Tropical soils withstand heavy pressure due to deforestation as a result of the change in land use, decreasing their quality. Traditionally, the quality of soil has been based on physical and chemical indicators; however, the biological ones can predict variations in the quality, in an early and effective way. In this research, the microbiological quality of soils from two ecosystems was evaluated, one from the Cumbaza Sub-Basin (CSB) and the other from Degraded Pastures at Cuñumbuque (DPC), both in San Martín, Peru. The physicochemical characteristics were studied and the microbial populations of Total Bacteria (TB), Sporulated Bacteria (SB), Total Fungi (TF), Actinobacteria (ACT), and parameters of microbial activity such as Basal Respiration (BR), Microbial Biomass (MB), Metabolic Quotient (qCO2) and Microbial Quotient (qMIC). According to the Principal Component Analysis (PCA), the...

Tropical soils withstand heavy pressure due to deforestation as a result of the change in land use, decreasing their quality. Traditionally, the quality of soil has been based on physical and chemical indicators; however, the biological ones can predict variations in the quality, in an early and effective way. In this research, the microbiological quality of soils from two ecosystems was evaluated, one from the Cumbaza Sub-Basin (CSB) and the other from Degraded Pastures at Cuñumbuque (DPC), both in San Martín, Peru. The physicochemical characteristics were studied and the microbial populations of Total Bacteria (TB), Sporulated Bacteria (SB), Total Fungi (TF), Actinobacteria (ACT), and parameters of microbial activity such as Basal Respiration (BR), Microbial Biomass (MB), Metabolic Quotient (qCO2) and Microbial Quotient (qMIC). According to the Principal Component Analysis (PCA), the...

El objetivo del presente estudio fue aislar y seleccionar bacterias endofíticas de arroz capaces de inhibir al fitopatógeno Burkholderia glumae THT, así como caracterizarlas por su genética y bioquímica. También se buscó caracterizar la diversidad genética y los factores de virulencia presentes en cepas de B. glumae y de Burkholderia gladioli, otro patógeno de arroz, aisladas de campo. Se colectaron plantas de arroz en 4 departamentos del norte de Perú, y tras la desinfección de tejidos se aislaron bacterias endofíticas por cultivo en agar soya tripticasa (30 °C; 48 h) y en medio selectivo (pH 4,5; 41 °C; 72 h). Se evaluó la actividad antimicrobiana frente a B. glumae THT, la producción de sideróforos y la resistencia a la toxoflavina, toxina producida por este agente. La identificación molecular se realizó mediante BOX-PCR y secuenciación del gen 16S ARNr. Además, s...

El arroz es el cereal más importante para más del 50% de la población mundial, sin embargo las enfermedades pueden limitar su producción. El añublo bacterial de la panícula, es una de las enfermedades con mayor vigilancia en el cultivo de arroz, debido a los cambios climáticos que exacerban su incidencia. El agente etiológico de la enfermedad, se atribuye a Burkholderia glumae y Burkholderia gladioli. El presente estudio, tuvo como objetivo seleccionar controladores biológicos contra B. glumae THT, a partir de la microbiota endofítica del cultivo de arroz. Para ello, se realizaron colectas de 7 cultivares de arroz en los departamentos de Tumbes, Piura, Amazonas y San Martín. Las muestras de arroz fueron procesadas para aislamiento de grupos funcionales asociados a control biológico (Bacillus, Pseudomonas y Burkholderia). Las cepas de bacterias endofíticas fueron seleccionada...

La investigación tuvo como objetivo aislar el micelio secundario de Auricularia spp y Pleurotus spp procedente de tres áreas naturales de la región San Martín, así como evaluar el crecimiento en medio agar papa dextrosa y en sustratos estériles a base de residuos agroindustriales. Se obtuvieron 10 aislamientos de micelios secundarios a través de carpóforos desinfectados de Pleurotus spp y otros 10 aislamientos de carpóforos desinfectados de Auricularia spp. La mayor velocidad de crecimiento en Auricularia spp fue de 62,5 µm h-1 (A1) y de 75 µm h-1 (B10) para Pleurotus spp. En una segunda parte del experimento se produjo semilla de las cepas nativas más veloces en granos de maíz esterilizado durante un periodo de incubación de 40 días. La semilla fue inoculada en sustratos estériles a base de residuos agroindustriales. Las cepas A1 de Auricularia spp y B10 de Pleurotus spp...

La investigación tuvo como objetivo aislar el micelio secundario de Auricularia spp y Pleurotus spp procedente de tres áreas naturales de la región San Martín, así como evaluar el crecimiento en medio agar papa dextrosa y en sustratos estériles a base de residuos agroindustriales. Se obtuvieron 10 aislamientos de micelios secundarios a través de carpóforos desinfectados de Pleurotus spp y otros 10 aislamientos de carpóforos desinfectados de Auricularia spp. La mayor velocidad de crecimiento en Auricularia spp fue de 62,5 µm h-1 (A1) y de 75 µm h-1 (B10) para Pleurotus spp. En una segunda parte del experimento se produjo semilla de las cepas nativas más veloces en granos de maíz esterilizado durante un periodo de incubación de 40 días. La semilla fue inoculada en sustratos estériles a base de residuos agroindustriales. Las cepas A1 de Auricularia spp y B10 de Pleurotus spp...

