块根块茎类作物内生固氮菌分离鉴定、系统发育与促生特性

发布时间：2018-04-15 20:44

  本文选题：块根块茎 + 内生固氮菌　； 参考：《中国农业科学》2017年01期

【摘要】：【目的】分离鉴定块根块茎类作物内生固氮菌,研究块根块茎类作物内生固氮菌的系统发育,分析测定块根块茎类作物内生固氮菌的促生特性,探讨块根块茎类作物内生固氮菌的种群特点及其随寄主植物的分布特征。【方法】表面消毒块根块茎样品后采用低氮培养法分离内生细菌;通过对菌株nifH的PCR扩增、测序确认分离细菌是固氮菌;通过16S rRNA基因测序、比对初步鉴定菌株,分析菌株的系统发育;通过测定菌株产生ACC脱氨酶、植物激素IAA,拮抗病原真菌研究菌株的促生特性。【结果】从胡萝卜、白萝卜、马铃薯、紫甘蓝、山药、莲藕、芋头、红薯、生姜、甜菜等14个块根块茎类作物的块根、块茎中共分离到内生固氮菌219株。基于16S rRNA序列,这些菌株在系统发育上分别属于Acinetobacter、Arthrobacter、Bacillus、Brevibacillus、Brevibacterium、Chryseobacterium、Citrobacter、Delftia、Domibacillus、Enterobacter、Fictibacillus、Flavimonas、Flavobacterium、Microbacterium、Micrococcus、Paenibacillus,Pantoea、Pseudomonas、Rahnella、Rhizobium、Sphingobacterium、Staphylococcus、Stenotrophomonas、Variovorax,共计24属79种,显示了块根块茎内生固氮菌丰富的种群多样性。鉴定结果显示,219株新分离菌株中有77株系统发育地位属于Bacillus属的23个种,29株属于Pseudomonas属的10个种,二者合计为33种106株,分别占系统发育种数和新分离菌株数的41.77%和48.40%,说明Bacillus和Pseudomonas属是新分离块根块茎类作物内生固氮菌的优势种群。从219株新分离菌株中选取了79株代表菌株进行促生特性研究,结果显示8.86%菌株检测到了ACC脱氨酶活性(0.026-13.76μmolα-丁酮酸·mg~(-1)蛋白·h~(-1)),64.56%菌株检测到了产IAA(0.34-28.99μg·mL~(-1)),6.33%-13.92%菌株具有拮抗病原真菌能力(抑菌率41%-63%)。【结论】在正常生长的块根块茎类作物的块根块茎内栖息着大量内生固氮菌;块根块茎类作物内生固氮菌在科学分类地位上分布广泛,达到24属79种,显示出巨大的生物多样性;Bacillus和Pseudomonas是块根块茎类作物内生固氮菌优势种群;大约10%-60%的块根块茎类作物内生固氮菌显示出产生ACC脱氨酶、产生植物激素IAA、拮抗病原真菌等促进植物生长特性,这可能是内生固氮菌有益于植物生长的内在原因。
[Abstract]:[objective] to isolate and identify endophytic nitrogen-fixing bacteria in tuber tubers, to study the phylogenetic development of endophytic nitrogen-fixing bacteria in tuber tubers, and to analyze the characteristics of endophytic nitrogen-fixing bacteria in tuber tubers.The population characteristics of endophytic nitrogen-fixing bacteria in tuber tubers and their distribution with host plants were studied. [methods] Endophytic bacteria were isolated by low nitrogen culture after surface disinfection of tuber samples, and PCR amplification of the strain nifH was carried out.Sequencing confirmed that the isolated bacteria were nitrogen-fixing bacteria, analyzed the phylogeny of the strains by sequencing 16s rRNA gene, analyzed the phylogeny of the strains, and produced ACC deaminase by determining the strains.Plant hormone IAA, antagonistic characteristics of pathogenic fungi. [results] the root of 14 tuber crops, such as carrot, radish, potato, purple cabbage, yam, lotus root, taro, sweet potato, ginger, beet and so on, was obtained from the root tuber of 14 crops, such as carrot, radish, potato, purple cabbage, yam, lotus root, taro, sweet potato, ginger, beet, etc.219 strains of endophytic nitrogen-fixing bacteria were isolated from tubers.鍩轰簬16S rRNA搴忓垪,杩欎簺鑿屾牚鍦ㄧ郴缁熷彂鑲蹭笂鍒嗗埆灞炰簬Acinetobacter,Arthrobacter,Bacillus,Brevibacillus,Brevibacterium,Chryseobacterium,Citrobacter,Delftia,Domibacillus,Enterobacter,Fictibacillus,Flavimonas,Flavobacterium,Microbacterium,Micrococcus,Paenibacillus,Pantoea,Pseudomonas,Rahnella,Rhizobium,Sphingobacterium,Staphylococcus,Stenotrophomonas,Variovorax,鍏辫��24灞，

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