Catastro de hongos endofitos miceliales cultivables en hojas de la hierba marina Thalassia testudinum en Playa Buye, Cabo Rojo, Puerto Rico

Endophytic fungi live inside plant tissues without any external manifestation. As reported previously, they play an important role in the vegetal tissues they inhabit. A study of the fungal endophytes of Thalassia testudinum in Playa Buye, Cabo Rojo, Puerto Rico, was conducted to isolate and identify the cultivable micelial endophytes associated to healthy leaves of this seagrass, which is the most common and abundant in the Caribbean. The plant serves as habitat for marine organisms and as food for marine turtles. Two samplings were performed: one in July and another in December 2004. Leaves were surface sterilized in 0.5% sodium hypochlorite solution and rinsed twice in distilled water. Fragments of the sterilized leaves (apex, center and base) were placed in Marine Agar and incubated for a week at 25°C. Aspergillus fumigatus (38.3%), Curvularia brachyspora (12.8%), Aspergillus flavus (10.6%), Cladosporium oxysporum (10.6%), Fusarium sp. (8.5%), Acremonium sp. (4.3%), Cladosporium sp. (2.1%), Cladosporium cladosporioides (2.1%), Curvularia pallescens (2.1%), Penicillium janthinellum (2.1%), Aspergillus ustus (2.1%), Botrytis sp. (2.1%) and an unidentified morphotype (2.1%) were isolated. This is the first report of micelial endophytes associated to healthy leaves of T. testudinum in Puerto Rico. Aspergillus fumigatus, Aspergillus ustus and Cladosporium oxysporum are reported as endophytes for the first time.