摘要
【目的】分离鉴定高粱茎腐病的病原,并测定高效广谱贝莱斯芽孢杆菌(Bacillus velezensis)菌株的抑菌效果,为高粱镰刀茎腐病的绿色防控提供参考。【方法】采用病健组织分离法分离高粱幼苗茎腐病菌并通过科赫法则验证;利用形态特征结合多基因联合的分子系统发育分析对病原进行鉴定;通过拮抗实验和无细胞上清液平板抑菌实验,评价贝莱斯芽孢杆菌SB023菌株对高粱镰刀茎腐病菌的抑菌效果。【结果】从盆栽发病的高粱幼苗上分离到6株真菌,根据形态学特征和ITS、TEF-1α、CAM及RPB2的序列分析,将其鉴定为产黄色镰刀菌(Fusarium thapsinum)和尖孢镰刀菌(F.oxysporum),选取代表菌株进一步通过科赫法则验证,确定这2种镰刀菌均为高粱茎腐病的病原。拮抗实验结果表明,贝莱斯芽孢杆菌SB023对产黄色镰刀菌GL002YB2-4和尖孢镰刀菌GL002NC3-1均有显著的拮抗效果,抑制率分别为42.89%和58.52%。SB023发酵液的无细胞上清液抑菌实验结果显示,SB023发酵液对产黄色镰刀菌GL002YB2-4和尖孢镰刀菌GL002NC3-1的气生菌丝生长抑制显著;镜检显示随着添加SB023发酵液量的增加,PDA平板的产黄色镰刀菌或尖孢镰刀菌的菌丝中出现原生质体聚集和菌丝泡状化膨大,说明贝莱斯芽孢杆菌发酵液中存在诱导真菌菌丝畸变的活性物质。【结论】明确了2种高粱镰刀茎腐病的病原,其中尖孢镰刀菌为首次报道,并评价贝莱斯芽孢杆菌对2种病原的抑菌活性,为高粱镰刀茎腐病的绿色防控提供参考。
【Objective】The purpose of this study was to isolate and identify the pathogens of sorghum stalk rot,and to test the inhibitory effect of the high-efficient and broad-spectrum strains of Bacillus velezensis against the pathogens,so as to provide a reference for the green prevention and control of Fusarium stalk rot in sorghum.【Method】The pathogens were isolated by separation of diseased-healthy tissues from sorghum seedlings and verified by Koch's rule.The pathogens were identified by morphological characteristics combined with molecular phylogenetic analysis based on multiple gene loci.The inhibitory effect of B.velezensis stain SB023 on Fusarium stalk rot in sorghum was evaluated by antagonistic experiment and inhibition experiment using cell-free supernatant from fermentation broth on potato dextrose agar(PDA).【Result】Six fungi strains were isolated from potted sorghum seedlings with stem rot and identified as Fusarium thapsinum and F.oxysporum by morphological characterization and sequence analysis of ITS,TEF-1α,CAM and RPB2.The selected representative strains were further verified by Koch's rule,and the two Fusarium spp.were the pathogens of sorghum stem rot.The results showed that B.velezensis stain SB023 strains had a significant antagonistic effect against F.thapsinum GL002YB2-4 and F.oxysporum GL002NC3-1,with inhibition rates of 42.89%and 58.52%,respectively.The results of further inhibition experiment of the cell-free supernatant indicated that the SB023 fermentation broth significantly inhibited the growth of aerial hyphae of the two pathogenic fungi on PDA.Microscopic examination showed that protoplast aggregation and bubble swelling of the hyphae of F.thapsinum GL002YB2-4 or F.oxysporum GL002NC3-1 occurred with the increase of SB023 fermentation broth content on PDA,indicating that there were active substances inducing hyphae distortion in the fermentation broth of the B.velezensis.【Conclusion】Two pathogens of Fusarium stalk rot in sorghum were clarified,among which F.oxysporum was reported for the first time,and the inhibitory activity of B.velezensis against the two pathogens was evaluated,providing a reference for green prevention and control of Fusarium stalk rot in sorghum.
作者
罗映清
赵欢
谭兆云
文国琴
杨春艳
张廷富
LUO Yingqing;ZHAO Huan;TAN Zhaoyun;WEN Guoqin;YANG Chunyan;ZHANG Tingfu(College of Life Science,China West Normal University,Nanchong 637009,Sichuan,China;College of Agriculture,Forestry,and Food Engineering,Yibin University,Yibin 644000,Sichuan,China)
出处
《四川农业大学学报》
北大核心
2025年第1期128-137,175,共11页
Journal of Sichuan Agricultural University
基金
四川省自然科学基金(24NSFSC1772)
西华师范大学博士启动项目(20E060)。
