摘要: |
【目的】明确河西走廊制种玉米根腐病的主要致病菌,并筛选对其具有拮抗作用的内生菌,为玉米根腐病的生物防治提供参考。【方法】采用组织分离法从患玉米根腐病的病株中分离纯化病原菌,按柯赫氏法则检测其致病性;从玉米健株内分离内生菌,通过平板对峙法筛选拮抗菌;分别采用形态学和分子生物学方法对致病菌FW8和5株内生拮抗菌Z8,Z42,Z142,Z51和Z46进行鉴定;采用盆栽试验和大田试验验证5株内生拮抗菌对玉米根腐病的防治效果及其对玉米植株的促生作用。【结果】采用组织分离法从患玉米根腐病病株中共分离得到9株病原菌,其中FW8菌株对玉米具有较强致病力,鉴定为禾谷镰刀菌(Fusarium graminearum)。从玉米健株内分离获得56株内生细菌,其中5株内生菌(Z8、Z42、Z142、Z51、Z46)高效拮抗,平均抑菌率均大于65.05%。经形态学、分子生物学鉴定及系统发育树构建,鉴定菌株Z8和Z42为多粘类芽孢杆菌(Paenibacillus polymyxa),菌株Z46为解淀粉芽孢杆菌(Bacillus amyloliquefaciens),菌株Z142和Z51为贝莱斯芽孢杆菌(B.velezensis)。盆栽和大田试验结果表明,5株内生拮抗菌对玉米根腐病均有较好防治效果,最佳防效高达66.05%;此外,5株内生拮抗菌对玉米植株均有显著促生效果(P<0.05)。【结论】禾谷镰刀菌(F.graminearum)可导致制种玉米根腐病发生,多粘类芽孢杆菌P.polymyxa Z8、P.polymyxa Z42,贝莱斯芽孢杆菌B.velezensis Z142、B.velezensis Z51和解淀粉芽孢杆菌B.amyloliquefaciens Z46均对制种玉米根腐病具有明显防治作用,同时对玉米植株有良好的促生效果。 |
关键词: 制种玉米 根腐病 禾谷镰刀菌 内生拮抗菌 病原鉴定 |
DOI:DOI:10.13207/j.cnki.jnwafu.2024.12.010 |
分类号: |
基金项目:甘肃省重点研发项目(22YF7NG128);国家自然科学基金地区项目(41867010) |
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Identification of root rot pathogens of corn seed production and screening of endophytic antagonistic bacteria |
FU Wenjiang1,2, ZHAO Yunchen1, Cao Jianxin1
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1.College of Agricultural and Ecological Engineering,Hexi University,Zhangye,Gansu 734000,China;2.College of Resources and Environment,Northwest A&F University,Yangling,Shaanxi 712100,China
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Abstract: |
【Objective】This study identified main pathogenic fungus of corn root rot and screened antagonistic endophytic bacteria in the Hexi Corridor to provide reference for the biological control of maize root rot.【Method】Tissue isolation method was used to isolate and purify pathogenic bacteria from diseased maize root rot plants,and their pathogenicity was tested according to Koch’s law.Endophytic bacteria were isolated from healthy maize plants,and antagonistic bacteria were screened by plate stand-off method.The pathogenic bacterium of FW8 and five endophytic antagonistic bacteria strains of Z8,Z42,Z142,Z51 and Z46 were identified by morphological and molecular biological methods.The efficacy of endophytic antagonistic bacteria strains in the control of maize root rot and their growth-promoting effects on maize plants was then verified by using pot and field tests.【Result】A total of nine strains of pathogenic bacteria were isolated from maize root rot affected plants using tissue isolation method,among which FW8 was identified as Fusarium graminearum with the strongest pathogenicity.Fifty-six strains of endophytic bacteria were isolated from healthy maize plants, of which five (Z8, Z42, Z142, Z51 and Z46) were highly antagonistic,with an average inhibition rate of >65.05%. After morphological and molecular biological identification,Z8 and Z42 were Paenibacillus polymyxa,Z46 was Bacillus amyloliquefaciens,and Z142 and Z51 were B.velezensis through phylogenetic tree construction.The five endophytic antagonist strains showed significant root rot control effects in both pot and field trials,with the best preventive effect of 66.05%.The five endophytic antagonist strains also had significant growth promotion effects on maize plants (P<0.05).【Conclusion】F.graminearum caused root rot of seed corn,and screened strains of P.polymyxa Z8,P.polymyxa Z42,B.velezensis Z142,B.velezensis Z51 and B.amyloliquefaciens Z46 had significant biological control effects on corn root rot in seed corn and good growth promotion effects on maize plants. |
Key words: corn seed production root rot Fusarium graminearum endophytic antagonistic bacteria identification pathogen |