文献类型：期刊文献

中文题名：内生假单胞菌的生防促生评价及发酵条件优化

英文题名：Evaluation of Biocontrol and Growth-promoting Properties of Endophytic Pseudomonas and Optimization of Fermentation Conditions

作者：薛寒[1] 姜宁[1] 李永[1]

第一作者：薛寒

机构：[1]中国林业科学研究院森林生态环境与自然保护研究所,生物多样性保护国家林业和草原局重点实验室,北京100091

年份：2025

卷号：5

期号：5

起止页码：53-63

中文期刊名：陆地生态系统与保护学报

外文期刊名：Terrestrial Ecosystem and Conservation

基金：国家自然基金青年基金(32201574)。

语种：中文

中文关键词：松枯梢病;松色二孢;生物防治;植物促生;假单胞菌属;发酵

外文关键词：pine shoot blight;Diplodia sapinea;biological control;plant growth promotion;Pseudomonas sp.;fermentation

分类号：S718.8

摘要：【目的】为应对由松色二孢(Diplodia sapinea)引起的重要松树病害松枯梢病,从兴安落叶松(Larix gmelinii)健康根系中筛选高效拮抗内生菌,阐明其分类地位、生防机制及促生潜力,并优化其发酵工艺,为开发新型林木生防菌剂提供科学依据。【方法】采用组织匀浆法分离内生细菌,通过平板对峙法和倒扣平板法筛选对松色二孢有显著拮抗活性的菌株。利用定性和定量分析方法,评价菌株产铁载体、解磷及分泌吲哚-3-乙酸的能力。结合形态学、生理生化特征及基于16S rRNA基因序列的最大似然进化树构建,确定菌株分类地位。通过单因素实验,优化其发酵培养基组分及培养条件。【结果】从128株内生菌株中,筛选出一株优势菌株N2-3-1-14,其平板对峙抑菌圈直径达4.81 cm,产生的挥发性有机物抑菌率高达61.96%。该菌株兼具优异的促生性状,铁载体产生指数为2.86,IAA分泌量达14.29μg/mL,且具备显著的溶磷活性。系统分类学分析将其鉴定为加拿大假单胞菌(Pseudomonas canadensis)。发酵优化结果表明,最佳碳源为乳糖,最佳氮源为蛋白胨;在初始pH值6.5~7.0、温度28~30℃条件下培养72 h的发酵液抑菌活性达到峰值。【结论】加拿大假单胞菌菌株N2-3-1-14兼具显著的直接拮抗与挥发性物质介导的双重抑菌活性,且促生潜力优异,在松枯梢病生物防治及促进林木生长领域有广阔的潜在应用前景。
【Objective】To address the pine shoot blight caused by the severe fungal pathogen Diplodia sapinea,this study aims to screen high-efficiency antagonistic endophytic bacteria from healthy tissues of Larix gmelinii.The study sought to identify the taxonomic status of the dominant strain,evaluate its biocontrol and growth-promoting potential,and optimize its fermentation process to provide a theoretical basis for developing novel microbial biocontrol agents.【Methods】Endophytic bacteria were isolated using the tissue homogenization method.Strains with significant antagonistic activity against D.sapinea were screened via dual culture assays and inverted plate methods.The abilities to produce siderophores,solubilize phosphate,and secrete indole-3-acetic acid(IAA)were evaluated using qualitative and quantitative assays.The strain was identified based on morphological,physiological,and biochemical characteristics,combined with a maximum likelihood(ML)phylogenetic tree constructed from 16S rRNA gene sequences.Fermentation medium components and culture conditions were optimized using single-factor experiments.【Results】Among 128 isolated endophytes,the dominant strain N2-3-1-14 exhibited the best performance.It produced an inhibition zone of 4.81 cm in dual culture and achieved an inhibition rate of 61.96%via volatile organic compounds.The strain possessed multiple growth-promoting traits,with a siderophore production index of 2.86,IAA secretion of 14.29μg/mL,and significant phosphate-solubilizing activity.Phylogenetic analysis identified the strain as Pseudomonas canadensis.Optimization results showed that the optimal carbon and nitrogen sources were lactose and peptone,respectively.The fermentation broth achieved peak antifungal activity when cultured at an initial pH of 6.5-7.0 and 28-30℃for 72 h.【Conclusion】The endophytic strain P.canadensis N2-3-1-14 demonstrates significant antifungal activity through both direct antagonism and gas-mediated mechanisms,along with excellent plant growth-promoting potential.It holds high application value for the biological control of pine shoot blight and the promotion of forestry growth.