铜胁迫下链格孢菌对白车轴草生理生态的影响

通过盆栽实验研究了Cu胁迫下接种病原菌链格孢菌(Alternaria tenuis Nees)对白车轴草(Trifolium repens L.)生理生态指标的影响.结果表明:在未接种的对照组中,随着Cu浓度的增大(0~3000mg.kg-1),植株叶片失绿,生物量下降,叶绿素a、b、a b和类胡萝卜素及叶片可溶性蛋白质含量下降;植物体内丙二醛(MDA)高度积累,细胞膜结构遭到损坏,电导率增大;植株活性氧清除系统受损,不能保持原有平衡,超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性显著降低,过氧化物酶(POD)活性升高.接种链格孢菌后,植株叶片色素、膜系统及保护酶系统的损伤均加重,与不接种对照组相比,相同浓度Cu处理的叶绿素a、b、a b和类胡萝卜素、可溶性蛋白质含量、SOD和CAT活性均呈不同程度的下降,而电导率、MDA含量和POD活性则有所上升.

Effects of Alternaria tenuis Nees on Trifolium repens L. Under Cu stress

With pot culture, this paper studied the effects of Alternaria tenuis Nees inoculation on the eco-physiological indices of Trifolium repens L. leaf under Cu stress. The results showed that in the control (not inoculated with the pathogen), the contents of photosynthetic pigments (chlorophyll a, b, a + b and carotenoid) and soluble protein in T. repens leaves decreased markedly with increasing Cu concentration (0-3000 mg x kg(-1)). The enhancement of cellular membrane lipids peroxidation with the increase of Cu concentration led to a rapid accumulation of malondialdehyde (MDA), the damage on cellular membrane structure, and an increase of electric conductivity. The balance of active oxygen metabolism systems was broken, SOD and CAT activities decreased, while POD activity increased. After inoculation with A. tenuis, the damages of Cu on plant membrane systems and active oxygen metabolism systems aggravated, the contents of photosynthetic pigments and soluble protein and the activities of SOD and CAT decreased to different degree, while the electric conductivity, MDA content and POD activity increased markedly, compared with the control.