Eficiencia simbiótica de hongos micorrízicos arbusculares (HMA) en el botón de oro (Tithonia diversifolia)

La presente investigación tuvo como objetivo evaluar el efecto de tres cepas de Hongos Micorrízicos Arbusculares (HMA) sobre el crecimiento, producción de biomasa, y colonización micorrízica en plántulas del botón de oro(Tithonia diversifolia). Mediante un Diseño Completamente Aleatorizado (DCA) se estudiaron cuatro tratamientos (el control y la inoculación de las tres cepas de HMA (Claroideoglomus claroideum, Scutellospora calospora Claroideoglomus etunicatun) con diez unidades experimentales por tratamiento. La inoculación micorrízica se realizó por el método de inmersión de la raíz, antes de trasplantar las plántulas en macetas con tierra estéril. Durante treinta días, las plantas se regaron con 100 ml de agua del grifo cada 3 días y se suministró cada cuatro días una solución nutriente (5 ml por maceta de solución de Hoagland) a 1 cm de la raíz. Los resultados evidenciaron mayor altura, producción de biomasa y porcentaje de colonización micorrízica en las plántulas que fueron inoculadas con cepas de Claroideoglomus etunicatun (T3) y Scutellospora calospora(T2); en comparación al control y las plántulas del T1, inoculadas con cepas de Claroideoglomus claroideum.

Selection and valorization of arbuscular mycorrhizal fungi isolated from phosphate sludge basins in promoting of citrus and carob seedlings

Accumulation of phosphate sludge (PS) generated from phosphate treatment process in the open air represent an environment risk and a problem in terms of storage capacities. The use of this by-products in agriculture, is an alternative recovery technique for the phosphate. Moreover, selection of symbionts and their inoculation into the soil whether in the nursery or at field were strongly encouraged. These inoculants were selected not only for their impact on the plant, but also for their ability to persist in the soil at the expense of the residual native microflora. This can be performed to the microorganisms which could occur in the solid sludges deriving the exploitation of phosphates in a pilot site of Khouribga area. In this context, the indigenous mycorrhizal resources have been exploited through better exploration of the local floristic diversity and then a series of mycorrhizal fungi selection and production tests have been made. The mycorrhizal complex was prepared and their effect was tested in Citrus and carob plants growth in the nursery. Two mixtures of PS were carried out: 10% (S2) and 40% (S5) for Citrus plants and 20% (S3) and 40% (S5) for carob plants. The sandy soil of Maamora forest was used as a control (S1). The results shown three dominant morphotypes were detected: Rhizophagus irregularis, Funnileformis constrictum and Scutellospora calospora. The effect of the PS with the AMF-based inoculum indicate that mycorrhizal inoculation of the substrates by a raw inoculum stimulates the growth of plants specially S2, S5 and S3 for Citrus volkameriana, Carrizo citrange and carob respectively. Based on these results, this combination between PS and mycorrhizal fungi had a great effect on Citrus and carob plant in the nursery.

Enhancing plant quality and outplanting growth of Acacia auriculiformis in dry wasteland plantations by inoculating a selected microbial consortium in the nursery

In this study, the performance of a selected microbial consortium (Scutellospora calospora + Azotobacter chroococcum + Bacillus coagulans + Trichoderma harzianum) on Acacia auriculiformis A. Cunn. ex Benth. was evaluated through large-scale nursery trials at three locations in the Mandya district of Karnataka state, India. At each location, 500 inoculated and 500 uninoculated seedlings were cultivated. The increase in plant dry biomass of inoculated plants was 31% (mean of three locations) compared with uninoculated plants. The seedlings inoculated with microbial consortium under large-scale nursery trials were planted in wasteland at three locations, and their growth was monitored for nearly 6 years. At the end of the study, field growth of inoculated trees, measured as the biovolume index, was 52% higher than that of uninoculated trees. This study shows that the selected microbial consortium enhances nursery quality and midterm field growth of Acacia auriculiformis plantations on dry wasteland.

