Resumo

RUEDA-PUENTE, Edgar O. et al. Bacterial community of rhizosphere associated to the annual halophyte Salicornia bigelovii (Torr.). Terra Latinoam [online]. 2010, vol.28, n.4, pp.345-353. ISSN 2395-8030.

The specie Salicornia bigelovii (Chenopodiaceae) is a halophyte with promising biological and commercial value as a natural resource from arid zones. However, its productivity depends on the nitrogen supply. Nitrogen fixation by bacteria associated with the roots of S. bigelovii is a determinant source of available nitrogen. However, the diversity in Salicomia's rhizosphere is unknown. In order to increase the knowledge of the bacterial diversity associated with the S. bigelovii rhizosphere, polymerase chain reaction (PCR) and single-strand conformation polymorphism (SSCP) analysis was performed. This study was conducted in La Paz, BCS, Mexico. A random sample of 25 S. bigelovii plants at the flowering stage was collected from 6 areas along the coastal line of La Paz Bay in the southern portion of the Baja California Peninsula. DNA extractions of bacterial DNA through amplification (PCR) of the 16S rDNA, SSCP-profiles analysis, isolation of selected bands of SSCP-profiles, cloning, and sequences were carried out. The SSCP technique reflected the bacterial composition evidencing the available diversity and also the dominant populations. The results obtained reflect the presence of Rhizobium spp. and Bacillus spp. This is the first report of these microorganisms associated with S. bigelovii, a novel halophyte crop. Further studies on diversity of the microbial community in the Salicornia bigelovii rhizosphere are required to clarify and describe this ecological association under saline conditions.

Palavras-chave : plant growth-promoting bacteria (PGPB); biofertilizer; soil ecology.