Intraspecific differences in physiological responses of different wheat cultivars to enhanced UV-B radiation
研究了大田条件下模拟增强UV-B辐射（500 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UVB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.
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·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 antiUV-B radiation of wheat.
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