假单胞菌属S10B9菌株对紫花苜蓿镰刀菌根腐病的生防作用

Boicontrol effect of Pseudomonas S10B9 onFusarium root rot of alfalfa

摘要:

【目的】 获得对紫花苜蓿镰刀菌根腐病具有防效的生防菌株。【方法】 对分离自紫花苜蓿根际土壤、对苜蓿镰刀菌根腐病菌有拮抗能力的菌株S10B9 进行生理生化鉴定及16S rDNA 测序鉴定，并通过抑菌性试验及盆栽试验评价菌株S10B9 对镰刀菌的抑制能力及对紫花苜蓿镰刀菌根腐病的盆栽防效。【结果】 菌株S10B9 经鉴定为假单胞菌属（Pseudomonas spp.）。菌株S10B9 对尖孢镰刀菌（Fu-sarium oxysporum）、腐皮镰刀菌（F. solani）、轮枝镰刀菌（F. verticillioides）、层出镰刀菌（F. prolifera-tum）的菌丝生长均有抑制作用，其抑菌率分别为57. 44%、53. 68%、59. 60%、57. 00%。菌株S10B9 无菌发酵液对尖孢镰刀菌、腐皮镰刀菌、轮枝镰刀菌、层出镰刀菌孢子萌发均具有抑制活性，抑制率分别为77. 17%、48. 79%、78. 95%、76. 01%。培养36、96 h 的菌株S10B9 无菌发酵液均能抑制4 种镰刀菌菌丝生长。菌株S10B9 能够降低腐皮镰刀菌引起的紫花苜蓿根腐病发病率，不影响紫花苜蓿正常生长，其盆栽防效为39. 48%。【结论】 菌株S10B9 对尖孢镰刀菌、腐皮镰刀菌、轮枝镰刀菌、层出镰刀菌均有抑制作用，对紫花苜蓿镰刀菌根腐病具有良好盆栽防效。

Abstract:

【Objective】 To identify biocontrol strains effective against alfalfa Fusarium root rot.【Method】 Inthis research，strain S10B9 was isolated from the rhizosphere soil of alfalfa and the genus was identified by physiologicaland biochemical characteristics，as well as 16S rDNA sequencing analysis. The inhibitory ability of strain S10B9against Fusarium and its effectiveness in controlling Fusarium root rot in alfalfa were evaluated through bacteriostatictest and pot experiment.【Result】 Strain S10B9 was identified as Pseudomonas spp. Strain S10B9 exhibited inhibitoryeffects against F. oxysporum，F. solani，F. verticillioides and F. proliferatum，with antibacterial rates of 57. 44%，53. 68%，59. 60% and 57. 00%，respectively，as observed in the plate confrontation test. The sterile fermentationbroth of strain S10B9 also inhibited spore germination of these Fusarium strains，with inhibition rates of77. 17%，48. 79%，78. 95% and 76. 01%，respectively. Furthermore，the sterile fermentation broth of strain S10B9，with culture times of 36 h and 96 h，inhibited the growth of all four Fusarium strains. In the pot experiment，thestrainS10B9 reduced the incidence rate of alfalfa root rot caused by F. solani by 39. 48% without affecting the normalgrowth of alfalfa. 【Conclusion】 Strain S10B9，identified as Pseudomonas spp. ，demonstrated inhibitory effectsagainst F. oxysporum，F. solani，F. verticillioides and F. proliferatum，and exhibited effective prevention of alfalfa Fusariumroot rot.