Abstract: Influences of enhanced ultraviolet radiation (UV-B,280~315 nm) on biomass accumulation of spring wheat colonies were investigated and assessed under field conditions. UV-B radiation resulted in decrease of biomass accumulation of leaves, stems, roots, spikes and whole plant, changes in the patterns of biomass partitioning, and reductions in grain yield. With 5.31 kJ/m² UV-B radiation, HI decreased significantly. Model analyses indicated that UV-B radiation could decrease the accumulation rates of total biomass. The total biomass and aboveground biomass reduced with the increase of UV-B radiation. Predictor models show that enhanced UV-B radiation resulting from 10% and 20% depletion of global ozone have had great influence on the decrease of grain yield and boimass of leaves and spikes, and did not have great influence on the reduction of root biomass.

Key words: UV-B radiation, spring wheat colonies, biomass, yield