Arbuscular mycorrhizal fungi (AMF) are organisms that form mutualistic associations with most plants, favoring their development, especially those located in degraded areas. In order to identify the different predominant native AMF morphotypes, and determine the percentage of colonization, and spore density in soils of the Cumbaza sub-basin in San Martin, Peru, soil samples were taken from degraded areas of Chirikyacu, Vista Alegre, El Chontal, San Antonio de Cumbaza, Aucaloma and Shapumba, and they were associated with 4 legumes cover crops among them, Cajanus cajan, Canavalia ensiformis, Crotalaria juncea and Vigna unguiculata. A completely random design was used, considering 6 zones and 4 legumes with 3 replications. The results showed that the treatments with legumes had greater influence in the mycorrhizal colonization in comparison with the zones of study, being Vigna unguiculata t...

Arbuscular mycorrhizal fungi (AMF) are organisms that form mutualistic associations with most plants, favoring their development, especially those located in degraded areas. In order to identify the different predominant native AMF morphotypes, and determine the percentage of colonization, and spore density in soils of the Cumbaza sub-basin in San Martin, Peru, soil samples were taken from degraded areas of Chirikyacu, Vista Alegre, El Chontal, San Antonio de Cumbaza, Aucaloma and Shapumba, and they were associated with 4 legumes cover crops among them, Cajanus cajan, Canavalia ensiformis, Crotalaria juncea and Vigna unguiculata. A completely random design was used, considering 6 zones and 4 legumes with 3 replications. The results showed that the treatments with legumes had greater influence in the mycorrhizal colonization in comparison with the zones of study, being Vigna unguiculata t...

In the present investigation was able to authenticate the ability to nodulate and to evaluate the frequency of nodulation efficiency of 50 isolate strains of pea nodules, collected from the departments: La Libertad, Lambayeque, Cajamarca and Lima. Which was inoculated to 1 mL of culture suspension alone (1.2x109 cel /mL) in seedlings of Pisum sativum var. Selection Junín, keeping them under conditions of relative humidity,50-70% and temperature / photoperiod, 28 °C – 24 °C / 14 h – 10 h (light-dark). At 25 days post-inoculation was obtained that 40% nodulated the host plant. To determine the frequency of nodulation efficiency, we took into account the parameters of speed of nodulation (DN in mm) and the percentage of roots nodulated (PRN%); pearson correlational analysis of the 5% significance, MANOVA and Tukey statistical DHS, allowed to establish the ranges (high, medium and low...

En la presente investigación se logró autenticar la capacidad nodulativa y evaluar la frecuencia de la eficiencia en la nodulación de 50 cultivos aislados de nódulos radiculares de arveja, colectados de los Departamentos: La Libertad, Lambayeque, Cajamarca y Lima. Para lo cual se inoculó 1mL de suspensión del cultivo aislado (1,2x109 cel / mL) en plántulas de Pisum sativum var. Selección Junín, manteniéndolas bajo condiciones de humedad relativa, 50–70% y temperatura/fotoperiodo, 28 °C - 24 °C / 14 h – 10 h (luz-oscuridad). A los 25 días post-inoculación se obtuvo que el 40% nodularon a la planta huésped. Para determinar la frecuencia en la eficiencia de nodulación, se tuvo en cuenta los parámetros de velocidad de nodulación (DN en mm) y el porcentaje de raíces noduladas (PRN%); el análisis Correlacional de Pearson al 5% de significancia, el MANOVA y el estadísti...

In the present investigation was able to authenticate the ability to nodulate and to evaluate the frequency of nodulation efficiency of 50 isolate strains of pea nodules, collected from the departments: La Libertad, Lambayeque, Cajamarca and Lima. Which was inoculated to 1 mL of culture suspension alone (1.2x109 cel /mL) in seedlings of Pisum sativum var. Selection Junín, keeping them under conditions of relative humidity,50-70% and temperature / photoperiod, 28 °C – 24 °C / 14 h – 10 h (light-dark). At 25 days post-inoculation was obtained that 40% nodulated the host plant. To determine the frequency of nodulation efficiency, we took into account the parameters of speed of nodulation (DN in mm) and the percentage of roots nodulated (PRN%); pearson correlational analysis of the 5% significance, MANOVA and Tukey statistical DHS, allowed to establish the ranges (high, medium and low...

Rice feeds more than 50% of the population worldwide, representing a great energy contribution in low-income families. The exaggerated use of synthetic chemical fertilizers to maintain high levels of yield causes alterations in the physical, chemical and biological quality of the soils. A sustainable alternative is the use of beneficial microorganisms that promote plant growth in crops. The objective of the study was to isolate and evaluate the Plant Growth Promoting (PGP) traits of rhizospheric rice bacteria in soils of the San Martin region, evaluate the effect of promoting growth in rice under pot experiments conditions and finally evaluate the effect of selected strains on the yield under different doses of nitrogen fertilizer under field conditions. Initially, 27 strains were selected for their diazotrophic characteristics and characterized by PGP traits. Through a multivariate anal...