Native microbial consortia improve maize shoot and root systems at early developmental stages in a seedbed assay

Abstract

Background: Agriculture is a major contributor to environmental and soil degradation. Soil microorganisms are essential to improve plant growth, crop yields and stress-tolerance.
 Objective: To characterize maize early plant-response in a seedbed setting to native consortia of isolated microorganisms from arid zones.
 Methods: Sixteen fungal and 16 bacterial isolates from arid soils were identified by MALDI-TOF MS and confirmed using morphological characteristics. Ten biofertilizers were tested in replicates (n=100) in maize under seedbed conditions. Consortia were formulated based on growth promoting traits, including mainly Penicillium and Pseudomonas species. After 45 days, biofertilizers were evaluated according to plant height, and shoot and root fresh weight.
 Results and Conclusions: Penicillium and Pseudomonas were the predominant genera identified. Most strains are potential candidates for biofertilizer formulation based on their growth promoting traits. Bacterial consortia mainly promoted plant caulinar development, while the combination of fungal and bacterial species markedly increased root development. Eight biofertilizer consortia from arid zones had positive effects at early developmental stage of maize under seedbed conditions compared to uninoculated plants.

Identification and Characterization of Beneficial Soil Microbial Strains for the Formulation of Biofertilizers Based on Native Plant Growth-Promoting Microorganisms Isolated from Northern Mexico

“…Therefore, in this study, different croplands and wild plant species were sampled to increase the diversity of the isolated microorganisms. In addition, an arid climate was chosen since plants growing in arid and semiarid regions are exposed to harsh environmental stresses, including soil nutrient scarcity, water deficiency, high temperature, and solar radiation, and can survive, to a large extent, due to their association with beneficial microorganisms which are genetically and metabolically adapted to grow in these conditions and can help host plants to maintain homeostatic balance [ 7 , 12 , 13 ].…”

“…Proper identification and characterization of microorganisms is also important when formulating microbial consortia [ 4 , 6 , 13 ]. The microorganisms in an inoculum can develop several types of interactions (e.g., synergy or competition) depending on factors such as microbial diversity, environmental conditions, and culture medium [ 3 , 11 , 13 ].…”

“…Proper identification and characterization of microorganisms is also important when formulating microbial consortia [ 4 , 6 , 13 ]. The microorganisms in an inoculum can develop several types of interactions (e.g., synergy or competition) depending on factors such as microbial diversity, environmental conditions, and culture medium [ 3 , 11 , 13 ]. There are several cases in which microbial identification would help to understand the dynamics of these interactions, for example, when (1) certain combinations of microorganisms promote the dominance of certain species and suppress the growth of others, (2) members with greater taxonomic proximity share resource requirements favoring their cultivation, (3) different microbial genera develop complementary cross-feeding functions in which the secreted metabolites of one species function as a substrate for others, (4) the release of signaling molecules from certain species help shape population density and behavior, or when (5) certain microorganisms alter environmental conditions (pH, oxygen content, viscosity) that influence the growth and development of the consortium [ 2 , 3 , 4 , 5 , 11 , 13 ].…”

“…Beneficial soil microorganisms can be isolated, characterized, identified, and propagated to be used in agriculture as biofertilizers. It is important to exploit the potential of native microorganisms, as several authors indicate that the efficiency of biofertilizers is higher when native strains isolated from the rhizosphere are used [ 11 , 12 , 13 ]. Successful biofertilization in the field is achieved with high colonization rates.…”

“…Successful biofertilization in the field is achieved with high colonization rates. It has been reported that indigenous microbial strains are more efficient in colonizing plant roots than laboratory or commercial strains; since root colonization and plant–microbial interactions are induced by the root and seed exudates, native microbial strains could be metabolically and genetically adapted to develop those processes [ 11 , 13 , 14 ].…”