Effect of enhanced UV-B radiation on biomass, net photosynthesis and pigments in four tropical legumes

Abstract

Experiments were conducted under field conditions to assess the responses of four tropical leguminous plants (Vigna radiata L. (Wilczek) cv. PS-16, Phasedus mungo L. (Hepper) cv. Pant U-30, Gylcine max L. (Merr.) cv. Punjab 1 and Phaseolus mungo L. (Hepper) cv. Mash-48), to enhanced UV-B radiation. Ultraviolet-B radiation was supplied by 313 Q-panel UV-B lamps and corresponded to 15% O3 depletion at 25°N latitude. Ultraviolet-B radiation affected both photosynthesis and stomatal resistance of all four plants. Biomass decreased significantly due to UV-B exposure. Chlorophyll and flavonoids also declined due to UV-B exposure. Thus these tropical legumes were markedly sensitive to enhanced UV-B radiation.