Morphological and Structural Diversities of Indigenous Mycorrhiza Communities Associated to Castor Bean from Adamawa Cameroon

This study describes the diversity of arbuscular mycorrhizal fungi (AMF) that enter into association with castor bean growth wild in Subsaharan Africa. Three sites of castor bean stands were selected in each of the three Subdivisions (Ngaoundere I, Ngaoundere II and Nyambaka) of the Vina Division in Adamawa Cameroon. Soil samples and roots were taken from each castor bean rhizosphere. All samples from one site were mixed into a composite sample. Leek was used as trap plant. Mycorrhizal parameters, spores density and specific richness were determined following to the standard methods. After spore extraction, species identification was obtained through the informations provided by the International Vesicular Mycorrhizal fungi collection. Results indicate that Cameroonian castor bean accession was found to be symbiotic with AMF under Sudano-Guinean climate of Adamawa Cameroon. The morphological and structural characterization enabled the description of six AMF species, belonging to three genera: Glomus fasciculatum, Glomus sp1, Glomus sp2, Scutellospora calospora, Scutellospora purpurasens, Entrophospora infrequens. These findings open opportunities for domestication and application of AMF for a sustainable castor bean productivity.

Selection of arbuscular mycorrhizal fungi for sugarcane in four soils with the presence of dark septate endophytes

The present study aimed to select efficient arbuscular mycorrhizal fungi (AMF) for sugarcane growth and P nutrition in four soils that spontaneously contained dark septate endophytes (DSE). The effect of nine AMF isolates was evaluated individually in sugarcane presprouted seedlings (SP81-3250) grown under greenhouse conditions for a 120-day period. The isolates that stimulated plant growth in the soils with low P availability were Acaulospora colombiana (ACOL), Claroideoglomus etunicatum (CETU), Gigaspora margarita (GMAR), Rhizophagus clarus (RCLA) and Scutellospora calospora (SCAL). Compared to the Yellow Argisol, which had the highest P level, the Red-Yellow Argisol, with an intermediate P content, increased plant height. Compared to the other treatments, inoculation with ACOL, RCLA, and SCAL resulted in higher foliar P content in plants grown in soils with high to intermediate P levels. Root colonization by AMF and DSE was verified in the plants, with the coexistence of both fungal groups in the same plant and/or root fragment. However, AMF colonization was low compared to DSE colonization. The cooccurrence of DSE and AMF was higher in the plants inoculated with ACOL, RCLA, SCAL, and Dentiscutata heterogama. ACOL, CETU, GMAR, RCLA, and SCAL are AMF isolates that have the potential to establish a mycorrhizal inoculant for sugarcane that would be effective in several soils.

Arbuscular mycorrhizal fungus influence maize root growth and architecture in rock phosphate amended tropical soil

Hemos ensayado la influencia del homgo micorrícizo arbuscular (AM) Scutellospora calospora en la estructura, crecimiento, asimilación de nutrientes, actividad fosfatasa y dependencia micorrizal de raíces de maíz por adicción de 0-5% de fosforita (RP) en suelos deficientes de fósforo (P). La adicción de RP aumentó significativamente la longitud total de la raíz, el número de raíces a diferentes niveles y el diámetro de los pelos radiculares de las plantas AM. El hongo AM influyó positivamente el crecimiento del maíz y la asimilación de nutrientes. Las actividades fosfatasa ácida y alcalina fueron mayores en las plantas AM en suelos mejorados. Al aumentar las concentraciones RP se redujeron no linealmente el porcentaje de colonización del hongo AM. Entonces, la inoculación de hongos AM junto a la mejora de fósfoso proveniente de RP podría sustituir fertilizantes químicos y hacer disponible el P proveniente de RP. We evaluated the influence of arbuscular mycorrhizal (AM) fungus Scutellospora calospora on root architecture, growth, nutrient uptake, root phosphatase activity and mycorrhizal dependency of maize in 0-5% rock phosphate (RP) amended phosphorus (P) deficient soil. RP amendment significantly increased total root length, number of roots in different orders, and root hair diameter of AM plants. The AM fungus positively influenced maize growth and nutrient uptake. Acid and alkaline phosphatase activities were higher for AM plants in RP amended soils. In contrast, increasing concentrations of RP reduced the percentage of AM fungus colonization non-linearly. Thus, AM fungus inoculation along with RP amendment could substitute chemical fertilizers and make available the P in RP to the plants.

