Actividad fitotóxica del filtrado crudo de colletotrichum gloeosporioides en cardamomo (elettaria cardamomum)

Abstract

Colletotrichum gloeosporioides is one of the most important phytopatogen fungi specie in the world, especially in the tropical and subtropical regions. In Colombia it is the causal agent of antracnosis in cardamom plants. Different experiments were done in order to evaluate the phytotoxic activity of the crude filtrate on cardamom leaves and vitroplants, and also to demonstrate the presence of phytotoxic compounds which are involved in the patogenical process. It was evaluated, on cardamom leaves, the phytotoxic activity of the crude filtrate that was obtained from the culture of four C. gloeosporioides isolations. These cultures were done under different growth conditions (light day vs. darkness and agitated culture at 110r.p.m. vs. non agitated cultures) and under different fermentation periods (7, 14, 21, 28 days). It was observed a major phytotoxic activity in cultures that grew up under light day conditions and with a fermentation period superior to 21 days. The filtrate phytotoxicity compounds thermostability was evaluated at different temperatures (25°C, 40°C, 100°C and 120ºC) and it was found that these components kept their phytotoxic activity even after being exposed to such temperatures. It was demonstrated the existence of phytotoxic activity of the filtrate on vitroplants when two groups of 150 plants (seedling) each were exposed to concentrations of it of 50% and 90% respectively; damage and mortality of these vitroplant in comparison with the control (vitroplants) were shown and found.