烤烟根际烟碱降解细菌的多样性及其促生特性分析  

Analysis on the diversity and plant growth-promoting characteristics of bacteria in rhizosphere of flue-cured tobacco

作　　者：李永赟 曾宗梁[2] 杨军伟[2] 李广煜 辜运富 LI Yongyun;ZENG Zongliang;YANG Junwei;LI Guangyu;GU Yunfu(College of Resource,Sichuan Agricultural University,Chengdu,Sichuan 611130,China;Panzhihua Branch,Sichuan Tobacco Company,Panzhihua,Sichuan 617099,China)

机构地区：[1]四川农业大学资源学院,四川成都611130 [2]四川省烟草公司攀枝花市公司,四川攀枝花617099

出　　处：《微生物学通报》2021年第10期3632-3641,共10页Microbiology China

基　　金：四川省烟草公司攀枝花市公司项目(202051040024038,PZH2019003);国家自然科学基金(41201256)。

摘　　要：【背景】挖掘兼具烟碱降解和植物根际促生细菌(Plant Growth-Promoting Rhizobacteria,PGPR)功能的细菌资源,有助于保护土壤质量,实现绿色种植。【目的】分析烤烟根际细菌多样性,筛选可降解高浓度烟碱的PGPR。【方法】采用纯培养法在选择性培养基上分离烟碱降解细菌。通过BOXA1R-PCR分析技术、16SrRNA基因测序及系统发育树构建,对菌株的遗传多样性和分类学地位进行分析。进一步评价了菌株的吲哚乙酸(Indole-3-Acetic Acid,IAA)活性、溶磷能力、病原菌拮抗能力等PGPR指标,以筛选出高效PGPR,最后通过盆栽试验验证其促生效果。【结果】分离得到58株烟碱降解细菌,根据BOXA1R-PCR指纹图谱选取11株菌进行16S rRNA基因序列测定,结果表明,58株菌分别属于芽孢杆菌属(Bacillus)、假单胞菌属(Pseudomonas)、拉乌尔菌属(Raoultella)和短波单胞菌属(Brevundimonas)4个属,以芽孢杆菌属(Bacillus)为优势菌属。58株细菌中48.28%的菌株可产IAA,27.59%具备溶磷能力,37.93%具备纤维素降解能力,G2-13、G2-3及HT2-8因促生与抗病特性突出而被筛选为目标功能菌。盆栽试验结果表明,G2-13菌株对幼苗生长的促进作用明显,可使株高与地上部鲜重分别增加33.05%与53.32%。【结论】烤烟根际存在较为丰富多样的烟碱降解细菌,它们在种植业上具有潜在的应用价值。[Background] The mining of bacterial resources with the capabilities of both nicotine degradation and plant growth-promoting would contribute to soil quality protection and green cultivation.[Objective] To analyze the bacterial diversity in the rhizosphere of flue-cured tobacco and screen the plant growth-promoting bacteria that can degrade high concentration of nicotine. [Methods] Pure culture is applied to isolate nicotine-degradation strains with selective medium. The diversity and phylogeny of rhizobacteria were analyzed by transcription factor amplification(BOXA1 R-PCR), 16 S rRNA gene sequencing and phylogeny analysis. The PGPR characteristics of the nicotine-degradation strains were screened via determination of indole-3-acetic acid(IAA) production, phosphorus solubility, antimicrobial activity and other indexes. The growth-promoting effect of the isolates were further confirmed by pot experiment. [Results] Totally, 58 strains of nicotine-degradation bacteria were isolated, and 11 typical strains with different BOXA1 R-PCR fingerprints were selected for 16 S rRNA gene sequencing. Based on the phylogeny analysis, the 58 strains were belonged to four genera including Bacillus, Pseudomonas,Raoultella and Brevundimonas, with Bacillus as the predominant genus. Of the 58 isolates, 48.28%produced IAA, 27.59% were able to dissolve phosphorus, 37.93% could degrade cellulose. Based on the PGPR abilities, three isolates including G2-13, G2-3 and HT2-8 were used to perform pot experiment to further confirm their potential growth-promoting ability. The results showed that when compared to the control, G2-13 could increased the plant height and aboveground fresh weight by 33.05% and 53.32%,respectively. [Conclusion] The tobacco rhizosphere harbors plenty of nicotine-degradation bacterial strains with PGPR capability and have potential application prospects in plant cultivation strains.

关 键 词：烟碱降解 生物多样性 植物根际促生菌 盆栽试验 

分 类 号：S182[农业科学—农业基础科学] S572