espanolSe planteo conocer los generos de hongos formadores de micorriza arbuscular (HMA) asociados a plantaciones de Ochroma pyramidale(balsa) y su nivel de infeccion radicular. Se localizaron y analizaron plantaciones de 1; 2; 3; 4; 5,5; y 7 anos (seis en total) distribuidas en el centro del Tropico Humedo Ecuatoriano (THE). En cada plantacion se delimito tres parcelas de 500 m2, donde a una profundidad de 0 –15 cm se colectaron tres muestras de suelo (aproximadamente 1 kg), y raicillas para estimar el porcentaje de colonizacion radicular.El aislamiento e identificacion de los HMA a nivel de genero y la estimacion de colonizacion micorrizica se realizo mediante la metodologia detamizado, decantacion en humedo con centrifugacion, y despigmentacion –tincion de raices. Se detectaron cuatro generos de HMA: Glomus, Acaulospora, Scutellospora, y Gigaspora, predominando el genero Glomusen todas las plantaciones estudiadas, con poblaciones entre 27 y 169 esporas por 100 gramos de suelo seco (g-1ss), siendo las plantaciones de cuatro anos donde se encontro las mayores poblaciones, mientras que los demas generos mostraron baja representatividad en todas las edades. Se determino baja colonizacion micorrizica radicular en las plantaciones estudiadas, con rangos de 0,28% a 0,65%, porcentajes de colonizacion menores a los reportados para otras especies lenosas en la region. EnglishIt was proposed to know the genera of arbuscular mycorrhizal fungi (AMF) associated withplantations of Ochroma pyramidale(balsa) and their level of root infection. Plantations of 1; 2; 3; 4; 5.5; and 7 years (six in total) were located and analyzed, distributed in the center of the Ecuadorian Humid Tropic (EHT). In each plantation, three 500 m2 plots were delimited, where at a depth of 0-15 cm three soil samples (approximately 1 kg) and rootlets were collected to estimate the percentage of root colonization. The isolation and identification of AMF at the genus level and the estimation of mycorrhizal colonization were carried out using the sieving methodology, wet decantation with centrifugation, and depigmentation -root staining. Four genera of AMF were detected: Glomus, Acaulospora,Scutellospora, and Gigaspora, the Glomusgenus prevailing in all the plantations studied, with populations between 27 and 169 spores per 100 grams of dry soil (g-1ds), being the four-year-old plantations where the largest populations were found, while the other genera showed low representativeness at all ages. Low root mycorrhizal colonization was determined in the plantations studied, with ranges from 0.28% to 0.65%, colonization percentages lower than those reported for other woody species in the region