Biodiv Sci ›› 2011, Vol. 19 ›› Issue (4): 476-484.  DOI: 10.3724/SP.J.1003.2011.09002

Special Issue: 土壤生物与土壤健康

• Original Papers • Previous Articles     Next Articles

Diversity and plant growth promoting activities of the cultivable rhizobacteria of Dongxiang wild rice (Oryza rufipogon)

Fei Luo1,2, Ya Wang2, Qinggui Zeng1, Riming Yan1, Zhibin Zhang1, Du Zhu1,2,*()   

  1. 1 Key Laboratory of Protection and Utilization of Subtropical Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang 330022
    2 Key Laboratory for Research on Active Ingredients in Natural Medicine of Jiangxi Province, Yichun University, Yichun 336000
  • Received:2011-01-12 Accepted:2011-06-09 Online:2011-07-20 Published:2011-07-29
  • Contact: Du Zhu

Abstract:

In order to understand the diversity of cultivable rhizobacteria associated with Dongxiang wild rice at different growth stages and to discover new species and strains of plant growth-promoting rhizobacteria (PGPR), we isolated 118 bacteria strains with different colony morphology using the dilution plate counting method and tested their plant growth promoting activities (PGPA) in May, August and November 2009. Phylogenetic analysis based on partial 16S rRNA sequences indicated that 118 strains clustered into 11 genera, and the dominant bacteria genera were Bacillus, Pantoea and Sphingomonas. The rhizobacteria displayed a high diversity with Shannon-Wiener indices of 2.037-2.741. PGPA analyses indicated that most strains displayed PGPR effects, including nitrogen-fixation, phosphorus-solubilization, IAA-production and siderophore-secretion, and that the dominant PGPR was Pantoea. Additionally, we found that the total amount and PGPA of cultivable rhizobacteria began to increase gradually at seedling stage of Dongxiang wild rice, and reached its peak at heading stage, then decreased at grain filling stage. Our results show that the diversity of bacterial communities in the rhizosphere soil of Dongxiang wild rice is abundant, and that the rich rhizobacteria may be a fascinating PGPR reservoir.

Key words: Oryza rufipogon, rhizosphere bacteria, cultivable bacteria, community diversity, plant growth- promoting activities