论文部分内容阅读
以沈阳市2个主要树种白桦(Betula platyphylla)、银中杨(Populus alba×P.berolinensi)1年生植株为对象,利用开顶箱(OTCs)模拟法,研究了高浓度O3(约160 nmol·mol-1)对2树种叶片光合作用的影响。结果表明:与对照相比,高浓度O3熏蒸的植株叶片出现坏死斑等伤害症状,熏蒸14和30 d时,白桦单叶伤害面积分别为72.0%和91.6%,显著高于银中杨的21.5%和26.2%(P<0.01)。白桦叶片Chl-a和Car含量显著降低,银中杨的Chl-b含量显著上升(P<0.05)。2树种叶片的离子渗漏率和丙二醛(MDA)含量均显著增加(P<0.05),超氧化物歧化酶(SOD)和抗坏血酸过氧化物酶(APX)活性均显著降低(P<0.05)。高浓度O3导致2树种净光合速率(Pn)下降,胞间CO2浓度(Ci)上升,但银中杨气孔导度(Gs)增加,而白桦的降低。推断O3导致2树种光合作用降低是由非气孔因素限制引起,高浓度O3熏蒸下银中杨耐性较白桦强,白桦可以作O3的指示树种。
In order to study the effects of high concentrations of O3 (about 160 nmol · L -1) on the annual plants of Betula platyphylla and Populus alba × P.berolinensi in Shenyang city, mol-1) on the photosynthesis of two tree species. The results showed that compared with the control, the leaves of fumigated plants exposed to high concentrations of O3 showed necrotic lesions and other injuries. When fumigated for 14 and 30 days, the single leaf injury area of Betula platyphylla was 72.0% and 91.6%, respectively, significantly higher than that of 21.5 % And 26.2% (P <0.01). The content of Chl-a and Carr of the leaves of Betula platyphylla decreased significantly, while the content of Chl-b of C. poplar increased significantly (P <0.05). (P <0.05) and the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) were significantly decreased (P <0.05) ). High concentrations of O3 led to a decrease in net photosynthetic rate (Pn) and intercellular CO2 concentration (Ci) in two species, but increased stomatal conductance (Gs) in the mid-poplar and decreased in the birch. It is inferred that the decrease of photosynthesis caused by O3 is caused by the non-stomatal limitation. The high tolerance of O3 in O3 is stronger than that in Betula platyphylla, and Betula platyphylla can be the indicator species of O3.