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以4年生黄檗(Phellodendron amurense Rupr.)幼苗为实验材料,利用开顶箱模拟法,开展了4个不同浓度O340(对照)、80、120和200 nmol·mol-1的气体熏蒸实验,测定并分析了黄檗叶片光合色素含量、净光合速率、膜脂质过氧化产物和抗氧化酶活性等生理指标的变化规律。结果表明:与CK相比,随着O3浓度增加和处理时间延长,黄檗幼苗叶片叶绿素总含量、类胡萝卜素含量和净光合速率显著下降(P<0.05),最大降幅分别为52.76%、44.57%和54.67%;叶片离子渗漏率、丙二醛含量显著增加(P<0.05),最大增幅分别为101.49%和70.21%。当O3浓度为80 nmol·mol-1时,叶片最大光化学效率(Fv/Fm)无显著变化,而O3浓度为120和200 nmol·mol-1时,Fv/Fm显著下降(P<0.05),表明黄檗幼苗的光合系统功能在超高浓度臭氧下受到了显著伤害。叶片抗氧化超氧化物歧化酶活性在开始处理后的前14 d升高,随后下降,最大降幅为17.22%。O3浓度为120和200nmol·mol-1时,超氧阴离子(O2-·)含量显著升高(P<0.05);O3浓度为80 nmol·mol-1时,O2-·含量在处理7 d与CK相比显著增加,随后无显著差异。表明黄檗幼苗在生长初期对中等高浓度(80 nmol·mol-1)臭氧熏蒸具有一定的适应和耐受性是因其具有较强抗氧化保护能力,更高浓度的O3或更长时间的熏蒸对叶片光合系统产生破坏。
Four-year-old Phellodendron amurense Rupr. Seedlings were used as experimental materials. Four open-chamber simulation methods were used to test the gas fumigation at different concentrations of O340 (control), 80, 120 and 200 nmol · mol-1 The changes of photosynthetic pigment content, net photosynthetic rate, membrane lipid peroxidation products and antioxidant enzyme activities in leaves of P. barbae were analyzed. The results showed that the total chlorophyll content, carotenoid content and net photosynthetic rate were significantly decreased (P <0.05) with the increase of O3 concentration and treatment time compared with CK (P <0.05), with the maximum decrease of 52.76% and 44.57% And 54.67% respectively. Leaf ion leakage rate and malondialdehyde content increased significantly (P <0.05) with the maximum increase being 101.49% and 70.21% respectively. When the concentration of O3 was 80 nmol · mol-1, the maximum photochemical efficiency (Fv / Fm) of leaves was not significantly changed, while the Fv / Fm was significantly decreased at O3 concentrations of 120 and 200 nmol · mol- The results showed that the function of photosynthetic system of barberry seedlings was significantly damaged under ultra-high concentration of ozone. The antioxidant activity of superoxide dismutase (SOD) increased in the first 14 days after the start of treatment, and then decreased with the maximum decrease of 17.22%. The content of O2- · was significantly increased at O3 concentration of 120 and 200 nmol · mol-1 (P <0.05). When O3 concentration was 80 nmol · mol-1, CK increased significantly, then no significant difference. The results showed that the seedlings of P. cercbana could adapt and tolerate medium-high concentration (80 nmol · mol-1) ozone fumigation at early growth stage because of its strong anti-oxidative protection, higher concentration of O3 or longer fumigation Damage to leaf photosynthetic system.