He-Ne激光和紫外-B辐射对红梗牛皮菜黄酮类化合物成分、含量及生长的影响

Effect of He-Ne Laser Radiation on Component,Content of the Flavonoids and Growth Parameters in Beta vulgaris under Enhanced UV-B Radiation

分别用He-Ne激光（5.23mW／mm^2，5min／d）和紫外-B辐射（UV-B，280-320nm）（强度12μW／cm^2，8h／d）及二者复合处理红梗牛皮菜（Beta vulgaris Var．cicida），然后通过水解比色和高效液相色谱（HPLC）法分析叶中甲醇水溶性黄酮类化合物，并测定形态与生长指标。结果表明，UV-B辐射处理后黄酮类化合物含量增加到对照的160％，但激光复合处理后，则恢复到略高于对照的水平。其中槲皮素和黄酮在各处理组中变化非常显著，槲皮素在UV-B（B）、He-Ne激光（L）及二者复合（BL）处理后被大量诱导；而黄酮仅在对照组（CK）和L组出现。分析表明，He-Ne激光与UV-B辐射一样，对黄酮类化合物的诱导是具有选择性的，具有高uV吸收并具较高抗氧化作用的化合物更容易被诱导。因此He-Ne激光很可能通过这种选择机制来减轻UV-B导致的伤害。

Under enhanced UV-B radiation,the effect of He-Ne laser （5.23 mW/mm^2 ,5 min/d） radiation on component, content of the flavonoids and growth parameters in Beta vulgaris var. cicila L. were studied. The content of methanol-soluble flavonoids in leaves were determined by using the method of high performance liquid chromatography （HPLC）. The results showed that the total falvonoids content treated by UV-B radiation （B） were increased to 160% compared with that of control （CK,no UV-B radiation）, while it was only slightly higher in laser and UV-B combined treatment group （BL）. There was no quercetin in leaves of CK, while it was induced substantively by He-Ne laser （L） , UV-B radiation and their combined treatment. Meanwhile ,flavone could be found only in leaves of CK and L group. The results suggested that the induction of UV-B absorb substance by He-Ne laser is selective ,which is similar to that of UV-B radiation. Thus, it is very likely that this selective mechanism is the way by which the He-Ne laser treatment alleviated the damage of UV-B radiation.