Efectividad de hongos micorrízicos arbusculares nativos de rizósfera de Agave como promotores de crecimiento de papaya

Los hongos formadores de micorriza arbuscular (HMA) son simbiontes benéficos de la mayoría de las plantas terrestres. La planta involucrada en la simbiosis es aprovisionada de nutrimentos por parte del hongo que promueve el crecimiento vegetal, a cambio de energía para reproducción del HMA. Se evaluó la efectividad de inóculos multi-específicos de HMA provenientes de la rizosfera de Agave cupreata colectada en Michoacán México, en la promoción del crecimiento de plantas de papaya. Se realizó un experimento en diez bloques al azar con once tratamientos: ocho consorcios de HMA, un biofertilizante comercial a base de HMA (EndoMic®), una cepa de referencia (Claroideoglomus claroideum) y un testigo sin HMA. A 100 d posteriores al establecimiento del experimento, las variables evaluadas fueron altura de planta, diámetro del tallo, biomasa seca del follaje, de la raíz y total, área foliar, índice relativo de dependencia micorrízica, colonización micorrízica y densidad de esporas micorrízicas. Los datos fueron analizados mediante un análisis de varianza y de correlación. Los resultados mostraron que dos de los consorcios promovieron eficientemente el crecimiento vegetal; las plantas inoculadas con los consorcios AD-MTu y CM-MT incrementaron significativamente (Tukey, P ≤ 0.05) su crecimiento en biomasa seca con respecto al testigo sin HMA, en 240 y 225%, respectivamente, mientras que con el biofertilizante EndoMic® el aumento para la misma variable fue de solo 12%. Se concluye que el empleo de consorcios de HMA promueven el crecimiento de papaya; y por tanto, podrían emplearse en vivero o invernadero

Diversidad de Glomeromycota en especies silvestres de Agave en Tlacolula, Oaxaca

Instituto Politécnico Nacional CIIDIR Oaxac

Riqueza de especies de hongos micorrízicos asociados a plantas de la familia Euphorbiaceae en el Área Natural Protegida Altas Cumbres, Tamaulipas, México

The arbuscular mycorrhizal fungi (AMF) are important for the development and survival of plants. This has motivated the analysis of the use of some AMF species with commercial use as crop biofertilizers at the national level. In Tamaulipas, knowledge of AMF diversity is scarce. The objective of this work was to determine the presence and taxonomic identity of AMF associated with the Euphorbiaceae family (sensu lato) in the Altas Cumbres Protected Area. The spores were obtained through propagules extracted from trap plants of different species grown in the soil and roots of the area under study. The mycorrhizal status was determined by the Phillips and Hayman staining technique and the identification of AMF through the extraction of spores by the wet sieving method with sucrose centrifugation and their morphological characterization. All the roots showed typical AMF structures, evidencing the presence of this association in the 74 euphorbiaceae taxa. A rich-ness of 9 AMF species located within 6 genera, 4 families and 3 orders were recorded, with Glomus (Glomeraceae famiy) being the genus with the highest specific richness. The presence of the genera Entrophospora, Funneliformis and Rhizophagus was detected for the first time in Tamaulipas. The results denote how widely distributed AMF are found in plants of the Euphorbiaceae family in the Altas Cumbres Protected Area, highlighting the need to continue with investigations on arbuscular mycorrhizae.Los hongos micorrízicos arbusculares (HMA) son importantes para el desarrollo y supervivencia de las plantas. Esto ha motivado el análisis del uso de algunas especies de HMA de uso comercial como biofertilizantes de cultivos a nivel nacional. En Tamaulipas, el conocimiento acerca de la diversidad de HMA es escaso. El objetivo del presente trabajo fue determinar la presencia e identidad taxonómica de hongos micorrízicos arbusculares asociados a la familia Euphorbiaceae (sensu lato) en el Área Natural Protegida Altas Cumbres. Las esporas fueron obtenidas a través de propágulos extraídos de plantas trampa de diferentes especies, cultivadas en suelo y raíces de la zona de estudio. El estatus micorrízico se determinó mediante la técnica de tinción de Phillips y Hayman y la identificación de HMA, a través de la extracción de esporas por el método de tamizado húmedo con centrifugación con sacarosa, y su caracterización morfológica. Todas las raíces mostraron estructuras típicas de los HMA, evidenciando la presencia de esta asociación en los 74 taxones de euforbiáceas. Se registró una riqueza de 9 especies de HMA ubicadas dentro de 6 géneros, 4 familias y 3 órdenes, siendo Glomus (Familia Glomeraceae) el género con mayor riqueza específica. Se detectó la presencia de los géneros Entrophospora, Funneliformis y Rhizophagus por primera vez en Tamaulipas. Los resultados denotan lo ampliamente distribuidos que se encuentran los HMA en las plantas de la familia Euphorbiaceae en el Área Natural Protegida Altas Cumbres y la necesidad e importancia de continuar con investigaciones sobre las micorrizas arbusculares

Arbuscular Mycorrhizal Fungi Associated with Maize (<i>Zea mays</i> L.) in the Formation and Stability of Aggregates in Two Types of Soil

