珠芽蓼内生固氮菌鉴定及其固氮基因分析  

Identification of endogenous nitrogen-fixing bacteria of Polygonum viviparum and analysis on nitrogen fixation gene(nifH)

作　　者：李振东[1] 陈秀蓉[1] 李鹏[1] 满百膺[1] 王辰月[1] 邹雨坤[1] 徐长林[1] 

机构地区：[1]甘肃农业大学草业学院,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,兰州730070

出　　处：《草地学报》2009年第5期552-557,共6页Acta Agrestia Sinica

基　　金：国家自然基金项目(30471232);甘肃农业大学草业学院草业科学国家级重点学科学术骨干科研项目暨草业生态系统教育部省部共建重点实验室(CY-GG-2006-01)资助

摘　　要：从东祁连山高寒草地采集优势植物珠芽蓼(Polygonum viviparum)并对其内生固氮细菌进行分离、筛选和鉴定。结果表明:从珠芽蓼内分离到14株内生细菌,其中Z22、Z24、Z25、Z27、Z28、Z211、Z214共7株内生细菌具有固氮能力,对菌株Z22的固氮基因(nifH)进行了PCR扩增、测序和系统发育分析,并在GenBank中登录(登录号为EU693342);Z22菌体球形,革兰氏阳性,产芽孢,结合生理生化特征及16SrDNA基因序列测定和同源性分析,鉴定其为球形芽孢杆菌(Bacillus sphaericus),该菌株的16SrDNA序列在GenBank中登录(登录号为EU236749)。本文首次获得了球形芽孢杆菌编码铁蛋白的nifH基因序列。Biological nitrogen fixation is the cleanest and the most economical nitrogen fertilizer because it can reduce the environmental pollution and save energy.Endophytic nitrogen-fixing bacteria,living in plants,can avoid being inhibited by nitrogen compounds and the competition with indigenous microorganisms,showing a higher efficiency of nitrogen fixation.Endophytic nitrogen-fixing bacteria have great potentials to settle the problem of nitrogen sources of the host plants and enhance the adaptability to the environment.Now,more than 20 genera endophytic nitrogen-fixing bacteria have been found from the economic crops and tropical plants,but few studies on the alpine grassland Polygonum viviparum endophytic nitrogen-fixing bacteria are reported.In this study,endogenous nitrogen-fixing bacteria were isolated,screened and identified from Polygonum viviparum which are advantageous plants in alpine grassland in the Eastern Qilian Mountains.14 endophytic bacteria were isolated from Polygonum viviparum,and 7 of them have the ability of nitrogen-fixing.Z22 has been logged in the Gene Bank and has an accession number of EU693342 after PCR amplification,sequencing and phylogenetic analysis on nitrogen-fixing genes（nifH） Z22.Z22 is spherical,Gram-positive,and produces spore.Both 16SrDNA sequence homology analysis and physiological biochemical characteristics analysis indicated that Z22 can be identified as Bacillus sphaericus.16SrDNA sequence of Z22 has got a Gene Bank accession number of EU236749.It is the first time that gene sequence of nifH of encoding ferritin of Bacillus sphaericus was gained.

关 键 词：珠芽蓼 菌株 球形芽孢杆菌 固氮基因 

分 类 号：S182[农业科学—农业基础科学] S154.38