-C on pigmentation and malondialdehyde content of floating macrophytes (Lemna sp., Pistia sp. and Eichhornia sp.) in one, three, and five days interval. Study results revealed that all types of ultraviolet light (UV-A, UV-B, and UV-C) did not produce same extent of ill effects on the studied macrophytes. Pistia sp. and Eichhornia sp. showed similar reduction pattern of chl a/chl b ratio with respect to control. Results also suggest that among the three types of radiation only UV-B showed higher level of changes in both the pigment and malondialdehyde content. Moreover, among the three tested macrophytes only Lemna sp. showed some protective role against UV radiation compared to other to macrophytes
