不同小麦品种对UV-B辐射增强响应的生理特性差异

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(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.

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 ） eultivars 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 culrivars 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.