UV-B辐射对滇黄精幼苗生长、抗性生理及代谢物的影响

Effects of UV-B Radiation on the Growth,Resistance Physiology,and Metabolites of Polygonatum kingianum Seedlings

为探究滇黄精幼苗对UV-B辐射的生理响应机制,以两年生药用植物滇黄精为材料,在540 mw/cm^(2)的UV-B辐射强度下,以5 d为一个周期,分别测定处理了0~25 d后的滇黄精幼苗的生物量、抗氧化酶活性、MDA、类黄酮的含量.结果表明:在UV-B辐射下,滇黄精幼苗的株高与叶绿素含量呈下降趋势,并随着辐射时间延长,影响效果更明显,UV-B辐射对POD、SOD活性的影响呈升高趋势,在UV-B辐射中期,相较于CK显著升高.对MDA含量的影响呈现先升高后降低的趋势.滇黄精叶片中类胡萝卜素含量及叶片和块茎中类黄酮含量也随着辐射时间的延长而增加.因此,UV-B辐射处理可抑制滇黄精幼苗的生长,使其抗氧化酶活性以及类黄酮含量显著增加,从而增强滇黄精对UV-B辐射的抗性,对植株起到保护作用.

In order to investigate the physiological response mechanism of Polygonatum kingianum seedlings to UV-B radiation,the biomass,antioxidant enzyme activity,MDA and flavonoid contents of P.kingianum seedlings were measured after 0 to 25 days of treatment under the UV-B radiation intensity of 540 mw/cm^(2) every 5 days.The results show that under UV-B radiation,the plant height and chlorophyll content of P.kingianum seedlings show a downward trend,and with the extension of radiation time,the effect is more obvious.The effect of UV-B radiation on POD and SOD activity shows an increasing trend,while in the middle of UV-B radiation,compared with CK,it increases significantly.The effect on MDA content shows a trend of increasing first and then decreasing.The carotenoid content in leaves and flavonoid content in leaves and tubers increase with the extention of UV-B radiation time.In conclusion,UV-B radiation treatment could inhibit the growth of P.kingianum seedlings,increase an⁃tioxidant enzyme activity and flavonoid content,and enhance the resistance of P.kingianum to UV-B radiation.