Evaluación de la resistencia genética de especies de Passiflora spp A Fusarium spp, agente causal de la “Secadera”

Abstract

El maracuyá amarillo Passiflora edulis Sims var flavicarpa Degener, representa un renglón importante en la fruticultura colombiana, por su aceptación en el mercado nacional y por su potencial de exportación. El departamento del Valle del Cauca es considerado como el de mayor participación en la producción nacional de esta fruta, a pesar que los cultivos presentan alta incidencia de una enfermedad vascular conocida como secadera, causado por el hongo Fusarium oxysporum f. sp. passiflorae.

//Abstract: The yellow passion fruit Passiflora edulis Sims var flavicarpa Degener, it’s an important asset for Colombian fruit, for its acceptance in the domestic market and export potential. The department of Valle del Cauca is considered the largest share in domestic production of this fruit, though the crops have high incidence of vascular disease, known as dry wilt caused by the fungus Fusarium oxysporum f. sp. passiflorae. A solution to this problem is the use of resistant rootstocks to control fungal pathogens and prevent soil loss in the passion fruit, therefore species of Passiflora that are resistant or tolerant should be sought. Thus Corpoica keeps Passifloras genebank Research Center La Selva, including some species with commercial potential, which express a remarkable genetic variability, interspecific and intraspecific. From this bank 28 introductions species were selected belonging to 17 Passifloras to assess resistance to Fusarium oxysporum f. sp. passiflorae causing passion fruit dry wilt. These introductions will be a study of genetic diversity, to determine the phylogenetic distance between selected species. To evaluate the selected Passifloras, two methods were tested to inoculate, cut the stem and the roots immersion. Insulation was used most pathogenic (MUC5) obtained in previous studies. 13 Fusarium fungi were isolated, they were obtained from the stem and the root of plants affected with symptoms of dry wilt of passion fruit in five municipalities in the department of Valle del Cauca. After obtaining the isolated they were identified morphologically and molecularly. This study found that 13 isolated belong to the genus Fusarium, these isolated were grouped in four species: F. verticillioides, Fusarium oxysporum, Fusarium brachygibbosum, and Fusarium solani, it was also found that inter and intraspecies differences.