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草业学报 ›› 2024, Vol. 33 ›› Issue (3): 174-185.DOI: 10.11686/cyxb2023151

• 研究论文 • 上一篇    

2株青贮玉米根际固氮菌的筛选鉴定及促生作用研究

孟超楠1(), 赵玉洁1(), 陈佳欣1, 张旖璐1, 王彦佳1, 冯丽荣2, 孙玉刚1, 郭长虹1()   

  1. 1.黑龙江省分子细胞遗传与遗传育种重点实验室,哈尔滨师范大学生命科学与技术学院,黑龙江 哈尔滨 150000
    2.黑龙江国宏节能环保有限公司,黑龙江 哈尔滨 150028
  • 收稿日期:2023-05-08 修回日期:2023-06-28 出版日期:2024-03-20 发布日期:2023-12-27
  • 通讯作者: 郭长虹
  • 作者简介:. E-mail: kaku3008@126.com
    孟超楠(1999-),女,河南驻马店人,在读硕士。E-mail: 3323466192@qq.com
    赵玉洁(1996-),女,贵州贵阳人,硕士。E-mail: 347111947@qq.com第一联系人:(孟超楠、赵玉洁并列第一作者)
  • 基金资助:
    国家自然科学基金(U21A20182);黑龙江省科技攻关项目(2021ZXJ03B05);哈尔滨师范大学研究生创新基金(HSDSS CX2021-05)

Screening and identification of two strains of nitrogen-fixing bacteria from the silage maize rhizosphere and their roles in plant growth promotion

Chao-nan MENG1(), Yu-jie ZHAO1(), Jia-xin CHEN1, Yi-lu ZHANG1, Yan-jia WANG1, Li-rong FENG2, Yu-gang SUN1, Chang-hong GUO1()   

  1. 1.Heilongjiang Provincial Key Laboratory of Molecular Cellular Genetics and Genetic Breeding,College of Life Science and Technology,Harbin Normal University,Harbin 150000,China
    2.Heilongjiang Guohong Energy Conservation and Environmental Protection Co. ,Ltd. ,Harbin 150028,China
  • Received:2023-05-08 Revised:2023-06-28 Online:2024-03-20 Published:2023-12-27
  • Contact: Chang-hong GUO

摘要:

为了获得优良的固氮菌,并评价其对青贮玉米的促生效果,本研究采用稀释涂布平板法,利用阿须贝氏固体培养基从青贮玉米根际土壤中分离筛选到10株固氮菌,对其固氮能力进行分析,结果表明,菌株ZL-2和ZL-13的固氮能力较强,菌株ZL-2的固氮量为1.07 μg·mL-1,ZL-13的固氮量为0.95 μg·mL-1。通过细菌形态学、16S rDNA序列分析和生理生化特征,确定菌株ZL-2为生癌肠杆菌和ZL-13为成团泛菌。对2株固氮菌的促生特性进行分析,结果表明,2个菌株具有泌铵能力、溶磷能力、产嗜铁素能力和合成吲哚-3-乙酸(IAA)的能力。盆栽试验结果表明,接种固氮菌ZL-2和ZL-13能够显著提高青贮玉米的株高、根长、地上和地下干、鲜重(P<0.05)。田间试验结果表明,2株固氮菌单接种和双接种均能提高青贮玉米的株高、茎粗、产量、粗蛋白含量和全磷含量(P<0.05)。接种2株固氮菌的青贮玉米,其氮代谢和氨同化相关基因(ZmAMT-4ZmAMTBZmGOGAT2ZmGS1-3)的表达量显著提高(P<0.05)。因此,2株固氮菌具有较好的促生特性,在提高青贮玉米的产量和品质方面发挥了重要作用,是开发微生物菌剂的优质菌种资源。

关键词: 青贮玉米, 固氮菌, 泌铵, 促生作用, 基因表达

Abstract:

The aim of this study was to screen for high-quality nitrogen-fixing bacteria and evaluate their growth-promoting effects on silage maize (Zea mays). The dilution spread plate method with Ashby solid medium was used to screen and screen ten strains of nitrogen-fixing bacteria from the rhizosphere soil of silage maize. The nitrogen-fixation capabilities of the strains were analyzed. The results indicated that cultures of ZL-2 and ZL-13 exhibited strong nitrogen-fixing abilities (1.07 and 0.95 μg·mL-1, respectively). On the basis of their morphological characteristics, 16S rDNA sequence, and physiological and biochemical characteristics, ZL-2 was identified as Enterobacter cancerogenus, and ZL-13 was identified as Pantoea agglomerans. The growth-promoting characteristics of these two strains were analyzed, and both bacteria were found to secrete ammonium and siderophores, solubilize phosphate, and synthesize indole-3-acetic acid. In a pot experiment, compared with uninoculated silage maize plants, those inoculated with the nitrogen-fixing strains ZL-2 and ZL-13 showed significantly increased plant height, root length, aboveground and underground dry weights, and fresh weight (P<0.05). In a field experiment, compared with uninoculated silage maize plants, those inoculated with one or both of the nitrogen-fixing strains showed significantly increased plant height, stem diameter, yield, crude protein content, and total phosphorus content (P<0.05). Silage maize plants inoculated with these two nitrogen-fixing strains showed significantly increased expression levels of genes related to nitrogen metabolism and ammonia assimilation (ZmAMT-4ZmAMTBZmGOGAT2, and ZmGS1-3) (P<0.05). Therefore, these two nitrogen-fixing bacterial strains have favorable growth-promoting characteristics. Given their important role in enhancing the yield and quality of silage maize, they are valuable resources for the development of microbial agents.

Key words: silage maize, nitrogen-fixing bacteria, ammonium-secreting, growth-promoting function, gene expression