Trichoderma species show biocontrol potential in dual culture and greenhouse bioassays against Fusarium basal rot of onion
Trichoderma species show biocontrol potential in dual culture and greenhouse bioassays against Fusarium basal rot of onion
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DOI：
10.1016/j.biocontrol.2018.11.007
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发表时间：
2019-03-01
影响因子：
4.2
通讯作者：
Walker, Allison K.
中科院分区：
文献类型：
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作者：
Bunbury-Blanchette, Adele L.;Walker, Allison K.
尖孢镰刀菌（Fusarium oxysporum f.）洋葱疫霉（FOC）在世界范围内影响洋葱生产。尽管目前采取了控制措施（如4年以上轮作和施用杀真菌剂），但新斯科舍省（NS）的发病率仍在上升。这种增长导致每年高达20%的经济损失洋葱生产价值的安纳波利斯山谷，NS。虽然木霉属物种被成功地用作许多作物病原体（包括镰刀菌属）的生物防治剂，以前在新斯科舍省没有针对洋葱的FBR进行过测试。从安纳波利斯山谷的农业土壤中分离到7种木霉菌，并使用ITS rDNA条形码鉴定。利用双培养基生物测定和温室生物测定方法对菌株的生防潜力进行了评价。所有测试的木霉菌种在双重培养中显示出对FOC的拮抗迹象。钩状木霉和T. harzianum最常引起多种拮抗迹象（如菌丝屏障的建立和FOC的过度生长），而T. gamsii最能抑制FOC的生长。土壤接种1000个孢子/克FOC产生约65%的毒性洋葱幼苗; atroviride和T.哈茨氏菌显著降低接种FOC的温室生长洋葱的FBR症状。拮抗FOC的木霉菌株具有开发作为用于新斯科舍省和其他洋葱种植区的生物防治产品的潜力。
Fusarium basal rot (FBR) caused by Fusarium oxysporum f. sp. cepae (FOC) affects onion production worldwide. Despite current control measures, (e.g. 4+ year crop rotations and fungicide application) disease incidence is increasing in Nova Scotia (NS). This increase causes yearly economic losses of up to 20% onion production value in the Annapolis Valley, NS. While Trichoderma species are successfully used as biocontrol agents of many crop pathogens including Fusarium spp., none have previously been tested against FBR of onion in Nova Scotia. Seven Trichoderma species were isolated from agricultural soil of the Annapolis Valley, NS, and identified using ITS rDNA barcoding. Strains were evaluated for biocontrol potential of FOC using dual culture bioassays and greenhouse bioassays on onion. All Trichoderma species tested showed signs of antagonism against FOC in dual culture. Trichoderma hamatum and T. harzianum most frequently elicited multiple signs of antagonism (e.g. creation of a hyphal barrier and overgrowth of FOC), while T. gamsii most inhibited FOC growth. Soil inoculated with 1000 spores per gram FOC produced approximately 65% toxicity in onion seedlings; application of T. atroviride and T. harzianum significantly reduced FBR symptoms in greenhouse grown onions inoculated with FOC. Trichoderma strains antagonistic to FOC have potential for development as biocontrol products for use in Nova Scotia and other onion growing regions.