紫花苜蓿根际芽胞杆菌YB-2的鉴定及其生防和促生能力分析  

Identification of Bacillus YB-2 from alfalfa rhizosphere and analysis of its biocontrol and growth-promoting ability

作　　者：史怡梦 张旖璐 张莹 陈佳欣 王丹[1] 申忠宝[2] 郭长虹[1] Shi Yimeng;Zhang Yilu;Zhang Ying;Chen Jiaxin;Wang Dan;Shen Zhongbao;Guo Changhong(Key Laboratory of Molecular Cytogenetics and Genetic Breeding of Heilongjiang Province,College of Life Science and Technology,Harbin Normal University,Harbin 150025,Heilongjiang Province,China;Institute of Forage and Grassland Science,Heilongjiang Academy of Agricultural Sciences,Harbin 150086,Heilongjiang Province,China)

机构地区：[1]哈尔滨师范大学生命科学与技术学院,分子细胞遗传与遗传育种黑龙江省重点实验室,哈尔滨150025 [2]黑龙江省农业科学院草业研究所,哈尔滨150086

出　　处：《植物保护学报》2023年第2期391-401,共11页Journal of Plant Protection

基　　金：国家自然科学基金(31972507,U21A20182);黑龙江省科技攻关项目(2021ZXJ03B05);哈尔滨师范大学研究生创新基金(HSDSSCX2020-04)。

摘　　要：为获得对紫花苜蓿Medicago sativa生长有益的生防菌,以尖孢镰刀菌Fusarium oxysporum为指示菌从紫花苜蓿根际土壤中分离筛选拮抗菌株,基于形态学特征、生理生化特性和16S rDNA与gyrB基因序列分析对其进行鉴定,并评价其对紫花苜蓿根腐病的生防效果以及提高寄主植物耐盐碱胁迫的能力。结果表明,从紫花苜蓿根际土壤中筛选到1株对尖孢镰刀菌有较强拮抗作用的菌株YB-2,该菌株对尖孢镰刀菌菌丝生长的抑制率为71.37%;结合形态学特征、生理生化特性和16S rDNA与gyrB基因序列分析结果将菌株YB-2鉴定为枯草芽胞杆菌Bacillus subtilis。菌株YB-2具有溶解无机磷的能力,且具有产氰化氢、羧甲基纤维素酶、1-氨基环丙烷-1-羧酸脱氨酶、吲哚乙酸和嗜铁素的能力,在NaCl含量为1%~9%、pH 7~9条件下均能生长。菌株YB-2对紫花苜蓿根腐病的相对防效达56.83%;在盐碱条件下,与对照相比,接种YB-2的紫花苜蓿株高极显著增加了17.82%,根长显著增加了28.22%,地上部鲜重和地上部干重分别显著增加了51.12%和48.57%。表明菌株YB-2兼具生防和促生能力,具有开发为防治紫花苜蓿根腐病微生物菌剂的潜力。To obtain biocontrol bacteria benificial to alfalfa,Medicago sativa,antagonistic strains were isolated and screened from alfalfa rhizosphere soil using Fusarium oxysporum as an indicator.The antagonistic strains were identified based on the morphological,physiological and biochemical characteristics,sequence analysis of 16S rDNA and gyrB gene.Biocontrol effects of antagonistic strains against root rot of alfalfa and its ability to improve host plant resistance to saline-alkali stress were evaluated.The results showed that an strain YB-2 was screened from the rhizosphere soil of alfalfa,which had a strong antagonistic effect on F.oxysporum with a inhibition rate of 71.37%on mycelial growth.Combined with the results of morphological,physiological and biochemical characteristics,16S rDNA and gyrB gene sequence analysis,strain YB-2 was identified as Bacillus subtilis.Strain YB-2 was capable of dissolving inorganic phosphorus,producing hydrogen cyanide,carboxymethyl cellulase,1-aminocyclopropane-1-carboxylic acid deaminase,indole-3-acetic and siderophore,and could grow under conditons with a NaCl concentration ranging from 1%to 9%,and a pH value ranging from 7 to 9.The relative biocontrol efficacy of strain YB-2 against alfalfa root rot reached 56.83%.Under saline-alkali conditions,compared with the no-treatment control,the plant height of alfalfa inoculated with YB-2 was significantly increased by 17.82%,the root length of alfalfa inoculated with YB-2 was significantly increased by 28.22%,and the aboveground fresh weight and dry weight were significantly increased by 51.12%and 48.57%,respectively.The results indicated that strain YB-2 has biocontrol and growth promoting abilities,and has the potential to be developed as a biocontrol agent for alfalfa root rot.

关 键 词：紫花苜蓿 芽胞杆菌 根腐病 盐碱胁迫 促生作用 生防效果 

分 类 号：S476.1[农业科学—农业昆虫与害虫防治]