Griselda Chávez-Aguilar

Excessive nitrogen (N) fertilization in maize (Zea mays L.) production causes environmental degradation, particularly in semi-arid regions where high chemical inputs are necessary to maintain crop production. Plant growth-promoting rhizobacteria (PGPR) could reduce the optimal N fertilization doses. This investigation aimed to isolate bacteria, screen them for plant growth-promoting traits, and evaluate their potential effects on maize grain under different chemical N fertilization doses. Isolates Stenotrophomonas maltophilia LIMN and Enterobacter roggenkampii LCMG demonstrated multifunctional growth-promoting traits in vitro, including N₂ fixation, indole-3-acetic acid and siderophore production, potassium solubilization, and desiccation tolerance, with E. roggenkampii LCMG also solubilizing inorganic phosphate. A field trial across four chemical N fertilization rates (0, 40, 80, and 120 kg N ha⁻¹) revealed that single bacterial inoculation without N fertilizer matched or exceeded uninoculated controls receiving up to 80 kg of N ha⁻¹ (the standard recommendation). Specifically, S. maltophilia LIMN combined with the recommended rate of 80 kg N ha⁻¹ achieved the maximum grain yield (4601.2 kg DM ha⁻¹), outperforming uninoculated controls (without PGPR) receiving excessive fertilization at 120 kg N ha⁻¹ (3760.4 DM ha⁻¹). Although maize plants benefited from inoculation with S. maltophilia LIMN or E. roggenkampii LCMG, achieving similar or better yields than crops fertilized with high chemical N inputs under stress factors such as deficiency of moisture, low-nutrient soils, and high temperatures, the present study did not test the pathogenicity and biosecurity of S. maltophilia or E. roggenkampii in crops; therefore, the results are not a direct recommendation of their use as biofertilizers before novel studies to assess all the limitations and the potential to reduce N dependency in order to design novel sustainable strategies for crop production.

The present study aimed to determine the Genotype × Environment interaction (GEI), yield stability, and agronomic performance of 24 “Pinto” bean lines under semi-arid conditions in Central-West Mexico. All the lines possess a slow-darkening seed coat, a trait that prolongs visual quality and increases market value. The lines, which exhibit an indeterminate prostrate growth habit, were evaluated in three contrasting environments: irrigated, rainfed, and drought-stressed. A combined analysis of variance, Tukey’s test, and the additive main effects and multiplicative interaction (AMMI 2) model were applied to assess seed yield and agronomic traits. Average seed yield declined markedly across environments, from 2279 kg ha⁻¹ under irrigation to 593 kg ha⁻¹ under drought stress, with different lines performing best in each environment. AMMI 2 biplot analysis showed that the first two principal components explained 100% of GEI variability for seed yield, dry shoot biomass, total biomass, harvest index, pods per plant, and seeds per pod. Both genetic and environmental effects were significant, with notable GEI patterns. Despite pronounced environmental influence, several lines exhibited stable performance across environments. Line 11 consistently combined high yield and stability, positioning it as a strong candidate for cultivar registration and as a parent in breeding programs targeting semiarid regions. These results underscore the importance of multi-environment evaluation for identifying genotypes with broad or specific adaptation, contributing to genetic improvement and sustainable bean production under variable moisture regimes.

