Characterization of native plant growth-promoting bacteria (PGPB) and their effect on the development of maize (Zea Mays L.)

Abstract

Maize (Zea mays L.) is one of the most important cereals for Mexico and humanity. The Yaqui Valley -located in the northwest of Mexico- is one of the most important agricultural regions worldwide, it is characterized by an indiscriminate use of inorganic fertilizers for improving crop yields, leading to an increased environmental and economic cost of maize production. Here, a morphological, metabolic, and molecular characterization of native bacteria associated with maize rhizosphere was carried out, and then positive effects of bacterial inoculation to plants under greenhouse conditions were evaluated. The evaluated strains were taxonomically affiliated –based on the 16S rRNA gene- as Bacillus sp. (13B41), Advenella incenata (22A67), Pantoea dispersa (22B45), and Rhizobium pusense (31B11). All of these strains were able to synthesize indoles, produce siderophores, and solubilize phosphates. The individual inoculation of these strains to maize plants showed a significant increment (compared to un-inoculated plants) in height (35-40 %), shoot dry weight (244-289 %), root dry weight (99-137 %), and SPAD values (40- 47 %). The native bacteria associated with maize in the Yaqui Valley are a promising alternative to promote the growth of their host plant, and contribute to a sustainable maize production.