Biodiv Sci ›› 2020, Vol. 28 ›› Issue (8): 1018-1025.DOI: 10.17520/biods.2019366

• Original Papers • Previous Articles     Next Articles

Diversity of endophytic diazotrophs isolated from Oryza alta

Liping Liu1, Ruifeng Song1, Fu Zhang1,3, Xiuxiang Zhang1, Guixiang Peng2,*(), Zhiyuan Tan1,*()   

  1. 1 College of Agriculture, South China Agricultural University, Guangzhou 510642
    2 College of Resource and Environment, South China Agricultural University, Guangzhou 510642
    3 Baoding Lucky Middle School, Hebei Province, Baoding, Hebei 071051
  • Received:2019-11-12 Accepted:2020-03-03 Online:2020-08-20 Published:2020-06-12
  • Contact: Guixiang Peng,Zhiyuan Tan

Abstract:

Forty-three strains of endophytic nitrogen-fixing bacteria were obtained from wild rice Oryza alta, and grown on nitrogen-free medium. Their potential nitrogen-fixing ability was determined with the acetylene reduction method and a PCR amplification of the nifH gene fragment. The obtained isolates were grouped into six groups (I, II, III, IV, V, VI) based on their DNA patterns of IS-PCR and protein patterns of SDS-PAGE. The 16S rRNA gene sequence analysis identified representative strains, suggesting that group I belonged to Raoultella terrigena, group II to Klebsiella quasipneumoniae subsp. quasipneumoniae, group III to Burkholderia vietnamiensis, group IV to genus Enterobacter, group V to Pseudomonas mendocina, and group VI to Phytobacter diazotrophicus. A Biolog plate test showed strains from differing groups had significant differences in carbon source utilization, often clustering consistently within IS-PCR and SDS-PAGE patterns. The diversity of endophytic nitrogen-fixing bacteria in wild rice indicates that endophytic bacteria is strongly adaptable in obtaining both carbon and nitrogen from varying environments.

Key words: endophytic diazotrophs, diversity, eletrophoresis of whole cell protein patterns, fingerprinting patterns, clustering analysis