REACTION OF DIFFERENT GENOTYPES OF NARANJILA OR TREE TOMATO (Solanum quitoense) TO FUSARIUM oxysporum ATTACK

Related to sanitary aspect of green orange (Solanum quitoense) crop in the department of Narino; yellowish and wilt by vascular and radical rot caused by Fusarium oxisporum are registered like the most limiting diseases. The present research was stated due to the increase of the disease incidence and the lack of efficient management techniques. In order to test the reaction of different green orange genotypes inoculated with pathogen to find resistance or tolerance sources to this disease. Field trips were done in northern producer areas of the Narino department to collect some affected tissue samples from symptomatic plants, and, to obtain seeds proceeding from healthy plants in commercial plots which were attacked by Fusarium sp. This way 25 - Castilla variety genotypes were collected and tested more 12 materials from Doctor Tulio Cesar Lagos' collection (University of Narino). Four - different colony of this fungus was isolated in the laboratory. At first the pink colony was used because it is the typical fungus colony, and, besides it was isolated in a higher quantity from affected tissue collected in field. This colony was used to inoculate, through the injection method in the stem base every material obtained and grown in greenhouse conditions. Those plants which remained healthy, were inoculated again to test their reaction. Finally, in those surviving genotypes, the virulence of remaining isolations of this fungus was studied by same method. It was determined that genotypes related to Solanum sessiliflorum, Solanum hirtum and Solanum marginatum species showed to be resistant to the pathogen inoculation since no symptoms of this disease were presents in any of the evaluations.