The response of photosynthesis and growth of spring wheat to enhanced UVB radiation and soil drought

The response pigments contents, photosynthesis, biomass and yield of spring wheat cultivars Dingxi24（Triticum aestivum cv. Dingxi24）to enhanced UVB radiation and soil drought under the field condition of pot cultivation. The radiation or drought, simply or combined, led to the decrease in foliar flavnoid content, but only there is statistically significant under the condition of the combination. The water stress caused the reduction of chlorophyll b, but not the content of chlorophyll a and carotenoids. UVB radiation and the combination all led to significantly the reduction of photosynthetic pigments. Various treatments could inhibit the photosynthesis, and the ordination is controlcombination droughtUVB. The drought played more obvious roles in stomatal resistance. There was higher internal carbon dioxide concentration under the condition of drought and the combination, and lower internal CO2 under the condition of UVB radiation. At harvest, the total biomass were significantly declined comparison to control, the order from high to low was controlcombinationUVBdrought. The composition of spikes and yield were also negatively impacted。The results showed that there were interactive between UVB radiation and soil drought, suggesting that one stress factor might alleviate the inhibitory effect of another stress on spring wheat.