ENFERMEDADES FUNGOSAS EN UCHUVA (Physalis peruviana) Y EVALUACIÓN in vitro DE HONGOS ENDÓFITOS CON ACTIVIDAD BIOCONTROLADORA

The cape gooseberry or “uchuva” Physalis peruviana L. is an exotic fruit with export potential, valued for its organoleptic and nutritional characteristics. Most uchuva-producing areas of Colombia are affected by fungal pathogens. Fungicides are applied in excess to control them, leaving traces in the fruit that can cause substantial economic losses. The goal of this study was to isolate and identify fungal pathogens of “uchuva”, and also to isolate (from the same plants) endophytic fungi with biocontrol potential and test them in in vitro antagonism assays. Symptomatic and asymptomatic tissue samples were collected from six farms in Arcabuco-Boyacá, from which eight pathogenic isolates were obtained: three from leaves (Al4H1S, Cl1H1S, Fs1H1S), two from stems (Al2T2S, Fs2T2P), and three from calyces (Al3C1S, Cl2C1P, Fs3C1P). Also, four endophytic fungi were isolated, two from stems (En1T2S = Epicoccum nigrum, En4T2S = Trichoderma citrinoviride) and two from leaves (En2H1S = Myrmaecium rubricosum, En3H2S = Fusarium graminearum). Alternaria spp. was identified as causal agent of black leaf spot, the Cladosporium cladosporioides complex and Alternaria spp. as causal agents of descending drying of the calyx tip, and Fusarium verticillioides as causal agent of vascular wilt, according to Koch's Postulates. Biocontrol tests in vitro used a random design with five repetitions per treatment, and a negative control of the pathogen alone; three endophytic fungi were tested for competition for substrate and antibiosis. Light microscopy showed morphological changes in basic reproductive and somatic structures of the pathogens. All three fungi showed biocontrol activity, but T. citrinoviride was most effective at competition for stubstrate, and M. rubricosum was most effective at antibiosis, judging by inhibition zones.