对经过11. 8 μW·cm^-2 UV-B 连续辐照7 d 后黄芩(Scutellaria baicalensis Georgi)幼苗的生长及一些生理生化指标进行了测定和分析。结果表明:经11. 8 μW·cm^-2 UV-B 辐照7 d 后,黄芩幼苗的平均株高和单株平均干质量分别为8. 1 cm 和0. 026 g,与对照无显著差异(P>0. 05);叶片的叶绿素a、叶绿素b、总叶绿素及类胡萝卜素含量分别为2. 89、1. 04、3. 93 和0. 48 mg·g^-1 ,均极显著低于对照(P<0. 01);叶绿素a/ b 比值以及类胡萝卜素/ 总叶绿素比值分别为2. 78 和0. 122, 分别显著或极显著高于对照(P<0. 05,P<0. 01); 叶片中的CAT 和POD 活性均极显著高于对照(P<0. 01),分别为2 412 和2 208 U·g^-1 ;SOD 活性(1 228 U·g^-1 ·h^-1 )较对照略有升高,但差异不显著(P>0. 05);叶片中的抗坏血酸(ASA)及游离脯氨酸含量均显著高于对照(P<0. 05),分别为11. 5 mg·g^-1 和57. 7

μg·g^-1 ;MDA 含量高于对照,紫外吸收物相对含量和苯丙氨酸解氨酶(PAL)活性均低于对照,但差异不显著(P>0. 05)。研究结果显示,11. 8 μW·cm^-2 UV-B 连续辐照7 d 对黄芩幼苗的生长无显著抑制作用,黄芩幼苗能够通过自身的抗氧化系统有效减轻UV-B 辐射产生的氧化损伤,对UV-B 辐射表现出一定的耐受能力。

The growth indexes and some physiological-biochemical indexes of Scutellaria baicalensis Georgi seedlings radiated continuously for 7 d with 11. 8 μW · cm^-2 UV-B were determined and analyzed. The results show that after radiated with 11. 8 μW·cm-2 UV-B for 7 d, average height and dry weight of individual of S. baicalensis seedlings are 8. 1 cm and 0. 026 g, respectively, and have no significant difference with the control (P>0. 05). The contents of chlorophyll a(Chla), chlorophyll b (Chlb), total chlorophyll (Chl) and carotenoid (Car) in leaves are 2. 89, 1. 04, 3. 93 and 0. 48 mg·g^-1, respectively, and those all are extremely significantly lower than those of the control (P<0. 01). While ratios of Chla/ Chlb and Car/ Chl are 2. 78 and 0. 122, respectively, which are significantly and extremely significantly higher than those of the control ( P < 0. 05, P < 0. 01), respectively. CAT and POD activities in leaves are extremely significantly higher than those of the control (P<0. 01) and reach 2 412 and 2 208 U·g^-1, respectively, and SOD activity (1 228 U·g^-1·h^-1) in leaves enhances slightly comparing with the control but the difference is not significant (P >0. 05).Contents of ascorbic acid (ASA) and free proline in leaves are significantly higher than those of the control (P<0. 05), with the value of 11. 5 mg·g^-1 and 57. 7 μg·g^-1, respectively. MDA content is higher while UV-absorbing compound relative content and phenylalanine ammonia-lyase (PAL) activityare lower than those of the control, but the differences are all not significant (P>0. 05). It is suggestedthat the continuous radiation for 7 d with 11. 8 μW·cm^-2 UV-B has no obvious inhibition to the growth of S. baicalensis seedlings, and the oxidative damages caused by UV-B radiation can effectively reduce by means of own antioxidant system. Thus, S. baicalensis seedling exhibits a certain tolerance ability to UV-B radiation.