The formulation and evaluation of microbial consortia remain key challenges in developing sustainable agricultural technologies. This study assessed the potential of microbial consortia to promote early-stage maize growth using a rapid and efficient in vitro approach. Four germination methods were compared to identify the most suitable for evaluating fungal effects. The compatibility of fungal strains with previously isolated bacteria and yeasts was analyzed to formulate consortia based on mutual compatibility. The selected method was used to evaluate consortium efficacy, and the functional mechanisms of the most effective combination were characterized. The between-paper germination system proved optimal for plant growth promotion (PGP) studies with fungi, as it produced handleable seedlings displaying architecture closely resembling field-grown plants. Thirteen treatments were developed from compatible strain combinations. Among them, the tripartite consortium composed of Aureobasidium sp. VFRB, Clavispora sp. Y35, and Pantoea sp. CanP2-19b significantly enhanced germination rates, seedling architecture, and biomass accumulation. Functionally, the fungus mobilized nutrients and produced siderophores; the yeast exhibited high indole production; and the bacterium effectively solubilized phosphorus and potassium. These results highlight the agrobiotechnological potential of this consortium for use in technologies that improve maize establishment. Additionally, the study underscores the value of germination assays as essential tools in the bioprospecting of plant growth-promoting microorganisms, contributing to the advancement of sustainable agriculture. https://doi.org/10.21929/abanicomicrobiano/2025.1 Clave: 2025-1 https://www.youtube.com/watch?v=RburpuJrCng La formulación y evaluación de consorcios microbianos representa un reto clave para el desarrollo de tecnologías agrícolas sostenibles. Este estudio evaluó la capacidad de consorcios microbianos para promover el crecimiento de maíz en etapas tempranas mediante una metodología in vitro rápida y eficiente. Se compararon cuatro métodos de germinación para identificar el más adecuado para evaluar el efecto de microorganismos fúngicos. Se evaluó la compatibilidad de las cepas fúngicas con bacterias y levaduras previamente aisladas para conformar consorcios por compatibilidad. Mediante el método seleccionado se evaluó la eficacia de los consorcios y se caracterizaron los mecanismos de acción del consorcio sobresaliente. El sistema de germinación en rollos de papel fue ideal para estudios de promoción de crecimiento vegetal (PCV) con hongos al obtener plántulas manipulables con arquitectura similar a las germinadas en condiciones naturales. Se obtuvieron trece consorcios de las combinaciones compatibles. El consorcio tripartito: Aureobasidium sp. VFRB, Clavispora sp. Y35 y Pantoea sp. CanP2-19b mejoró significativamente la tasa de germinación, la arquitectura de las plantas y la acumulación de biomasa. A nivel funcional, el hongo mostró capacidad para movilizar nutrientes y producir sideróforos; la levadura una alta producción de indoles, y la bacteria habilidad para solubilizar fósforo y potasio. Estos hallazgos respaldan el potencial agrobiotecnológico del consorcio para su integración en tecnologías orientadas a optimizar el establecimiento del cultivo de maíz. Asimismo, el estudio destaca la utilidad de los ensayos de germinación como herramientas clave en la bioprospección de microorganismos PCV, aportando información relevante para el desarrollo de prácticas agrícolas sostenibles. https://doi.org/10.21929/abanicomicrobiano/2025.1 Clave: 2025-1 https://www.youtube.com/watch?v=RburpuJrCng https://doi.org/10.21929/abanicomicrobiano/2025.1 Clave: 2025-1 https://www.youtube.com/watch?v=RburpuJrCng

Agroecological alternatives for the integrated management of recurrent pests in Mexican lime (Citrus aurantifolia); as well as to establish possible synergies with the commercial bioinsecticide. Design/methodology/approach: This experiment was conducted in two phases: 1) visual monitoring and pre-identification of pests and fungal diseases in the Mexican lime crop, and 2) application and evaluation of the effect of application of commercial bioinsecticide (Biocanela) and mineral broths (bordeaux broth and sulfocalcium broth) alone and mixtures. Results: The pests with highest incidence were thrips (Pezothrips kellynus), Asian citrus psyllid (Diaphorina citri), whitefly (Bemisia tabaci), fruit fly (Drosophila melanogaster), and red spider mite (Tetranychus urticae), while the main fungal diseases were sooty mold (Capnodium citri), red algae (Cephaleuros virescens), citrus greasy spot (Mycosphaerella citri), and anthracnose (Colletotrichum acutatum). The mixture of mineral broths with the bioinsecticide Biocanela showed the highest fungicide and insecticide activity, and repellency on various pests and diseases of the Mexican lemon crop. Limitations on study/implications: Generate scientific knowledge regarding to the best agroecological alternatives for the integrated management of citrus pests and diseases that are economically and environmentally profitable. Findings/conclusions: Application of the mixture of sulfocalcium broth and Biocanela showed repellency effectiveness against pests such as thrips (Pezothrips kellyanus), Asian citrus psyllid (Diaphorina citri), whitefly (Bemisia tabaci), and fruit fly (Drosophila melanogaster). Likewise, it was effective against sooty mold (Capnodium citri), red algae (Cephaleuros virescens), and citrus greasy spot (Mycosphaerella citri), while the effect was lighter against anthracnose (Colletotrichum acutatum). Additionally, it induces new, healthy shoots in Mexican lemon trees.

