不同小麦品种对UV-B辐射增强响应的生理特性差异

研究了大田条件下模拟增强UV-B辐射（500 KJ·m^-2,相当于昆明地区臭氧层减少20%）对10个小麦品种生理指标的影响以及小麦对UV B辐射响应的种内差异.结果表明,10个供试小麦品种中有6个品种的叶绿素含量显著下降，叶绿素a降低的程度大于叶绿素b，从而导致叶绿素a/b的比率下降.UV-B对小麦叶片内MDA和类黄酮的影响也具有种内差异,有5个品种的MDA含量显著上升， 2个品种的MDA含量显著下降；4个品种的类黄酮含量显著增加，2个品种的类黄酮含量显著减少.叶绿素和类黄酮含量变化与MDA含量均呈显著负相关关系，类黄酮与小麦UV-B抗性之间存在密切联系.

Intraspecific differences in physiological responses of different wheat cultivars to enhanced UV-B radiation

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.