欧美杨溃疡病防治的初步研究

为探索防治欧美杨溃疡病的方法，采用平板稀释法，从欧美杨溃疡病病株的根际土壤中分离出86株细菌菌株。经平板对峙培养，得到5株对欧美杨溃疡病原菌(Lonsdalea quercina)有拮抗作用的菌株。室内离体枝条试验和田间杨树防治试验结果表明，以菌株P2和P4的防效较好，通过浇根处理，室外防效分别达到51.8%和48.6%。经鉴定菌株P2和P4分别为枯草芽孢杆菌Bacillus subtilis和委内瑞拉链霉菌Streptomyces venezuelae。用中生菌素、农用链霉素、新植霉素、多抗霉素等4种抗生素类药剂和45%代森铵水剂、80%乙蒜素乳油杀菌剂在室内做抑菌试验，中生菌素、新植霉素对病原菌无明显的抑制效果，其他4种有一定的抑制作用。其中农用链霉素100倍稀释液的防效较好，经浇根处理，室外防效达38.2%。试验为欧美杨溃疡病的防治提出了初步的方法。

Primary Study for Control of Lonsdalea Canker of Poplar

To explore the method for the control of Lonsdalea canker of poplar, based on the plate dilution method, 86 bacterial strains were isolated from rhizosphere soil of trees with Lonsdalea canker of poplar. Dual culture experiments results showed that 5 bacterial strains were of antibacterial activities against the pathogen Lonsdalea quercina. Control experiments with cutting indoor and trees in the field indicated that strains P2 and P4 were more effective than the other 3 strains, and control effectiveness in field can reach to 51.8% and 48.6% respectively. Strain P2 was identified as Bacillus subtilis, and the strain P4 was Streptomyces venezuelae. Four kinds of antibiotics and 2 kinds of fungicides were used to test inhibition effectiveness against the pathogen with dual culture experiments. Zhongshengmycin and Xinzhi had no obvious antibacterial effectiveness against the pathogen whereas polyoxin, streptomycin, ethylicin and amobam had. 100-fold dilution of agricultural streptomycin had better control effectiveness, prevention rate can reach to 38.2%. The experiments provided primary an approach for control of Lonsdalea canker of poplar.