甘蔗内生菌分离鉴定及功能多样性研究

为探究甘蔗内生菌多样性组成及相关特性,本研究采用稀释涂板法分离并结合形态观察和分子标记(gyrB,rpoB, ITS, 16S rDNA)进行鉴定。结果表明,从12个栽培品种(系)和5个野生种无性系的根、茎、叶组织中共分离到细菌589株、放线菌34株和真菌46株;细菌中固氮菌有41株,溶磷菌有98株,解钾菌有52株,对黄曲霉和禾谷镰刀菌具有拮抗作用分别有44株和35株。内生细菌分属21个属,其中芽孢杆菌属、伯克氏菌属、肠杆菌属和泛菌属为优势属;内生真菌分属于枝顶孢属、链格孢属、曲霉属、镰刀菌属、枝孢属等17个属,而放线菌仅为链霉菌属。具有潜在植物益生功能的菌株主要集中在芽孢杆菌属、伯克氏菌属、肠杆菌属、假单胞菌属、不动杆菌属、类芽孢杆菌属及泛菌属。本研究显示甘蔗栽培品种(系)和野生种无性系均含有丰富的内生菌资源,且栽培品种(系)所含内生菌在数量和多样性上均高于野生种无性系;12个栽培品种(系)间所分离到的内生细菌大部分相同,但也存在差异。通过初步的功能鉴定,筛选出一些具有应用潜力的益生微生物,为开发相应功能的生物菌剂奠定基础。

Isolation,Identification and Multiple Function Analyses of Sugarcane Endophytes

To investigate the diversity composition of sugarcane endophytes and the beneficial characteristics, dilution-plating, morphological observation and molecular marker (gyrB gyrase beta-subunit], rpoB RNA polymerase beta-subunit], ITS integrated transcribed space], 16S rDNA) were used in the combination and several room assays such as phosphate-, potassium-solubilizations and antagonistism tests. The results showed that 589 bacterial, 34 actinomycetic and 46 fungal strains were isolated from the root, stem and leaf tissues of 12 sugarcane varieties and 5 wild species, of which 41 strains could fix nitrogen, 98 and 52 strains solubilize phosphate and potassium respectively, 44 and 35 strains were antagonistic to Aspergillus flavus and Fusarium graminearum, respectively. The endophytic bacteria belonged to 21 genera, among them Bacillus, Burkholderia, Enterobacter and Pantoea were the dominant. The endophytic fungi were classified into 17 genera, Acremonium, Alternaria, Aspergillus, Ceriporia, Cladosporium, etc., while actiomycetes was Streptomyces only. The strains with plant beneficial potentials were mainly clustered into Bacillus, Burkholderia, Enterobacter, Pseudomonas, Acinetobacter, Paenibacillus and Pantoea. The study showed rich endophyte resources both in the sugarcane varieties and wild species interior, and the number and diversity of endophytes in the cultivated varieties were higher than that of wild species. Most of the endogenous bacteria isolated from 12 sugarcane cultivars were the same, but there were differences. Through preliminary functional identification, some probiotics with application potential were screened out, which laid a foundation for the development of biological agents with corresponding functions.