摘要
为了研究紫花苜蓿内生和非内生细菌的遗传多样性和促生能力,从甘肃省3个栽培生态区域的5个紫花苜蓿品种分离内生(植株种子、花、叶、茎、根表皮、根中柱和根瘤)和非内生(根际土壤和田间土壤)细菌,对其进行16SrRNA限制性片段长度多态性(RFLP)、16SrRNA基因、结瘤基因nodC和固氮基因nifH片段测序分析,以及分泌生长素IAA和溶磷的能力。结果表明:共分离得到103株细菌,其中73株为内生细菌,30株为非内生细菌,但叶片中未分离到细菌。所分离的菌株归属于15个属的17个种,其中以Rhizobium radiobacter(20)和Ensifer meliloti(32)菌株为代表的α-变形菌纲(56)为主要组分,且非内生细菌遗传多样性(H=1.997)比内生细菌(H=1.885)丰富。内生根瘤菌株结瘤nodC和固氮基因nifH基因高度保守,而非内生根瘤菌株变异程度高,以及非内生根瘤菌株分泌生长素IAA和溶磷能力强于内生根瘤菌株。
To identify the genetic diversity of endophytic and non-endophytic bacteria of Medicago sativa,the endophytic(seed,flower,stem,root epidermis,root stele,nodule)and non-endophytic(rhizosphere soil and field soil)bacteria isolates were collected from five alfalfa varieties in three cultivated ecological areas in Gansu province.Genetic diversity of endophytic and non-endophytic bacteria was identified by using 16S rRNA restriction fragment length polymorphism fingerprinting(RFLP),and sequencing analysis of 16S rRNA gene,symbiotic genes nodC and nifH,as well as the ability of IAA production and phosphate solubilization were investigated in the present study.The results showed that 103 bacteria isolates were obtained totally,among all the isolates there were 73 and 30 isolates that belong to endophytes and non-endophytes,respectively,whereas no bacteria were isolated from leaves of M.sativa.These 103 isolates were clustered into 17 species of 15 genus,among which Alphaproteobacteria(56),represented by Rhizobium radiobacter(20)and Ensifer meliloti(32),were the main components.The genetic diversity of non-endophytic bacteria(H=1.997)was more abundant than that of endophytic bacteria(H=1.885).The nodC and nifH genes of endophytic rhizobia were highly conservative,while that of non-endophytic rhizobia were much more variable.Compared with the endophytic rhizobia,non-endophytic rhizobia were more capable of secreting IAA and solubilizing phosphate.
作者
康文娟
姜哲浩
师尚礼
KANG Wen-juan;JIANG Zhe-hao;SHI Shang-li(College of Grassland Science,Gansu Agricultural University/Key Laboratory for Grassland Ecosystem of Ministry of Education/Pratacultural Engineering Laboratory of Gansu Province/Sino-U.S.Centers for Grazing Land Ecosystem Sustainability,Lanzhou 730070,China)
出处
《草原与草坪》
CAS
CSCD
2018年第6期34-47,共14页
Grassland and Turf
基金
国家自然科学基金(31560666)资助
关键词
紫花苜蓿
内生细菌
非内生细菌
遗传多样性
分泌IAA和溶磷能力
Medicago sativa
endophytic bacteria
non-endophytic bacteria
genetic diversity
IAA production and phosphate solubilization
