Orchids are known for their vast diversity and dependency on mycorrhizal fungi. Under in situ conditions, the biotic and abiotic factors determining the composition and distribution of orchid mycorrhizal fungi (OMF) communities remain largely unexplored. Therefore in situ experiments are needed to better understand the interactions between orchids and fungi. A seedling-trap experiment was conducted in the Reserva Biológica San Francisco, a well-known biodiversity hotspot located in the Andes of southern Ecuador. The objective was to investigate the effect of orchid species, site, elevation or temporal variation on the assembly and structure of OMF associated with Cyrtochilum retusum and Epidendrum macrum. The OMF community composition was determined using the Illumina MiSeq sequencing of the internal transcribed spacer 2 (ITS2) region. The results exhibited 83 OMF operational taxonomic units belonging to Tulasnellaceae, Ceratobasidiaceae, Serendipitaceae and Atractiellales. It was observed that the composition of the OMF communities was different among orchid species and temporal variation but was not different among sites. The results further support that orchids have a core of keystone OMF that are ubiquitously distributed and stable across temporal change, whereas the majority of these fungi are randomly associated with the plants.

In natural environments, it has been shown that orchids interact with multiple microorganisms including various species of fungi that colonize their tissues. The diversity of these fungi associated with orchid roots is still being described along with the ecological role they play when interacting with the orchids. In this study, we evaluated the richness and diversity of the endophytic and mycorrhizal fungi associated with the roots of Maxillaria acuminata, a common epiphytic orchid species from a tropical montane forest in southern Ecuador. We characterized the fungal communities by sequencing the ITS2 region of the nrDNA with Illumina MiSeq technology. In total, 843 fungal OTUs were uncovered using a 97% sequence similarity. The highest percentage of OTUs belonged to the Agaricomycetes class, Basidiomycota. Interestingly, the most frequent trophic guild from the analyzed OTUs was assigned as saprophytic. Also, some groups of orchid mycorrhizal-forming fungi were detected, including members within the families Ceratobasidicaceae, Serendipitaceae, Tulasnellaceae, and in the order Atractiellales. We discuss the potential influence of this diverse group of root-associated endophytic fungi on the development and survival of M. acuminata in the tropical forests of southern Ecuador.

El banano es la fruta tropical de mayor consumo mundial. Su producción es un importante ingreso económico en países de Latinoamérica y el Caribe. Recientemente, el cultivo de banano se ha visto afectado por el ataque de patógenos muy agresivos como Fusarium oxysporum y Mycosphaerella fijiensis. El control químico es una estrategia ampliamente utilizada, que ha llevado al uso excesivo de agroquímicos en la producción bananera. Existe una gran preocupación mundial por el estado de los cultivos de banano, siendo necesario encontrar alternativas amigables con el medio ambiente. Ecuador es uno de los principales productores de banano en el mundo, por lo que es fundamental innovar el sistema de producción mediante la implementación de alternativas biológicamente sostenibles para minimizar el impacto ambiental y garantizar la productividad. La presente revisión pretende consolidar información clave sobre los hongos asociados al banano, incluyendo técnicas de aislamiento e introducción de endófitos. Finalmente, se incluyen investigaciones relevantes sobre estrategias biotecnológicas basadas en hongos endofíticos y micorrízicos para mejorar la producción de banano. Nuestro objetivo es que esta revisión proporcione información para la investigación experimental en el diseño de inoculantes fúngicos.

Vanilla is an orchid of great economic and cultural value. In Ecuador, Vanilla tahitensis and V. planifolia are cultivated as introduced species, while V. odorata is native to the Amazon. In several areas, production depends on wild populations, which threatens ecosystems and the conservation of germplasm. In vitro propagation offers a sustainable alternative. This study evaluated the in vitro introduction and propagation of V. odorata (from Tena) and V. tahitensis (from Santo Domingo) from seeds. V. odorata did not respond to the disinfection treatments, whereas V. tahitensis showed high germination and development in 50% MS medium supplemented with specific additives and a disinfection protocol using water, alcohol, and chlorine with Tween 20. Seedlings were acclimatized in a substrate composed of moss, perlite, and compost. The in vitro culture of V. tahitensis demonstrates potential for mass production, while V. odorata requires specific disinfection protocols.