Soil Properties shape species diversity and community composition of native arbuscular mycorrhizal fungi in Retama raetam roots growing on arid ecosystems of Tunisia

The aim of this study was to identify the major environmental factors affecting the Arbuscular Mycorrhizal Fungi (AMF) diversity and community composition in the roots of Retama raetam growing on arid ecosystems of Tunisia AM Fungi were assessed by cloning and sequencing of the AMF SSU rRNA gene and therefore checked against NCBI GenBank and MaarjAA4 database. Thirteen operational taxonomic units (OTUs) were identified in R. raetam roots and AMF community was dominated by Glomeraceae. Of the totality of OTUs, ten matched previously known virtual taxa (VTX) and 3 OTUs were treated as novel VT and grouped into 3 putative new AMF taxa (pNTX). Correlation analysis reported that high available phosphorus content and high electrical conductivity in the soil decrease AMF richness and diversity. Interestingly, Principal Component Analysis (PCA) and Monte Carlo permutation tests on Canonical Correspondence Analysis (CCA) indicated that soil physic-chemical properties such as soil total nitrogen (TN), soil-available P, EC, and soil texture affected the AMF community composition. No significant relation was found between AMF distribution and soil organic carbon (OC) and soil pH. Our findings provide insights into the nature of AMF communities colonizing R. raetam roots and help to link fungal distribution to specific soil properties, which could be exploited in the identification of a wider variety of fungal strains as potential inoculants for rehabilitation and restoration program

A PCR-based diagnostic assay for detecting DNA of the olive fruit fly, Bactrocera oleae, in the gut of soil-living arthropods

Bactrocera oleae (Rossi) (Diptera: Tephritidae) is considered the most devastating pest of the olive tree worldwide. In an effort to develop management and biological control strategies against this pest, new molecular tools are urgently needed. In this study, we present the design of B. oleae-specific primers based on mitochondrial DNA sequences of cytochrome oxidase subunit I (COI) gene. Two pairs of B. oleae-specific primers were successfully designed and named as SBo1-F/SBo1-R and SBo2-F/SBo1-R, being able to amplify 108 and 214 bp COI fragments, respectively. The specificity of designed primers was tested by amplifying DNA from phylogenetically related (i.e. Diptera order) and other non-pest insects living in olive groves from the Mediterranean region. When using these primers on a PCR-based diagnostic assay, B. oleae DNA was detected in the gut content of a soil-living insect, Pterostichus globosus (Fabricius) (Coleoptera: Carabidae). The detection of B. oleae DNA in the guts of arthropods was further optimized by adding bovine serum albumin enhancer to the PCR reaction, in order to get a fast, reproducible and sensitive tool for detecting B. oleae remains in the guts of soil-living arthropods. This molecular tool could be useful for understanding pest-predator relationships and establishing future biological control strategies for this pest.This work was supported by FEDER Funds throughout Programa Operacional Factores de Competitividade – COMPETE and National Funds throughout FCT – Fundação para a Ciência e Tecnologia, within the project EXCL/ AGR-PRO/0591/2012: Olive crop protection in sustainable production under global climatic changes: linking ecological infrastructures to ecosystem functions. M. Rejili was supported by a fellowship on the frame of Erasmus Mundus EU MARE NOSTRUM.info:eu-repo/semantics/publishedVersio