Biochar made-up of dry olive residue (DOR), a biomass resulting from the olive oil extraction industry, has been proposed to be used as a reclamation agent for the recovery of metal contaminated soils. The aim of the present study was to investigate whether the soil application of DOR-based biochar alone or in combination with arbuscular mycorrhizal fungi (AMF) leads to an enhancement in the functionality and abundance of microbial communities inhabiting metal contaminated soils. To study that, a greenhouse microcosm experiment was carried out, where the effect of the factors (i) soil application of DOR-based biochar, (ii) biochar pyrolysis temperature (considering the variants 350 and 500 °C), (iii) soil application dose of biochar (2 and 5%), (iv) soil contamination level (slightly, moderately and highly polluted), (v) soil treatment time (30, 60 and 90 days) and (vi) soil inoculation with Funneliformis mosseae (AM fungus) on β-glucosidase and dehydrogenase activities, FA (fatty acid)-based abundance of soil microbial communities, soil glomalin content and AMF root colonization rates of the wheat plants growing in each microcosm were evaluated. Biochar soil amendment did not stimulate enzyme activities but increased microbial abundances. Dehydrogenase activity and microbial abundances were found to be higher in less contaminated soils and at shorter treatment times. Biochar pyrolysis temperature and application dose differently affected enzyme activities, but while the first factor did not have a significant effect on glucosidase and dehydrogenase, a higher biochar dose resulted in boosted microbial abundances. Soil inoculation with F. mosseae favored the proliferation of soil AMF community and increased soil glomalin content as well as rates of AMF root colonization. This factor also interacted with many of the others evaluated to significantly affect soil enzyme activities, microbial abundances and AMF community. Our results indicate that the application of DOR-based biochar along with AMF fungi is an appropriate approach to improve the status of microbial communities in soils with a moderate metal contamination at short-term.

• MeSH
• dřevěné a živočišné uhlí MeSH
• houby MeSH
• kořeny rostlin chemie   MeSH
• kovy farmakologie   MeSH
• látky znečišťující půdu * analýza   MeSH
• mykorhiza * chemie   MeSH
• Olea * MeSH
• oxidoreduktasy MeSH
• půda chemie   MeSH
• půdní mikrobiologie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• biochar MeSH Prohlížeč
• dřevěné a živočišné uhlí MeSH
• kovy MeSH
• látky znečišťující půdu * MeSH
• oxidoreduktasy MeSH
• půda MeSH

Root colonization by arbuscular mycorrhizal fungi (AMF) can be quantified by different approaches. We compared two approaches that enable discrimination of specific AMF taxa and are therefore emerging as alternative to most commonly performed microscopic quantification of AMF in roots: quantitative real-time PCR (qPCR) using markers in nuclear ribosomal DNA (nrDNA) and mitochondrial ribosomal DNA (mtDNA). In a greenhouse experiment, Medicago truncatula was inoculated with four isolates belonging to different AMF species (Rhizophagus irregularis, Claroideoglomus claroideum, Gigaspora margarita and Funneliformis mosseae). The AMF were quantified in the root samples by qPCR targeted to both markers, microscopy and contents of AMF-specific phospholipid fatty acids (PLFA). Copy numbers of nrDNA and mtDNA were closely related within all isolates; however, the slopes and intercepts of the linear relationships significantly differed among the isolates. Across all isolates, a large proportion of variance in nrDNA copy numbers was explained by root colonization intensity or contents of AMF-specific PLFA, while variance in mtDNA copy numbers was mainly explained by differences among AMF isolates. We propose that the encountered inter-isolate differences in the ratios of mtDNA and nrDNA copy numbers reflect different physiological states of the isolates. Our results suggest that nrDNA is a more suitable marker region than mtDNA for the quantification of multiple AMF taxa as its copy numbers are better related to fungal biomass across taxa than are copy numbers of mtDNA.

• Klíčová slova
• Arbuscular mycorrhizal fungi, Isolate discrimination, Microsymbiont screening, Mitochondrial DNA, Molecular genetic quantification, Nuclear ribosomal DNA, PLFA, Real-time PCR,
• MeSH
• buněčné jádro genetika   MeSH
• DNA fungální genetika   MeSH
• Glomeromycota genetika   MeSH
• kořeny rostlin mikrobiologie   MeSH
• kvantitativní polymerázová řetězová reakce * MeSH
• Medicago truncatula mikrobiologie   MeSH
• mitochondriální DNA genetika   MeSH
• mykorhiza genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DNA fungální MeSH
• mitochondriální DNA MeSH