Colombia is among the countries of Latin America that produce about 80% of f ine or “prime” cocoa of the world; however, cocoa in Colombia has limitations related to the presence of cadmium (Cd) in some soils where it is grown and this reduces the safety of the product. The objective of this study was to evaluate the absorption of cadmium in a cocoa pattern (IMC 67) in association with arbuscular mycorrhizal fungi (AMF) to determine their potential use as Cd immobilizers in medium and long-term. A randomized complete block design with three replications and 20 treatments was established, in 4 × 5 factorial arrangement, one control, three types of mycorrhizae (Glomus macrocarpum, Rhizoglomus intraradices and AMF-native) and f ive Cd doses (0, 6, 12, 18 and 24 mg kg-1). Plant height, dry weight of stem, leaves and roots as well as Cd concentration in stems, leaves and roots were measured. The results showed that cacao plants translocate the Cd easily, that is, they can live under these conditions since it was found in all organs (stems, leaves and roots); however, the treatment inoculated with AMF‑native decreased signif icantly the accumulation of Cd in all the organs evaluated. These results conf irm the benef icial effects that AMF have to alleviate the stress that plants shows when translocating heavy metals such as cadmium.

Sugarcane crop for panela production in Colombia presents nutritional limitations especially with the low eff iciency of chemical fertilization. The use of arbuscular mycorrhizal fungi (AMF) optimizes fertilization, making it more eff icient and can reduce the application of synthetic fertilizers. The objective of this study was to evaluate the association of AMF with sugarcane plants for panela production in seedling stage. A characterization of soils was carried out in the regions of Cundinamarca and La Hoya del Río Suárez (Boyacá and Santander), characterized as the main sugarcane for panela production in Colombia and it was found that sugarcane plants establish a natural association with the AMF. The predominant AMF were Glomus microcarpum, Glomus fasciculatum, Glomus sinuosum, four morphotypes of Glomus sp., two of Acaulospora sp. and one of Funneliformis sp. The effect of the inoculation with AMF in the seedling stage was evaluated using three varieties of sugarcane widely cultivated in the Hoya del Río Suárez, CC93-7711 (Pierna Bella), CC93-714 and CC93-7510 (Vende Finca). Eleven (T1 to T8 inoculation with different communities of AMF, T9, T10 and T11 correspond to controls with fertilizations of 10, 50 and 100% of chemical fertilization) were evaluated in a randomized complete block design with three replications. Plant height and stem diameter, spore quantif ication and percentage of colonization were evaluated. The results showed that the three varieties responded to the benef icial effect of the plant-HMA association, f inding plants with higher yield with respect to the non-inoculated plants. The varieties CC93-7711 (Pierna Bella) and CC93-7510 (Vende Finca) showed a higher percentage of AMF colonization in response to the inoculation of Glomus sp.

<p>El objetivo de este estudio fue la obtención de plántulas de tres ecotipos de mora (monterrico, sin espinas y castilla), procedentes de cultivos in vitro inoculados en forma individual y combinada con el Hongo Formador de Micorriza Arbuscular (HFMA) Glomus sp. (GEV02) y las Rizobacterias Promotoras de Crecimiento Vegetal Pseudomonas migulae cepa Pf014 y Bacillus amyloliquefaciens cepa Bs006. Las variables de crecimiento evaluadas fueron longitud aérea y radical (cm), peso fresco y seco foliar y radical (g), así como volumen radical (cm3) y área foliar (cm2). A nivel simbiótico, se midió el porcentaje de colonización por parte del HFMA. Los resultados obtenidos muestran un posible sinergismo entre GEV02 y las rizobacterias evaluadas en forma combinada ya que estas presentaron los mayores valores en todas las variables analizadas. Con el uso de la mezcla de estos microorganismos se observó un mejor establecimiento, desarrollo y vigor de las plántulas de mora en los tres ecotipos considerados y se mejoró su supervivencia (≥80 %) en las etapas de endurecimiento y aclimatación.</p>

ResumoAvaliação de um sistema para micorrização in vitro em plantas de amora-preta (Rubus glaucus, Benth). Objetivo. Obter um sistema de micorrização in vitro em sistemas de cultura autotróficos para plantas de amora-preta (Rubus glaucus, Benth). Materiais e métodos. Foram usados esporos e fragmentos de raízes com vesículas do Fungo Formador Micorrízico Arbuscular (FFMA) Glomus sp. (GEV02). Foi estabelecido um sistema de cultivo autotrófico para mudas de amora-preta, comparando dois métodos de inoculação direta com o FFMA. Foi quantificado o número de esporos produzidos, o comprimento do micélio extra radicular; bem como a porcentagem de colonização do FFMA. Além disso, foi medido o comprimento e o peso fresco e seco da parte folhar e radicular para determinar o desenvolvimento das plantas. Resultados. O sistema de cultivo autotrófico foi bem-sucedido para as plantas de amora-preta (Rubus glaucus, Benth), onde foi observado um crescimento ótimo da parte aérea e da raidicular da planta. Além disso, neste estudo foi obtido um sistema que permitiu o desenvolvimento de Glomus sp (GEV02) sob condições in vitro, com formação de estruturas típicas da simbiose como uma boa colonização intra radicular, com produção de arbúsculos e vesículas, assim como o desenvolvimento de micélio extra radicular com hifas ramificada e a formação de novos esporos. Conclusão. As plantas de amora-preta micropropagadas associaram-se com sucesso, pela primeira vez, com um fungo formador micorrízico arbuscular em condições in vitro, permitindo o desenvolvimento do sistema simbiótico FFMA Glomus sp., associado às raízes das plântulas de amora-preta micropropagadas.Palavras-chave: fungos formadores micorrízicos arbusculares (FFMA), o cultivo autotrófico, Rubus glaucus Benth, Glomus sp (GEV02), micorrização in vitro.

The diversity of arbuscular mycorrhizal fungi (AMF) communities in agricultural systems depends on biotic and abiotic factors as well as on cultural practices. This research aimed to evaluate the diversity of AMF present in an altitudinal transect cultivated with cape gooseberry (Physalis peruviana L.). A set of 13 soil samples from cape gooseberry plantations located in the Colombian Andean mountains in the provinces of Cundinamarca and Boyaca were collected during dry (0-20 mm/month) and rainy (150-330 mm/month) seasons between 1500 and 3000 m a.s.l., in order to establish the relationship between the altitudinal characteristics and AMF diversity. The evaluation of the abundance of spores and species and diversity indexes showed the presence of 46 AMF species in the dry season and 31 in the rainy season. This shows the high diversity of AMF in the tropical Andes with spore abundance between 20 and 120 spores 10 g-1 of soil in the rainy season and between 127 and 1531 spores 10 g-1 of soil in the dry season.