芦荟黑斑病发生规律及室内药剂筛选

Occurrence Regulation of Alternaria obpyriformis T.Y Zhang and Fungicide Screen in Lab

为了解芦荟黑斑病的发生规律,进一步为防治提供理论依据。该文对三种越冬形式的病原菌分别采用直接镜检、组织分离法及致病性测定对芦荟黑斑病菌(Alternaria obpyriformis T.Y.Zhang)进行了越冬场所和越冬方式的研究。通过针刺法、涂抹法及玻片粘着法确定病菌侵入和传播途径。人工接种条件下测定了病菌对5科10种植物的侵染能力。采用孢子萌发法和菌丝生长速率法对病菌进行室内药剂筛选。结果表明,病原菌可在病残体上以菌丝和分生孢子越冬,通过气孔和伤口侵入寄主,分生孢子能借助气流传播;人工接种时能侵染豆科、十字花科的部分植物。供试的7种药剂对病菌菌丝生长和孢子萌发都有显著的抑制作用,其中施保功可湿性粉剂对其病菌的菌丝体抑制效果最好,抑菌率达84.24%;扑海因悬浮剂对分生孢子萌发抑制效果最佳,抑制率为67.44%。

In order to explain the occurrence regulation of Alternaria obpyriformis T.Y Zhang and be useful for the disease control, the direct-checking method, tissue isolation method and pathogenicity detection were used to study the overwinterring place and overwinterring way of Alternaria obpyriformis T. Y Zhang. The needle puncture, leaf brushing and slide attachment were used to determine the invasion and spreading ways. We detced the infection ability of Alternaria obpyriformis T.Y Zhang on 10 plant under the condation of artificial inoculation. Fungicide screen assays in lab were performed by detecting the spore germination and the mycelium growth rate. The results showed that A lternaria obpyriformis T.Y Zhang could live through the winter on plant debris with the mycelium and the pycnidiospore. The pathogen could invade host by air hole and wound. The pycnidiospore could spread through airflow. Alternaria obpyriformis could infect some leguminous plants and crucifer by artificial inoculation. Seven fungicides could obviously inhibit the mycelium growth and spore germination of Alternaria obpyriformis T.Y Zhang, while prochloraz proved to be the most effective fungicide with the inhibition rate of 84.24% and followed by those of iprodone with the inhibition rate of 67.44%