Biochemical changes in Tomato plant by AM fungi

The effectiveness of six arbuscular mycorrhizae species, Acaulospora morrowae Spain & Schenck, Gigaspora margarita Becker & Hall, Glomus fasciculatum (Thaxt. Sensu. Gerd.) Gerd. & Trappe, G. macrocarpum Tul. & Tul. Scutellospora calospora (Nicol. & Gerd.) Walker & Sanders, and Sclerocystis rubiformis Gerd. & Trappe, collected from rhizosphere soils of Tomato, was measured for enrichment of PRO, PPO activities and protein, phenolic, and catechin contents in this vegetable plant. Culturing was done under green house and studied were performed ninety days after inoculation. All fungi showed favorable effects, with S. calospora being the most promoting of all biochemical parameters.

Efecto de micorrizas nativas y fósforo en los rendimientos del maíz en Guárico, Venezuela

En suelos de sabana del estado Guárico – Venezuela, se evaluó la eficiencia de cuatro especies de hongos formadores de micorrizas nativa y su mezcla: Scutellospora pellucida, Scutellospora calospora, Glomus leptotichum y Acaulospora mellea en la toma de N y P, y su efecto en los rendimientos del cultivo de maíz hibrido HIMECA 3005 con 4 dosis de P (0, 27, 54 y 80 kg ha-1 de P2O5). Se sembró a 0,9 m entre hileras y 0,4 m entre plantas, la cuantificación del P y N foliar se hizo muestreando la hoja opuesta a la mazorca, por los métodos de Murphy – Riley y destilación con Kjeldalh; los redimientos se evaluaron en los tres surcos centrales de cada parcela. Se utilizó un diseño de bloques al azar con arregló factorial. Encontrándose que las dosis de P y los morfotipos evaluados influyeron en la toma de N y P, siendo 54 kg ha-1 de P2O5 y la mezcla de inóculos los de mejor eficiencia para la toma de N; mientras que la dosis de 54 kg ha-1 de P2O5 más Scutellospora pellucida para la toma de P. Se concluyó que estos inóculos pueden disminuir la aplicacion de P en un 25% e incrementar los rendimientos del maíz hasta en un 100% (de 2 a 4 t ha-1 ) con base en la producción de la zona.Palabras clave: Micorrizas, suelos de sabana, absorción de nutrientes.

Morphological identification of vesicular-arbuscular mycorrhiza on bulbous plants (Taurus mountain in Turkey)

This study was conducted to investigate the morphological identification of vesicular-arbuscular mycorrhiza (VAM) on bulbous plants in the Taurus Mountains in Turkey. Thirteen soil samples and bulbous roots were taken from the rhizosphere of bulbous plants. The soils were analyzed for the number of VAM spores and chemical and physical properties. In addition, the roots were examined for infection levels, and morphological identification of VAM spores was made. All tested plants are considered mycorrhizal plants. We determined three spore species (Glomus mosseae, Glomus hoi and Scutellospora calospora) from the surveyed soils. The spore distribution rates were as follows: G. Mossea 61.54 %, G. Hoi 23.07 % and Scutellospora calospora 15.38 %. Results suggest that VAM fungal spores and root colonization display variation in rhizosphere under bulbous plants in different ecological conditions.

Fungos micorrízicos arbusculares afetando a produção de mudas de pinhão-manso na região sul do Estado de Tocantins, Brasil

O presente trabalho teve como objetivo avaliar os efeitos da inoculação de quatro espécies de fungos micorrízicos arbusculares no crescimento e nutrição de mudas de pinhão-manso. Foram utilizados 12 tratamentos e 10 repetições, sendo: a inoculação individual (Scutellospora calospora, Glomus clarum, Gigaspora margarita, Acaulospora morrowiae), em dupla das espécies (S. calospora + G. clarum, S. calospora + G. margarita, S. calospora + A. morrowiae, G. clarum + G. margarita, G. clarum + A. morrowiae e G. margarita + A. morrowiae), com a mistura das quatro espécies de micorrizas (MIX) e a testemunha sem inoculação com micorrizas. Para os teores de macro e micronutrientes, 75 dias após a emergência das plantas, diferenças significativas (p < 0,05) foram observadas para os teores de nitrogênio (N), fósforo (P), potássio (K), magnésio (Mg), enxofre (S), manganês (Mn) e boro (B), com destaque para a inoculação com G. clarum e A. morrowiae isoladamente e em dupla inoculação. Para a biomassa da parte aérea e raiz, colonização micorrízica e eficiência micorrízica, as maiores médias (p > 0,005) foram observadas para os tratamentos com G. clarum e A. morrowiae inoculados isoladamente e para a dupla inoculação de S. calospora + G. clarum e G. clarum + A. morrowiae.