Diversidad de las comunidades de bacterias y hongos en suelos de cultivos de cacao (Theobroma cacao L.) y café (Coffea arábica) bajo manejo orgánico y convencional

Abstract

Soils are populated by a large number of organisms that develop diverse ecological functions, many of which are important for plant growth and development. Of these species less than 1% have been cultivated or characterized, being the soil one of the most diverse and least studied ecosystems on the planet. To understand and take advantage of favorable effects of soil microorganisms, they must be described and characterizes first. This study was conducted to determine whether soil microbial communities differed in their diversity indexes and structure between organically and conventionally managed cocoa and coffee crops. Six pairs of soil samples collected from the top 10 cm of these crops root zone were analyzed. DNA was extracted from these samples and fragments of 16S bacterial ribosomal DNA and fungal ITS region DNA were amplified by PCR using universal primers. Afterwards, the PCR products were electrophoresed using DGGE. From the DGGE profiles diversity indexes were calculated and the structures of the communities in all the samples compared using hierarchical cluster analysis. No significant differences in diversity indexes, or explicative clusters were detected between the two management systems evaluated.