Community analysis of arbuscular mycorrhizal fungi associated with Ammophila arenaria in Dutch coastal sand dunes

Abstract

A polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) approach for the detection and characterization of arbuscular mycorrhizal fungi (AMF) 18S ribosomal DNA (rDNA) was developed and applied to the study of AMF communities associated with the main sand-stabilizing plant species of the Dutch sand dunes, marram grass (Ammophila arenaria, L.). DNA was extracted directly from plant roots, soil or isolated AMF spores, and prominent bands resulting from AMF-specific DGGE profiles were excised for sequence analysis. This strategy provided a robust means of detecting and identifying AMF-like species without the use of trap plant cultivation methods. A number of Glomus-like and Scutellospora-like sequences was detected, including a putatively novel Glomus species, and differences were observed in the dominant AMF-like populations detected in healthy vs. degenerating stands of A. arenaria and in bulk sand dune soil. It has previously been suggested that plant pathogens, such as fungi and nematodes, may contribute to the decline of A. arenaria. Although no causal relationship can be drawn between the observed differences in the dominantly detected AMF-like populations and the vitality of plant growth, these results indicate that mutualistic interactions between this plant and AMF should not be overlooked when examining the role of soil-borne microorganisms in vegetation dynamics. In addition, there were discrepancies observed between the AMF-like groups detected in spore populations vs. direct 18S rDNA analysis of root material, corroborating previous suggestions that spore inspection alone may poorly represent actual AMF population structure.

Occurrence and diversity of arbuscular mycorrhizal fungi in trap cultures from soils under different land use systems in the Amazon, Brazil

“…Detection of this variability is important to understand the biology of these fungi in terrestrial systems and address questions whether changes in the ecosystem components (in this study represented by LUS) impacts the fitness (measured by sporulation) of the indigenous AMF. Moreover, detecting isolates with different sporulation rates represents a first step for screening the genetic diversity exhibited by AMF species/strains over distinct geographic locations which may impact plant benefits these fungi confer to their hosts (35) and allows further detection of genetic variation using molecular tools (12).…”

“…Diversity of AMF species is measured mainly by extracting, counting and identifying their field collected asexual spores, the fungal propagule that possess morphological characters to define species in this group of organisms (21) although molecular techniques have been revealed an useful tool for characterization and identification of AMF (12). Species richness and abundance of AMF in a given ecosystem are influenced by large scale historical factors like long-distance dispersion and vicariance (25) and local ecological factors such as plant cover and host diversity, soil cultivation and disturbance and seasonality (32), being all of these factors important in the study of AMF diversity (21).…”

High richness of ectomycorrhizal fungi and low host specificity in a coastal sand dune ecosystem revealed by network analysis

“…2002; Błaszkowski and Czerniawska 2011; etc.). To our knowledge, EM communities and multispecies network have not previously been described in coastal dune ecosystems.…”

Denaturing gradient gel electrophoresis as a fingerprinting method for the analysis of soil microbial communities

“…In order to specifically analyze the fungi belonging to Basidiomycota, the reverse primer ITS4B 5'-CAG GAG ACT TGT ACA CGG TCC AG-3' was used instead of ITS4 in the first round of the nested PCR. Kowalchuk et al (2002) same for the 18S-and ITS-based primers (Anderson et al 2003). However, it is generally accepted that the ITS region is preferred due to its higher variability.…”