VOLUME 65 : 2017

Eichhornia crassipes infestations and its rapid thick mat formation in freshwater systems has made it as one of the major invasive weeds in the country. In this study, the potential of three fungal isolates as biological control agents for E. crassipes was assessed. Diseased E. crassipes leaves were collected from weed-infested sites in Los Baños, Laguna, and all emergent fungi on potato dextrose agar (PDA) plates were isolated and four were selected for the pathogenicity test following Koch’s postulates. Of the 47 isolates tested, three inflicted necrosis on healthy leaves of E. crassipes and were phenotypically identified as Talaromyces LB018, LB032, and LB033. These three isolates exhibited similar characteristics when grown in both PDA and malt extract agar (MEA) plates. Molecular analysis of the strain LB033 revealed that it is conspecific to strain I5 and almost sequence identical to CBS 286.36 type strain, Talaromyces purpureogenus, based on its molecular data analysis from the internal transcribed spacer (ITS) region. Talaromyces is a genus of fungi in the family Trichocomaceae characterized by having soft, cottony, and loose hyphal fruiting bodies. The anamorphs are strongly similar to Penicillium which is a known biocontrol agent with diverse antagonistic properties against many other microorganisms. The results of this study can provide much-needed information on the potential of Talaromyces as biocontrol agent for E. crassipes

Keywords: biocontrol, Eicchornia crassipes, Talaromyces, Penicillium