Intraspecific differences in physiological responses of different wheat cultivars to enhanced UV-B radiation
不同小麦品种对UV-B辐射增强响应的生理特性差异

In this paper, field studies were conducted to determine the potential of alterations in physiology, and the intraspecific differences in sensitivity of 10 wheat (Triticum aestivum) cultivars to enhanced UV-B radiation. The supplemental UV-B radiation was 5.00 kJ x m(-2), simulating a depletion of 20% stratospheric ozone in Kunming area. The results showed that six of 10 tested wheat cultivars showed significant changes in total chlorophyll content, among which, chlorophyll a was strongly reduced, but chlorophyll b was reduced to a lesser extent, leading to a decrease in chlorophyll a/b ratio. The effects of UV-B on MDA and flavonoid contents also showed intraspecific difference. The MDA content of 5 cultivars was significant increased, while that of 2 cultivars was decreased. Four cultivars had significantly increased flavonoid content, but the flavonoid content in 2 cultivars was significantly decreased. The changes of chlorophyll and flavonoid contents were significantly correlated with the content of MDA(r = -0.78, P < 0.01 and r = -0.75, P < 0.05 respectively). There was a correlation between flavonoid and anti-UV-B radiation of wheat.