旱稻联合固氮菌的分离、鉴定及功能特性  

Isolation,identification and functional characteristics of associative nitrogen-fixing bacteria in upland rice

作　　者：胡应平 林冬梅[1,2] 胡弘正 吴颖 谭兆玲 刘斌[1,2] 林占熺[1,2] HU Yingping;LIN Dongmei;HU Hongzheng;WU Ying;TAN Zhaoling;LIU Bin;LIN Zhanxi(College of Life Sciences,Fujian Agriculture and Forestry University;National Engineering Research Center of JUNCAO Technology,Fujian Agriculture and Forestry University,Fuzhou,Fujian 350002,China)

机构地区：[1]福建农林大学生命科学学院 [2]福建农林大学国家菌草工程技术研究中心,福建福州350002

出　　处：《福建农林大学学报（自然科学版）》2024年第6期797-807,共11页Journal of Fujian Agriculture and Forestry University:Natural Science Edition

基　　金：中国援巴新菌草、旱稻技术项目(271/KH200039A)。

摘　　要：【目的】通过研究旱稻内生固氮菌的生理特性,筛选出具有较强固氮和促生特性的菌株,为生物菌剂的开发提供依据。【方法】采用联合固氮固体培养基培养方法,从成熟期旱稻的根、茎、叶、谷粒中分离内生固氮菌,并进行系统进化分析、形态学鉴定、生理生化鉴定以及促生作用和拮抗禾谷镰刀菌等特性的研究。【结果】获得27株内生固氮菌,涵盖3个门,分别为芽孢杆菌门、变形菌门和放线菌门。其中,芽孢杆菌门的芽孢杆菌属为优势菌。从根中分离的URR05和URR37菌株经革兰氏染色呈紫红色,其余菌株呈紫色。所有菌株均能够利用葡萄糖,属于发酵型细菌,且为嗜温型微生物,最适温度为30~45℃,具有固氮、分泌生长素和1-氨基环丙烷羧酸脱氨酶、产铁载体、溶磷等特性。枯草芽孢杆菌URR64的固氮酶活性和吲哚-3-乙酸的质量浓度最高,分别为253.82 U·L^(-1)和19.19 mg·L^(-1);斯特氏杆菌URS02分泌的1-氨基环丙烷羧酸的质量浓度最高(1031.43 ng·mL^(-1)),且显著高于阳性对照组(褐球固氮菌)。1.03×10^(8)CFU·mL^(-1)的混合联合固氮菌对旱稻幼苗具有显著促生效果,芽孢杆菌属固氮菌对禾谷镰刀菌具有显著的拮抗作用。【结论】旱稻内生固氮菌群较为丰富,且具有多种功能。【Objective】Endophytic nitrogen-fixing bacteria with high nitrogen fixation efficiency and growth-promoting function were screened from upland rice through physical trait analysis to provide theorical reference for developing biological agents in agricultural production.【Method】With solid medium for diazotrophs,endophytic nitrogen-fixing bacteria were isolated from the root,stem,leaf and grain of upland rice at the ripening stage.And they were further studied for phylogenetic relationship,morphological characteristics,physiological and biochemical characteristics,biological characteristics,growth-promoting effect and antagonistic effect against Fusarium graminearum.【Result】A total of 27 nitrogen-fixing endophytes were obtained,covering 3 phyla,namely Bacillota,Proteobacteria and Actinomycetota.The Bacillus genus of Bacillota was the dominant bacteria.By Gram stain,strain URR05 and URR37 isolated from the root were claret,and the others were purple.All of them can utilize glucose,and belonged to fermentative bacteria and thermophilic microorganisms with an optimal temperature of 30-45℃;they also shared characteristics such as nitrogen fixation,secretion of auxin and 1-aminocyclopropanecarboxylate acid(ACC)deaminase,iron carriers production and phosphate solubilization.Bacillus subtilis URR64 had the highest nitrogenase activity(253.82 U·L^(-1))and the highest mass concentration of 3-indoleacetic acid(19.19 mg·L^(-1)),while B.stercoris URS02 had the highest mass concentration of ACC(1031.43 ng·mL^(-1)),which was significantly higher than the control(nitrogen-fixing bacterium Azotobacter chroococcum).The mixed nitrogen-fixing bacteria at the concentration of 1.03×10^(8)CFU·mL^(-1)had a significant promoting effect on the growth of upland rice seedlings,and the nitrogen-fixing bacteria of Bacillus genus exerted significant antagonistic effect against F.graminearum.【Conclusion】The endophytic nitrogen-fixing bacteria in upland rice are abundant and have multiple functions.

关 键 词：旱稻 联合固氮菌 分离与鉴定 功能特性 拮抗作用 

分 类 号：Q939.1[生物学—微生物学]