草地早熟禾种带可培养细菌多样性及18个菌株促生特性研究  

A study of the diversity of cultivable seed-borne bacteria in Poa pratensis and the growth-promoting characteristics of 18 bacterial strains

作　　者：谢金晶 朱绍玮 黄荣 杨杰 侯瑄 张振粉[1,2] XIE Jin-jing;ZHU Shao-wei;HUANG Rong;YANG Jie;HOU Xuan;ZHANG Zhen-fen(College of Pratacultural Science,Gansu Agricultural University,Lanzhou 730070,China;Key Laboratory of Grassland Ecosystem,Ministry of Education,Engineering Laboratory of Gansu Province,Sino-U.S.Center for Grassland Ecosystem Sustainability,Lanzhou 730070,China)

机构地区：[1]甘肃农业大学草业学院,甘肃兰州730070 [2]草业生态系统教育部重点实验室,中-美草地畜牧业可持续发展研究中心,甘肃兰州730070

出　　处：《草业学报》2024年第12期134-146,共13页Acta Prataculturae Sinica

基　　金：国家自然科学基金(32060369);甘肃省杰出青年基金(20JR10RA562);草业生态系统教育部重点实验室-人才培育项目(KLGE202203)资助。

摘　　要：为探究草地早熟禾种带可培养细菌的多样性并筛选其中促生功能优异的菌株,本研究采用稀释涂布平板法对3个品种草地早熟禾种带可培养细菌进行分离,得到30个细菌分离物。通过16S rRNA序列分析,对18株形态特征具有差异的代表性分离物进行鉴定并构建系统发育树。结果表明,分离并鉴定的种带可培养细菌有厚壁菌门、放线菌门和变形菌门,分属于6个属,分别为芽孢杆菌属、类芽孢杆菌属、假单胞菌属、短小杆菌属、寡养单胞菌属和欧文氏菌属,其中芽孢杆菌属为3个品种的共有属。对18株细菌的固氮、产吲哚-3-乙酸(indole-3-acetic acid,IAA)、溶磷、产胞外酶(蛋白酶、纤维素酶、淀粉酶)能力测定发现,菌株BM8和KTJ14同时具有上述功能中的3种。此外,采用结晶紫染色法和泳动培养基对菌株的生物被膜形成能力及泳动能力这2种促生相关的生物学特性进行测定,并讨论了生物被膜形成能力和泳动性与菌株促生功能之间的相关性,其中,KTJ16是生物被膜形成能力最强的菌株,SW5和KTJ18的泳动能力显著强于其他菌株。综合几种特性,最终筛选出具有优异促生特性的菌株为BM8、SW5、KTJ14、KTJ16和KTJ18。This study investigated the diversity of cultivable seed-borne bacteria of Poa pratensis to identify strains with superior plant growth-promoting properties.The cultivable seed-borne bacteria of three varieties of P.pratensis were isolated by the dilution plate method and 30 bacterial isolates were obtained.Through 16S rRNA sequence analysis,18 representative isolates with different morphological characteristics were identified and phylogenetic trees were constructed.It was found that the isolated cultivable seed-borne bacteria so identified belonged to the phyla Firmicutes,Actinobacteria and Proteobacteria,and included six genera,Bacillus,Paenibacillus,Pseudomonas,Curtobacterium,Stenotrophomonas and Erwinia.Among them,Bacillus is the common genus of three varieties.The nitrogen fixation,indole-3-acetic acid-producing,phosphorus solubilization and extracellular enzyme(protease,cellulase and amylase)production of the 18 bacterial taxa were determined and it was found that strains designated BM8 and KTJ14 possessed all three of the above functions.In addition,the biofilm formation ability and swimming motility of the strains were determined by crystal violet staining and swimming medium,and the correlation between these two traits and the growth-promoting function of isolated taxa is discussed.A strain designated KTJ16 had the strongest biofilm formation ability,and the swimming motility of taxa designated SW5 and KTJ18 was significantly stronger than that of other taxa.Based on multiple characteristics,the strains with superior growth-promoting characteristics were determined to be BM8,SW5,KTJ14,KTJ16 and KTJ18.

关 键 词：固氮 溶磷 产IAA 产胞外酶 生物被膜 泳动能力 

分 类 号：S688.4[农业科学—观赏园艺]