Determinación mediante aislamiento y purificación de hongos potencialmente micorrízicos en las raíces de seis especies de orquídeas en el cantón Gualaceo, provincia del Azuay

Abstract

The symbiotic relationship between fungus and orchid’s roots is of great importance for the nutrition and germination of these plants. Although mycorrhizal fungi occur almost everywhere in the world, human activities such as deforestation and agricultural frontier expansion, can result in soils or substrates lacking a beneficial fungipopulation or decreased fungi abundance. In the absence or deficiency of these mycorrhizal fungi, the plants growth could be inadequate. The aimof this research was to isolate and purify potentially mycorrhizal fungi present in roots of six native orchids species of Canton Gualaceo, province of Azuay. The sampling was performed in july and august 2016, in the Remigio Crespo Toral parish(Gulag) at the banks of the San Francisco River, 2.525 meters above the sea level (m.a.s.l). The orchids species used in this work were: Pleurothallis angustipetala, Elleanthus oliganthus, Trichoceros anteniferum, Oncidium aureum, Pleurothallis gramínea, Epidendrum secundum. Sample processing and subsequent colonies isolation was performed following the methodology proposed by Zettler (2013).Ten root fragments were collected, which length varied between 5 – 10 cm. The sampling was performed in duplicate. It was possible to isolate and purify six potentially mycorrhizal fungi belonging to the genus Tulasnella. The highest percentage of these kinf of fungi were isolated from roots belonging to the species Pleurothallis angustipetala, Pleurothallis gramínea and Epidendrum secundum. The identification of the isolated fungiwill be confirmed by the amplification and sequencing of specific DNA regions, which is the next step in the project "Study of the symbiotic orchid-mycorrhiza relationship in the province of Azuay, Ecuador” carried out in the orchid garden of the University of Cuenca.