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草业学报 ›› 2017, Vol. 26 ›› Issue (2): 78-87.DOI: 10.11686/cyxb2016111

• 研究论文 • 上一篇    下一篇

紫花苜蓿根腐病原——厚垣镰刀菌的鉴定及其拮抗菌的筛选

柏玉晶, 姚玉玲, 张振粉, 杨成德*, 薛莉   

  1. 甘肃农业大学植物保护学院,草业生态系统教育部重点实验室,甘肃省草业工程实验室,中-美草地畜牧业可持续发展研究中心,甘肃 兰州730070
  • 收稿日期:2016-03-14 出版日期:2017-02-20 发布日期:2017-02-20
  • 通讯作者: yangcd@gsau.edu.cn
  • 作者简介:柏玉晶(1989-), 女, 甘肃白银人, 硕士。E-mail:1345491709@qq.com
  • 基金资助:
    国家自然科学基金(No.31460639),草业生态系统教育部重点实验室(甘肃农业大学)开放课题项目(CYzs-2011011),甘肃省农牧厅科技支撑项目和甘肃省自然科学基金(145RJZA130)资助

Identification of alfalfa root rot caused by Fusarium chlamydosporum and screening of antagonistic bacterial strains

BAI Yu-Jing, YAO Yu-Ling, ZHANG Zhen-Fen, YANG Cheng-De*, XUE Li   

  1. College of Plant Protection, Gansu Agricultural University, Key Laboratory of Grassland Ecosystem, Ministry of Education, Pratacultural of Gansu Province, Sino-U.S.Center for Grazingland Ecosystem Sustainability, Lanzhou 730070, China
  • Received:2016-03-14 Online:2017-02-20 Published:2017-02-20

摘要: 采用常规组织分离法,对甘肃省武威市紫花苜蓿根腐病菌进行分离和致病性测定,并通过形态学特征和分子鉴定方法对致病性最强的菌株进行鉴定。结果表明,MXGF7可造成紫花苜蓿严重根腐,该病原菌大型分生孢子多纺锤形或镰刀形,大小为3.3~4.7 μm×14.8~32.0 μm;小型分生孢子少,纺锤形或哑铃形,大小2.9~4.2 μm×8.4~18.2 μm;ITS序列及镰孢菌Fu3/Fu4区基因序列分析表明,病原菌均与Fusarium chlamydosporum的相似度达99%,结合形态学特征将该病原菌鉴定为厚垣镰孢菌F. chlamydosporum。采用平板对峙法,从分离自东祁连山高寒草地牧草的123株内生细菌中筛选出61株菌株对F. chlamydosporum有拮抗效果,且抑菌率均在55%,并利用形态特征和16S rDNA基因序列分析将具有稳定拮抗作用265ZY3菌株鉴定为解淀粉芽孢杆菌Bacillus amyloliquefaciens

Abstract: To identify the causal pathogens of alfalfa root rot with strong pathogenicity, pathogens were isolated from alfalfa (Medicago sativa) plants with alfalfa root rot growing in Wuwei City, Gansu Province. The pathogens were identified based on their morphology and by molecular methods. The results showed that the strain MXGF7 caused acute root rot of alfalfa. Most of its macroconidia were fusiform or sickle-shaped (3.3-4.7 μm×14.8-32.0 μm), and its microconidia were fusiform or dumbbell-shaped (2.9-4.2 μm×8.4-18.2 μm). The ITS sequence and the Fu3/Fu4 specificity gene sequence of the pathogenic fungus shared 99% similarity with those of Fusarium chlamydosporum, and so the pathogenic fungus was identified as F. chlamydosporum. We isolated 123 endophytic bacterial strains from alpine grassland in the Eastern Qilian Mountains, and evaluated their ability to antagonize the pathogenic strain of F. chlamydosporum. Sixty-one of the bacterial strains showed an antifungal ratio greater than 55%. The most antagonistic bacterium, strain 265ZY3, was identified as Bacillus amyloliquefaciens based in its morphology and 16S rDNA gene sequence.