Tesis de maestría
Efecto del extracto de jatropha dioica sessé en el control de fusarium oxysporum en tomate (solanum lycopersicum l.)
Autor
Salas Gómez, Alma Leticia
Resumen
"El cultivo de tomate (Lycopersicum esculentum L.) es la segunda hortaliza de mayor importancia en el mercado mundial. México ocupa el segundo lugar en producción de tomate, siendo Sinaloa el estado con mayor producción. Esta hortaliza se ve afectada por diferentes enfermedades causadas por virus, bacterias, insectos y hongos. Una de las principales enfermedades que presenta el tomate es producida por Fusarium oxysporum, una alternativa de bajo costo para el control de esta enfermedad son los extractos de plantas, ya que por su naturaleza evitan el deterioro ambiental y no afectan la productividad y calidad de los alimentos. Los tallos y rizomas de Jatropha dioica Sessé ex Carv. (Sangre de drago) contienen componentes fenólicos que le confieren una actividad biológica importante como antifúngico. El objetivo del presente estudio fue evaluar el efecto del extracto de los tallos de J. dioica en el desarrollo de F. oxysporum f. sp. lycopersici en plantas de tomate en invernadero.
Los tallos de las plantas de J. dioica se colectaron en el sitio de Rocamontes, Coahuila, México. El extracto de J. dioica (EJD) se obtuvo de los tallos mediante una solución etanol-agua (25:75). Se prepararon las macetas de plástico con una mezcla de perlita-peat moss-suelo esterilizado (33:33:33). El experimento se estableció en el invernadero bajo un diseño completamente al azar con 8 tratamientos y 10 repeticiones: T1: Testigo absoluto; T2: Testigo inoculado; T3: 100ppm EJD; T4: 300 ppm EJD; T5: 500 ppm EJD; T6: 1000 ppm EJD; T7: 2000 ppm EJD y T8: 3000 ppm EJD. Las plántulas de T2 a T8 fueron inoculadas antes del trasplante con una solución de 1.7X10 6 esporas ml-1. Los extractos de J. dioica fueron aplicados a las plántulas en el trasplante y en 3 ocasiones posteriores (a los 10, 20 y 40 días después del trasplante). El riego y la fertilización se realizaron de acuerdo a las necesidades de las plantas. Las variables evaluadas fueron: incidencia, severidad, altura de planta y diámetro de tallo (semanalmente) peso fresco de planta completa, peso fresco de hojas, peso fresco de tallo, peso seco total, peso seco de hojas peso seco de tallos, número de nudos y entrenudos; diámetro polar y ecuatorial; firmeza y contenido de sólidos solubles totales y pH de los frutos.
Los resultados del análisis mostraron que el T3 de 100 ppm presentó la mayor inhibición del Fusarium oxysporum teniendo la menor severidad e incidencia en las plantas de tomate, reflejándose esto en mayor altura de planta y diámetro de tallo, demostrando que esta dosis tiene efecto superior contra el patógeno en relación a T1 y al resto de las dosis aplicadas durante el experimento.
El extracto de J. dioica demostró control contra F. oxysporum en tomate a la mas baja concentración probada." "Tomato (Solanum lycopersicum L.) is the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important the world's second most important vegetable vegetable vegetable vegetable vegetable vegetable vegetable in the market. Mexico ranks second in production of this crop where the major cultivated areas are in Sinaloa state. However, this vegetable is strongly affected by diseases caused by viruses, bacteria, insects and fungi. One of the major diseases presented in tomato are produced by Fusarium oxysporum. A low-cost alternative for the control of this plague are the use of plant extracts, since by their nature prevent environmental degradation and do not affect productivity and food quality. Stems and rhizomes of Jatropha dioica Sessé. (Sangre de drago) contain phenolic compounds that could confer significant biological activity as an antifungal.
The aim of the present study was to evaluate the antifungal effect of J. dioica stems and rhizomes extracts against greenhouse-grown tomatoes diseases caused by F. oxysporum f. sp. lycopersici.
J. dioica plants were collected at Rocamontes, Coahuila, Mexico. The extract of J. dioica (EJD) was obtained from stems and rhizomes using an ethanol-water solution (25:75 v/v). Tomato plants cultivation were carried out in plastic pots (4 gallons) containing a mixture of sterilized substrate of perlite-peat moos-soil (weight proportion of 33.3% each). The experiments were carried out in a greenhouse under a completely randomized design with eight treatments and ten replications: T1: absolute control, T2: Witness inoculated; T3: 100ppm EJD; T4: 300 ppm EJD; T5: 500 ppm EJD; T6: 1000 ppm EJD; T7: 2000 ppm EJD and T8: 3000 ppm EJD. Seedlings were inoculated with a solution of 1.7 x 106 spores ml-1. J. dioica extract was applied to transplantation and at 10, 20 and 40 days after transplantation. Irrigation and fertilization were applied according to crop development requirements. The evaluated variables were plant height and stem diameter (weekly), number of fruits per plant, fruit radius (polar length / equatorial diameter), fruits fresh and dry weight, number of leaves per plant, leaves fresh and dry weight, total fresh and dry weight of plant, percentage of dead plants, incidence and severity of the disease per plant, total soluble solids content and fruit pH (at harvest).
The analysis results showed that the application dose of 100 ppm J. dioica extract presented the best performance in terms of stem diameter and height plant, this dose has superior effect against the pathogen in relation to the control and the rest of the doses administered during the experimentation.
J. dioica stems and rhizomes extracts showed disease control of F. oxysporum pathogen in tomato crop, with the highest results observed at the lowest tested concentration (100 ppm)."