Bases para el manejo integrado de hongos fitopatógenos del suelo en el frijol común (Phaseolus vulgaris L.)
Fecha
2014-07-08
Autores
Ramírez López, Miriam
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Editor
Universidad Central "Marta Abreu" de Las Villas
Resumen
Con el objetivo de evaluar el efecto de la testa de semillas de Phaseolus vulgaris
L., y bacterias antagonistas, sobre Rhizoctonia solani, Macrophomina phaseolina y
Sclerotium rolfsii, se determinó la composición química de extractos acuosos
obtenidos de testas de variedades comerciales, mediante tamizaje fitoquímico, y
se cuantificaron los contenidos de fenoles y flavonoides totales. Se evaluó el
efecto in vitro de extractos acuosos de testas y raíces de frijol común sobre el
crecimiento micelial de hongos fitopatógenos del suelo, y el efecto in vitro e in vivo
de bacterias antagonistas sobre el crecimiento de micelial de los hongos
estudiados, y en la reducción de la mortalidad de plantas, en condiciones
semicontroladas, respectivamente. Se encontraron compuestos fenólicos, lo que
estuvo relacionado con el color de la testa de la semilla. Se encontraron
diferencias significativas entre los extractos de la testa de las variedades, en
cuanto al contenido de fenoles totales, con menores valores para el extracto de
testa blanca. El contenido de flavonoides totales, fue superior en el cultivar de
testa roja, mientras que en el de testa blanca no se detectó la presencia de estos
compuestos. Mediante la cromatografía de exclusión molecular las fracciones
obtenidas no mostraron inhibición frente a los hongos fitopatógenos, a diferencias
del extracto acuoso puro. Las bacterias antagonistas inhibieron in vitro el
crecimiento micelial de las especies fitopatógenas estudiadas, e in vivo Macrophomina phaseolina y Rizhoctonia solani fueron las que presentaron mejor
porcentaje de inhibición en cuanto a la reducción de plantas afectadas en la
variedad BAT-482, y T-93 respectivamente además todas las bacterias
estimularon el crecimiento de la parte foliar y radicular de las variedades
estudiadas.
In order to evaluate the effect of the testa of seeds of Phaseolus vulgaris L., and antagonistic bacteria on Rhizoctonia solani, Macrophomina phaseolina and Sclerotium rolfsii, the chemical composition of aqueous extracts from seed coats of commercial varieties was determined by phytochemical screening , and the contents of total phenols and flavonoids were quantified. The in vitro effect of aqueous extracts of seed coats and roots of common bean on mycelial growth of plant pathogenic soil fungi was evaluated, and the in vitro and in vivo antagonistic bacteria on the mycelial growth of the fungi studied effect and the reduction in mortality of plants under controlled conditions, respectively. Phenolic compounds were found, which was associated with the color of the seed coat. Significant differences between the extracts of the seed coat varieties, in the content of total phenols, with lower values for white head extract were found. The total flavonoid content was higher in the red head cultivar, while the white head of the presence of these compounds were not detected. By size exclusion chromatography fractions obtained showed inhibition against phytopathogenic fungi, a pure aqueous extract differences. The in vitro antagonistic bacteria inhibited mycelial growth of phytopathogenic species studied, and in vivo Rizhoctonia solani, Macrophomina phaseolina and were the best presented as percent inhibition of the reduction in affected plants variety BAT-482, and T-93 respectively besides all bacteria stimulated the growth of leaf and root of the varieties studied.
In order to evaluate the effect of the testa of seeds of Phaseolus vulgaris L., and antagonistic bacteria on Rhizoctonia solani, Macrophomina phaseolina and Sclerotium rolfsii, the chemical composition of aqueous extracts from seed coats of commercial varieties was determined by phytochemical screening , and the contents of total phenols and flavonoids were quantified. The in vitro effect of aqueous extracts of seed coats and roots of common bean on mycelial growth of plant pathogenic soil fungi was evaluated, and the in vitro and in vivo antagonistic bacteria on the mycelial growth of the fungi studied effect and the reduction in mortality of plants under controlled conditions, respectively. Phenolic compounds were found, which was associated with the color of the seed coat. Significant differences between the extracts of the seed coat varieties, in the content of total phenols, with lower values for white head extract were found. The total flavonoid content was higher in the red head cultivar, while the white head of the presence of these compounds were not detected. By size exclusion chromatography fractions obtained showed inhibition against phytopathogenic fungi, a pure aqueous extract differences. The in vitro antagonistic bacteria inhibited mycelial growth of phytopathogenic species studied, and in vivo Rizhoctonia solani, Macrophomina phaseolina and were the best presented as percent inhibition of the reduction in affected plants variety BAT-482, and T-93 respectively besides all bacteria stimulated the growth of leaf and root of the varieties studied.
Descripción
Palabras clave
Phaseolus vulgaris L., Extractos vegetales, Hongos del Suelo