Estudio de la fenología y potencial productivo de la Halófita Salicornia bigelovii (Torr.) con la asociación de bacterias fijadoras de nitrógeno

Abstract

The halophyte Salicornia bigelovii is vegetal with high potential to be improved in the sea costs of the northwest in México; however, its productivity depend of the nitrogen aportation, and others macro and micro nutrients essentials. Nitrogen-fixation by bacteria associated to the roots of Salicornia bigelovii and similar halophytes is an important source of available nitrogen in salt marsh ecosystems. However, the diversity of Salicornia’s rhizosphere is unknown. Five areas around the Bay of La Paz in Baja California Sur, Mexico were sampled to detect nitrogen-fixing bacteria associated to this halophyte: where 18 colonies were isolated. Only one showed high acetylene reduction activity. The bacterium was identified as Klebsiella pneumoniae. Effects of K. pneumoniae were evaluated at the germination and early seedling growth stages of two genotypes of S. bigelovii (‘wild genotype’ and cv. ‘SOS-10’). This bacterium, in conjunction with Azospirillum halopraeferens, was tested for growth-promoting ability when inoculated on S. bigelovii genotypes under several saline concentration conditions. During germination and early seedling growth, K. pneumoniae showed high specificity for the wild S. bigelovii genotype, while A. halopraeferens was more specific for the SOS-10 S. bigelovii genotype. On the other hand, the growth and development of the same two genotypes of S. bigelovii, were evaluated under field conditions. When inoculated with previously selected and cultivated native strains of Klebsiella pneumoniae and Azospirillum halopraeferens, these inoculants increased some growth and development parameters, using measures of weight, length of plants, and biochemical characteristics, including total protein, ash, and total lipid content in selected plant parts. The findings suggest that yields of both genotypes of S. vibigelovii, under field conditions, can be improved by the application of K. pneumoniae or A. halopraeferens strains. This is the first report of Klebsiella pneumoniae as nitrogen-fixing bacterium associated to the halophyte Salicornia bigelovii.