Abstract

The antifungal potential of hydro-ethanolic leaf extracts of bean varieties was analyzed by bioautography, assessing the contribution of defense molecules of proteic nature against two bean fungal pathogens Colletotricum lindemuthianum and Phaeoisariopsis griseola, also, the Rf values and relative activities of separated compounds were determined; these compounds were in a range of medium polarity to high polarity. The bioactivity expressed by the studied bean varieties could be correlated with the presence of proteic nature compounds, in joint action with secondary plant metabolites. There was some similarity in the chemical composition of the components of the extracts. The varieties G18350, G14241, G1320 CIAT and Vigna ungiculata were the most promising for isolating antifungal compounds. The results demonstrate the value of bioautography as a simple and cheap method to examine plant extracts with antifungal activity.

Key words: Phaseolus vulgaris L, Vigna unguiculata (L.) Walp, bioautography, peptides, secondary metabolites, Colletotricum lindemuthianum, Phaeoisariopsis griseola, antifungal defense.

Abbreviation

Abbreviations: MTT, Methyl thiazolyl tetrazolium; C. l,  Colletotricum lindemuthianum; P. g,  Phaeoisariopsis griseola; PDA, potato dextrose agar; CIAT, International Center for Tropical Agriculture.