Objective: To evaluate the effects of the general combining ability (GCA) and the specific combining ability (SCA) on the agronomic variables of piquin pepper (Capsicum annuum var. Glabriusculum) genotypes. Methodology: A total of 36 F1 and nine parental crosses were used as plant material. The genotypes were distributed in a completely randomized block design with three replications. Ten agronomic variables were evaluated. Results: Differences (P≤ 0.01) were found in all the evaluated variables, both in the genotypes and in GCA and SCA. Additive gene action influenced heritability, where following variables stood out: days to harvest (DTH), chlorophyll (CHL), plant height (PH), average fruit weight (AFW), fruit equatorial diameter (FED), and fruit polar diameter (FPD). One the one hand, genotypes G6 and G7 recorded the highest positive yield values for GCA, with 143.96 and 66.97 kg ha-1, respectively. On the other hand, 58% of the SCA crosses obtained favorable yield results. Meanwhile, the highest positive values were obtained by the G6xG7, G8xG9, G5xG9, G3xG4, G4xG8, and G1xG8 crosses, which recorded 427.1, 190.5, 167.4, 146.8, 129.7, and 125.7 kg ha-1, respectively. Conclusions: According to the effects of GCA and SCA on the agronomic variables of piquin pepper, the genotypes G6 and G7 can be used to develop varieties, while the G6xG7, G8xG9, and G5xG9 crosses are recommended for hybrid formation within breeding programs.

Introducción: El manejo forestal sustentable se enfoca en la obtención de servicios ambientales, a la par que se mantiene la acumulación de biomasa aérea (BA).Objetivo: Estimar la BA a lo largo de una cronosecuencia de bosque templado y examinar el papel del manejo forestal para la producción maderable sobre los patrones de fijación, incremento y asignación de BA.Materiales y métodos: Se seleccionó una cronosecuencia de rodales dominados por Pinus patula Schiede ex Schltdl. & Cham. en un rango de 7 a 30 años. La BA se estimó con modelos alométricos y parametrizados para inferir la edad a la cual el bosque manejado alcanza su producción máxima. Se calculó la producción de BA, la productividad primaria neta aérea (PPNA), los incrementos en BA y su asignación a los componentes estructurales de los árboles, los cuales se compararon con los de un área natural sin manejo forestal (BSM).Resultados y discusión: La BA y PPNA aumentaron con la edad del rodal a lo largo de la cronosecuencia. El rodal de 30 años presentó 79 % de la BA contenida en el BSM. Estos dos sitios tuvieron una producción alta de BA, la cual correspondió a una PNNA elevada con 87 % de similitud. El fuste fue el componente estructural con mayor asignación de BA (70 %), debido principalmente a las prácticas silviculturales como el aclareo, que forma parte del programa de manejo forestal.Conclusion: Los bosques de P. patula con manejo forestal aceleraron la acumulación de BA en rodales de bosques templados a lo largo de la cronosecuencia estudiada, alcanzando niveles similares a los de un BSM en un periodo más corto.

Conocer la estructura y composición de un bosque permite entender los atributos dasométricos de los árboles y los procesos ecosistémicos a lo largo de gradientes de vegetación derivados de la altitud. Se analizó la estructura del bosque de Pinus hartwegii en un gradiente de 600 m, en el Nevado de Toluca. Se establecieron conglomerados de 1 ha en cada altitud; se registraron variables dasométricas. La estructura vertical y horizontal se evaluó con la densidad arbórea (DA), área basal (AB) y parámetros e índices estructurales. Estos últimos mostraron que P. hartwegii mantienen su abundancia y dominancia a lo largo del gradiente altitudinal estudiado, principalmente de los 3 700 a 4 000 m, donde forma bosques monoespecíficos. La contribución en la estructura arbórea disminuyó de 100 % a 3 900 y 4 000 m, a 45 % en los 3 500 m. Los parámetros dasométricos indicaron mayor DA en individuos de clases diamétricas de 5-15 cm, fue superior por debajo de los 3 800 m; ello evidenció que la regeneración puede ser más limitada a grandes altitudes, posiblemente debido a una extracción irregular del arbolado. Se concluye, que la composición estructural del bosque de P. hartwegii presenta un cambio importante en su estructura de acuerdo con la altitud, lo que resultaría de la interacción ambiente-sociedad mediante la gestión del uso del suelo asociada a la altitud, que compromete la estructura y función del ecosistema. Se recomienda incorporar la altitud como una variable determinante en planes de manejo para bosques de alta montaña.