Knowledge of native Arbuscular Mycorrhizal Fungi (AMF) and their relationship with the edaphic characteristics where they live is important to establish the influence of allochthonous AMF, which were inoculated, on the development and stability of soil aggregates. The objectives of this research were to know the composition of native AMF species from two contrasting soils, and to establish the development and stability of aggregates in those soils with corn plants after inoculating them with allochthonous AMF. The experiment had three factors: Soil (two levels [S1 and S2]), HMA (three levels: without application [A0], with the application of Claroideoglomus claroideum [A1] and with the application of a consortium [A2]) and Fertilization (two levels (without fertilization [f0] and with fertilization [f1])). Twelve treatments were generated, with five replicates (60 experimental units [EU]). The EU consisted of a pot with a corn plant and the distribution was completely random. The results demonstrated that the Typic Ustifluvent presented nine species of native AMF, while the Typic Dystrustert had three; the native AMF in each soil influenced the activity of allochthonous AMF, such as their colonization and sporulation. Likewise, differences were found in the stability of macro-sized aggregates (0.5 to 2.0 mm)

Physiological Responses of Agave maximiliana to Inoculation with Autochthonous and Allochthonous Arbuscular Mycorrhizal Fungi

The benefits of mycorrhizal interactions are only known in 8 of 210 recognized Agave taxa. We evaluated the effects of autochthonous and allochthonous arbuscular mycorrhizal fungi (AMF) on growth and nutrient assimilation in Agave maximiliana. The autochthonous consortium (Cn) of eight species was propagated from the rhizospheric soil of A. maximiliana, while Claroideoglomus claroideum (Cc) and Claroideoglomus etunicatum (Ce) were employed as allochthonous AMF. Six treatments were included in the study: Cn, Ce, Cc, Ce + Cc, Tf (fertilized control), and Tn (non-fertilized control, not inoculated). Mycorrhizal colonization increased over time, and the colonization percentages produced by Cn and the allochthonous AMF, both alone and mixed together, were equal at 6, 12, and 18 months. Height increased steadily and was higher in AMF-treated plants from seven months onward. Growth indicators of AMF-treated and AMF-free plants were equal at 6 months, but the beneficial effects of allochthonous and autochthonous AMF were evident in all growth indicators at 18 months and in sugar and mineral (P, K, Ca, Mg, and Fe) content. Arbuscular mycorrhizal fungi significantly improved all growth parameters of A. maximiliana regardless of the origin of the inoculums. This is the first study to report the positive effects of AMF colonization in A. maximiliana

Impact of Crude Oil on Functional Groups of Culturable Bacteria and Colonization of Symbiotic Microorganisms in the <i>Clitoria-Brachiaria</i> Rhizosphere Grown in Mesocosms

This research evaluated the changes on populations of culturable N-fixing free bacteria (NFFB) and P-solubilizing bacteria (PSB), as well as on the root nodulation by native rhizobia, the root colonization and spore number of arbuscular mycorrhizal fungi (AMF), in the rhizosphere of Clitoria ternatea and Brachiaria brizantha grown in mesocosms contaminated with crude oil (0, 3000, 6000, 9000, and 12000 mg kg-1), for 240 days. After 24 h of soil contamination, the highest populations of NFFB and PSB (5.5 and 4.9 LogUFC, respectively) were found in control, and the lowest populations were obtained at 12000 mg kg-1 (5.1 and 4.2 LogUFC, respectively). In contrast, at 60 and 240 days, the control showed lower populations of NFFB and PSB (5.4 and 4.8 LogUFC, respectively) than contaminated treatments. The highest number or root nodules in C. ternatea was quantified in control at 60 and 240 days (25 and 27 nodules, respectively) in comparison to those observed at the treatment with 12000 mg kg-1 (7 and 1 nodule, respectively). At 60 days, AMF colonization in both plant species, and the number of spores significantly decreased as the crude oil concentration increased; however, at 240 days, the highest number of AMF spores was recorded at treatments with 6000 and 12000 mg kg-1. The dry weight of both plant species significantly decreased as crude oil concentrations increased. Although C. ternatea was more susceptible to the toxic effects of crude oil, this plant species showed greater content of total chlorophyll than B. brizantha

Role of Estrogens in the Size of Neuronal Somata of Paravaginal Ganglia in Ovariectomized Rabbits

We aimed to determine the role of estrogens in modulating the size of neuronal somata of paravaginal ganglia. Rabbits were allocated into control (C), ovariectomized (OVX), and OVX treated with estradiol benzoate (OVX + EB) groups to evaluate the neuronal soma area; total serum estradiol (E2) and testosterone (T) levels; the percentage of immunoreactive (ir) neurons anti-aromatase, anti-estrogen receptor (ERα, ERβ) and anti-androgen receptor (AR); the intensity of the immunostaining anti-glial cell line-derived neurotrophic factor (GDNF) and the GDNF family receptor alpha type 1 (GFRα1); and the number of satellite glial cells (SGCs) per neuron. There was a decrease in the neuronal soma size for the OVX group, which was associated with low T, high percentages of aromatase-ir and neuritic AR-ir neurons, and a strong immunostaining anti-GDNF and anti-GFRα1. The decrease in the neuronal soma size was prevented by the EB treatment that increased the E2 without affecting the T levels. Moreover, there was a high percentage of neuritic AR-ir neurons, a strong GDNF immunostaining in the SGC, and an increase in the SGCs per neuron. Present findings show that estrogens modulate the soma size of neurons of the paravaginal ganglia, likely involving the participation of the SGC

Investigación educativa en las aulas de primaria

Reúne trabajos derivados de la experiencias de diversos docentes en educación primaria en los siguientes temas: Tecnología de Información y Comunicación, educación inclusiva, enseñanza de la música, educación física, enseñanza de la historia, acoso escolar, auto-evaluación, métodos de enseñanza, inteligencia emocional, percepción del alumno, marco cognitivo en comprensión lectora y comunicación escuela-familia