银杏根腐病病原菌分离及防治药剂筛选

The pathogen separation and screening fungicides of root rot of Ginkgo biloba

为了有效防治银杏根腐病,以取自石家庄槐安西路、唐山建设路、保定长城北大街、河北农业大学校内的银杏根系为试材,采用组织分离法对其病健组织的病原菌进行分离及形态鉴定;在室内条件下,采用菌丝生长速率法研究比较5种杀菌剂对病原菌的毒力作用;并将筛选出来的药剂做田间防效试验。结果表明:该试验共获得2个具有致病性的菌株SJZ-4、SJZ-5,这2个菌株均为尖孢镰刀菌(Fusarium oxysporum);室内筛选出了3种抑菌效果较好的药剂,即枯草芽孢杆菌、30%苯醚甲环唑、80%多菌灵;稀释300倍的枯草芽孢杆菌田间防治效果最好,可使62.5%的银杏夏季不焦叶或者仅轻微焦叶,严重焦叶(焦叶量>70%)的发生程度仅为6.25%。

In order to effectively control the root rot of Ginkgo biloba, using the root of G. biloba as the experimental mate- rials, which was from Huaian West Road in ShiJiazhuang, Jianshe road in Tangshan, Changcheng North street of Baoding and Agricultural University of Hebei, we isolated the pathogen by using the method of tissue isolation and identified the morphological characteristics, and studied the effects of 5 fungicides to root rot of G. biloba with mycelia growth rate in- doors then used this screened fungicides in field experiment. The results showed that two isolates named SJZ-4, SJZ-5 were obtained from the root of G. biloba. Pathogenic test indicated that the 2 separate matter so possessed pathogenic. The pathogen of the root of G. biloba was identified as Fusarium oxysporum. Bacillus subtilis, difenoconazole 30%, carbenda- zim 80% showed better effect to control the root rot of G. biloba. B. subtilis diluted 300 times with pure water worked effectively, making 62.5% G. biloba without yellow leaves or only having a little, the proportion of severe yellow leaves is only 6.25 %.