| 摘要: |
| 为了解苜蓿镰孢菌根腐病病原的致病性差异和致病机制，本研究对分离自河北省黄骅市和张家口市宣化区部分苜蓿种植地苜蓿根腐病样品的150株镰孢菌（Fusariumspp.）（2015年分离获得72株，2016年分离获得78株），采用平皿法进行了致病性测定，利用分子生物学技术对所分离获得的镰孢菌菌株是否具有产脱氧雪腐镰刀菌烯醇（DON）和雪腐镰刀菌烯醇（NIV）毒素的潜力进行了检测，并对获得的粗毒素进行了生物活性测定。结果表明：分离获得的镰孢菌对萌发的苜蓿种子均具有致病性，但致病性强弱存在差别，除三线镰孢（F.tricinctum）和大部分木贼镰孢（F.equiseti）菌株致病性较弱外，大多数镰孢菌菌株表现出较强致病性；在所获得镰孢菌菌株中，菌株KD3（F.oxysporum）、菌株QD3-2（F.oxysporum）、菌株N6-1（F.equiseti）、菌株N9-2（F.acuminatum）、菌株NT1-1（F.acuminatum）和菌株QD10-1（F.acuminatum）共6株镰孢菌具有产NIV毒素潜力，未发现具有产DON毒素潜力的菌株；将NIV毒素化学型菌株QD3-2发酵培养后经有机溶剂萃取获得粗毒素，对其进行的生物活性测定结果表明，粗毒素对苜蓿种子的萌发具有较强抑制作用。本研究结果为探讨苜蓿镰孢菌根腐病致病机理、有效防治苜蓿根腐病和保障苜蓿安全生产提供了一定基础。 |
| 关键词: 苜蓿根腐病 镰孢菌 致病性 毒素化学型 粗毒素 |
| DOI：10.11841/j.issn.1007-4333.2018.05.009 |
| 投稿时间：2017-09-12 |
| 基金项目:公益性行业（农业）科研专项经费项目（201303057） |
|
| Detection of pathogenicity and mycotoxin chemotypes of Fusarium causing alfalfa root rot |
|
KONG Qianqian, QIN Feng, ZHANG Yuzhu, MA Zhanhong, LIU Zhilong, WANG Haiguang
|
| (College of Plant Protection, China Agricultural University, Beijing 100193, China) |
| Abstract: |
| Alfalfa (Medicago sativa) is widely cultivated in the world.Alfalfa root rot has become one of the most important factors resulting in quality decline and yield losses of alfalfa.To explore the difference in pathogenicity and the pathogenic mechanism of Fusarium causing alfalfa root rot,150 Fusarium strains isolated from the samples of alfalfa root rot collected from Huanghua and Xuanhua District in Hebei Province,China,among which 72 strains were isolated in 2015 and 78 strains were isolated in 2016,were used in this study.Pathogenicity determination of all Fusarium strains was conducted using plate method.The DON (deoxynivalenol) and NIV (nivalenol) mycotoxins producing potentialities of the strains were investigated.And bioactivity tests of crude mycotoxins derived from strain QD3-2 (F.oxysporum),which was identified as NIV chemotype,were performed.The results showed that all the isolated Fusarium strains induced pathogenicity on germinated alfalfa seeds,but there were differences among the pathogenic intensities.Most Fusarium strains exhibited strong pathogenicity except F.tricinctum strains and most F.equiseti strains.Strain KD3 (F.oxysporum),strain QD3-2 (F.oxysporum),strain N6-1 (F.equiseti),strain N9-2 (F.acuminatum),strain NT1-1 (F.acuminatum) and strain QD10-1 (F.acuminatum) displayed potential to produce NIV,and there were no strains showed DON producing potentiality.After fermentation,crude mycotoxins were extracted from strain QD3-2 using organic solvents.The bioactivity tests demonstrated that the crude mycotoxins had strong inhibitory effects on the germination of alfalfa seeds.This study would provide theoretical references for further studies on the pathogenic mechanism of pathogens causing alfalfa root rot,efficient management of alfalfa root rot and alfalfa production safety. |
| Key words: alfalfa root rot Fusarium pathogenicity mycotoxin chemotype crude mycotoxin |
