[Effect of enhanced UV-B radiation on chemical composition, fungal colonization and decomposition of spring wheat plant].

Under UV-B radiation, the CHO (soluble carbohydrate) concentration in leaves decreased significantly, while the concentrations of HCel (holocellulose) and protein in leaves and that of HCel in stems increased significantly. HCel concentration in roots did not change significantly. Under UV-B radiation, the colonization rates of Penicillium ochro-chloron and Aspergillus niger on leaves and stems increased significantly during growing phase, those of Trichoderma koningii and Aureobasidium pullulans were on the contrary, while that of Aspergillus terreus did not change obviously. After 60 and 100 days of decomposition, the decomposition rates of leaves and stems increased significantly. The decomposition rate of leaves was positively correlated with the concentration of HCel and soluble protein, but negatively with that of CHO. The decomposition rate of stems was also positively correlated with HCel concentration. Under enhanced UV-B radiation, the changes in chemical composition of spring wheat and in fungal colonization rate, and the increase in decomposition rates might resulted in a faster nutrient turnover in wheat field ecosystem and a higher nutrient storage in soil.