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The Brazilian pepper tree (Schinus terebinthifolius) is an invasive species that requires significant disturbance to eradicate. Previous studies have identified associations between the Brazilian pepper tree and ectomycorrhizal fungi (EMF). However, limited research has explored the connection between disturbance from removal and the effect on EMF. This study investigated the sensitivity of EMF and the broader fungal community to the full and selective removal of the Brazilian pepper tree. During the selective removal of Brazilian pepper tree, we examined the mycorrhizal community of the Arroyo willow (Salix lasiolepis) to assess the influence of the restoration disturbance on native species. We used ITS2 sequencing to identify the EMF present during the restoration. Our expectation was that both removal efforts would reduce the presence of EMF. Contrary to our predictions, full removal increased EMF richness and relative abundance in the soil. As anticipated, selective removal reduced the richness and relative abundance of EMF associated with soil. