枸杞根腐致病菌及拮抗菌的分离鉴定

旨在探索枸杞根腐病发生地根际土壤生防细菌资源，为该病的防治提供理论依据。采用组织分离法分离枸杞根腐致病菌，对其进行形态学、分子生物学鉴定和柯赫氏法则验证；再利用平板对峙法，以分离出的病原菌为靶标，筛选具有拮抗效果的菌株，对其进行鉴定。结果表明：从青海省海西蒙古族藏族自治州主要栽培枸杞林中分离鉴定出4种致病菌，分别为黄色镰刀菌（Fusarium culmorum）、三线镰刀菌（F.tricinctum）、尖孢镰刀菌（F.oxysporum）、木贼镰刀菌（F.equiseti）；经筛选，有8株生防细菌对4种病原菌具有不同程度的拮抗效果，其中，抑菌效果最好的是QH-588菌株，其抑制率在36.09%~51.79%；经形态学和16S rDNA/Gyr B基因分析鉴定，其中1株为萎缩芽孢杆菌（Bacillus atrophaeus），5株为枯草芽孢杆菌（B.subtilis），2株为短小芽孢杆菌（B.pumilus）。在国内首次报道了三线镰刀菌为枸杞根腐病病原菌，筛选出的生防细菌在室内对枸杞根腐病的4种病原均具有较好的拮抗效果，可作为防治青海省枸杞根腐病的候选菌株。

Isolation and Identification of Pathogenic Fungi and Antagonistic Bacteria from Lycium barbarumRoot Rot

Lycium barbarum root rot is aserious disease in wolfberry cultivation.Exploring biocontrol bacterial resources in the rhizosphere soil canaid in its control.Using tissue isolation method,we isolated the pathogenic bacteria of L.barbarum root rot, and confirmed it through morphology, molecular biology identification, and Koch postulates; we screened the strains with antagonistic effectson the isolated pathogenic bacteria using plate confrontation method, with isolated pathogenic bacteriatoas target.Four pathogenic bacteria,Fusarium culmorum, F.tricinctum, F.oxysporum, and F.equiseti were isolated and identified from the main cultivar of L.barbarum forest in Haixi Mongol and Tibetan Autonomous Prefecture of Qinghai province;the plate confrontation test showed that eight biocontrol bacteria strains had varying degrees of antagonism effect on 4 pathogenic fungi, with QH-588 strain exhibiting the best bacteriostatic effect(inhibition rate of 36.09%-51.79%); after morphological and 16S rDNA/GyrB gene analysis, we identified one strain as Bacillus atrophaeus,five strains as B.subtilis, and two strains as B.pumilus. The identified three-line F.tricinctum is the first reported wolfberry root rot pathogen in China, and the selected biocontrol bacteria have a good antagonistic effect on the four pathogens of wolfberry root rot indoors, providing candidate strains for the prevention and control of L.barbarum root rot in Qinghai province.