The present review examines the factors and variables that should be considered to obtain, design, and evaluate EFEs that might enhance ruminal NDF degradability. Different combinations of words were introduced in Google Scholar, then scientific articles were examined and included if the reported factors and variables addressed the objective of this review. One-hundred-and-sixteen articles were included. The fungal strains and culture media used to grow white-rot fungi induced the production of specific isoforms of cellulases and xylanases; therefore, EFE products for ruminant feed applications should be obtained in cultures that include the high-fibrous forages used in the diets of those animals. Additionally, the temperature, pH, osmolarity conditions, and EFE synergisms and interactions with ruminal microbiota and endogenous fibrolytic enzymes should be considered. More consistent results have been observed in studies that correlate the cellulase-to-xylanase ratio with ruminant productive behavior. EFE protection (immobilization) allows researchers to obtain enzymatic products that may act under ruminal pH and temperature conditions. It is possible to generate multi-enzyme cocktails that act at different times, re-associate enzymes, and simulate natural protective structures such as cellulosomes. Some EFEs could consistently improve ruminal NDF degradability if we consider fungal cultures and ruminal environmental conditions variables, and include biotechnological tools that might be useful to design novel enzymatic products.

Objective: To analyze the genetic diversity (agronomic attributes, forage yield, and fiber content) of 100 maize inbred lines and to identify genotypes with potential for the breeding of plants with the said traits. Design/methodology/approach: One-hundred maize inbred lines were evaluated in two environments, in a 10 x 10 complete block experimental design, with two repetitions. Days to male flowering, days to female flowering, ear height, plant height, stem diameter, green forage yield, neutral detergent fiber, and acid detergent fiber data were recorded. Results: Significant differences were observed in the environmental sources of variation and genotypes for all the traits evaluated. The first four components account for 81% of the total variation observed and the first two account for 66% of the variation. The variables which have the highest absolute value and which strongly influence the dispersion of the genotypes, as well as the formation of groups, were: plant height, forage yield, and acid detergent fiber (component one) and days to female flowering and days to male flowering (component two). Consequently, the genotypes were dispersed in four groups. Study limitations/implications: It was not possible to conduct genetic diversity studies using molecular markers. Findings/conclusions: The grouping pattern of inbred lines shows the genetic diversity present; this can be an important tool in genetic improvement programs aimed at obtaining hybrids with specific characteristics.

La acumulación y distribución de biomasa hacia los componentes estructurales de los árboles es determinante en bosques manejados, tanto en términos de productividad maderable como en la reactivación de diversos procesos ecosistémicos. En el presente estudio se analizó el patrón de acumulación de biomasa aérea total (BAT) y su asignación hacia fuste, ramas, corteza y follaje en una cronosecuencia de un bosque de Pinus patula bajo aprovechamiento forestal en Zacualtipán, Hidalgo. Mediante el uso de ecuaciones alométricas se estimó la BAT y por componente estructural de los árboles en rodales con diferentes años después de la cosecha, en diferentes años de remedición (años 2005, 2008 y 2012). Se encontró que la BAT aumentó con el tiempo después de la cosecha, con diferencias estadísticas significativas (p < 0.0001) entre los rodales. El rodal de 30 años después de la cosecha presentó una biomasa aérea total (BAT) de 178.1 Mg ha^-1, la cual resultó solo 20% menor a la observada en el rodal sin cosecha (AN), lo que indica que un bosque bajo aprovechamiento podría alcanzar niveles de biomasa aérea similares a la del AN, en un menor tiempo. La asignación de biomasa aérea (BA) presentó el siguiente orden: fuste> ramas> corteza> follaje. Esta asignación de BA fue favorecida hacia fuste como un producto maderable comercial, objetivo principal de estos bosques bajo producción. El patrón de asignación de BA entre los componentes estructurales de los árboles puede ser incorporado como base para el diseño de prácticas silvicuturales en los programas de manejo forestal y contribuir en la evaluación de la sustentabilidad de los bosques. Además, puede clarificar el papel de los bosques regenerados después de los aprovechamientos en la fijación y almacenamiento de bióxido de carbono atmosférico.