柱枝孢叶斑病侵染对牡丹生理特性的影响

Effects of Infection by Cylindrocladium canadense on Physiological Characteristics of Tree Peony

以牡丹‘藏枝红’为试材,研究了柱枝孢叶斑病(Cylindrocladium canadense)侵染对牡丹生理特性的影响。结果表明:病原菌侵染后牡丹叶片净光合速率(Pn)和光合色素含量显著降低,同时表观量子效率和羧化效率均显著下降,表明侵染增强了牡丹叶片的光抑制;C.canadense侵染后,抗氧化酶活性发生显著变化,超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性在侵染5d先略有升高,然后呈显著下降趋势;过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)活性一直呈下降趋势;O·2产生速率和H2O2积累量明显增加,丙二醛(MDA)含量显著升高。C.canadense侵染使抗氧化酶活性有不同程度的下降,导致活性氧(ROS)含量增加,对生物膜系统造成伤害,从而降低了牡丹叶片的光合能力。

Taking tree peony ＇Zangzhihong~ as material, the effect of infection by Cylindrocladium canadense on physiological characteristics of leaves were estimated. The results showed that,the net photosynthetic rate （Pn） and the photosynthetic pigments decreased significantly after infection. In the same time, the apparent quantum yield and carboxylation efficiency of tree peony leaves both decreased greatly after infection. This indicated that the infection of C. canadense enhanced the photoinhibition. Antioxidant enzymes activity changed greatly in infected tree peony leaves. The activity of SOD and CAT increased slightly in 5 d after infection, but had declined significantly from then. That of POD and APX had been decreased greatly after infection. In the same time, the content of MDA increased and was in agreement with the accumulation of ROS. All of this showed that infection of C. canadense led to decline of antioxidant enzymes activity in different degrees and resulted in the accumulation of ROS,damaging the membrane system of cell and thus reduced the photosynthetic capacity of tree peony leaves.