中文摘要：

测定了对青杨脊虎天牛具有不同抗性的杨树，包括小青杨、小叶杨、小青×黑杨、大青杨、小黑杨、中东杨、白城二号杨、斯大林杨、俄罗斯杨、银中杨韧皮部中的苯丙氨酸解氨酶（PAL）、多酚氧化酶（PPO）、过氧化氢酶（CAT）、过氧化物酶（POD）以及超氧化物歧化酶（SOD）的活性。结果表明：抗虫树种中苯丙氨酸解氨酶、多酚氧化酶、过氧化物酶的活性普遍高于感虫树种，过氧化氢酶和超氧化物歧化酶的活性无明显规律。

英文摘要：

An experiment was conducted to determine the enzyme activities of PAL, PPO, CAT, POD and SOD in the phloem of ten poplar species, Populus pseudo-simonii, P. simonii, P. pseudo-simonii × P. nigra, P. ussuriensis, P. simonff × P. nigra, P. berolinensis , P. ＇ bailin-2 ＇ , P. stalinetz, P. russkii , P. alba × P. berolinensis , in order to study their resistance ability to Xy-lotrechus rusticus. Result shows that the activities of PAL, PPO and POD are higher in the poplar species with high resistance ability compared with those without resistance, and the activities of CAT and SOD have no obvious regularity.