Isolation and chemical and biological characterization of phytotoxins produced by phytopathogenic fungi of agrarian crops

Phytopathogenic fungi are the first determinants in infectious diseases of crop plants, playing an important role not only in causing devastating epidemies but also through the persistent and significant annual crop losses with consequent heavy economic problems. Considering the social and economic impact of the plant diseases, many efforts have been made to avoid losses in agrarian production. Thus, the study of phytotoxins and the knowledge of plant pathogenesis processes can help to find the best and rapid remedial to control plant diseases. The aim of this PhD project has been the investigation of phytotoxins isolated from agrarian crops pathogens. Phytotoxic fungal culture filtrates were obtained from Ascochyta lentis var. lathyri and Ascochyta lentis, responsible for Ascochyta blight on grasspea and lentil respectively, Colletotrichum lupini, the etiological agent of antrachnose of lupin, and Neofusicoccum batangarum the causal agent of “scabby cankers” of cactus pear. Phytotoxic cultures have been extracted and the corrisponding phytotoxic extracts have been purified to obtain phytotoxic metabolites by bio-guided chromatographic processes.