MICROBIAL DIVERSITY IN SOIL: Selection of Microbial Populations by Plant and Soil Type and Implications for Disease Suppressiveness

Abstract

An increasing interest has emerged with respect to the importance of microbial diversity in soil habitats. The extent of the diversity of microorganisms in soil is seen to be critical to the maintenance of soil health and quality, as a wide range of microorganisms is involved in important soil functions. This review focuses on recent data relating how plant type, soil type, and soil management regime affect the microbial diversity of soil and the implication for the soil's disease suppressiveness. The two main drivers of soil microbial community structure, i.e., plant type and soil type, are thought to exert their function in a complex manner. We propose that the fact that in some situations the soil and in others the plant type is the key factor determining soil microbial diversity is related to the complexity of the microbial interactions in soil, including interactions between microorganisms and soil and microorganisms and plants. A conceptual framework, based on the relative strengths of the shaping forces exerted by plant and soil versus the ecological behavior of microorganisms, is proposed.

Dynamics of the bacterial community structure in the rhizosphere of a maize cultivar

“…Another study conducted in the carbonate-rich soil (pH 8.5) using 16S rRNA clone library analysis showed that Pseudomonas and Lysobacter genera constituted 45% of the total bacterial abundance in the maize rhizosphere (García-Salamanca et al, 2013). Though exact mechanisms for such differences are not completely understood, because these studies were all conducted on different soil types, it is likely that soil type may be one of the most important environmental variables influencing the structure of the maize root-inhabiting bacterial community at low taxonomic levels (Berg and Smalla, 2009;Castellanos et al, 2009;Garbeva et al, 2004). Growth-stage related dynamics and the differences in rhizosphere bacterial community structure from different soil types further support the general concept that plant and soil type cooperatively shape the structure of microbial community in the rhizosphere (Berg and Smalla, 2009).…”

Effect of sorghum seedlings, and previous crop, on soil fluorescent Pseudomonas spp.

“…Additionally, relative totals may not demonstrate huge changes but may reflect changes in specific groups of organisms (Curl and Truelove 1986). It is not known whether subtle but statistically significant shifts in one or more factors would have at least minor impact on crops in the field (Degens et al 2001;Garbeva et al 2004). Nonetheless, small differences (less than 10-fold) should be biologically interpreted with caution.…”

Diversidade de fungos micorrízicos arbusculares em pomar orgânico no semiárido cearense

“…A diversidade de microrganismos é fundamental para a manutenção da saúde e da qualidade do solo, estando envolvida em importantes funções desse ecossistema (GARBEVA et al, 2004). Entre os organismos funcionais do solo e associados ao sistema radicular, destacam-se os fungos micorrízicos arbusculares (FMA), pertencentes ao filo Glomeromycota, com 230 espécies descritas (OEHL et al, 2011).…”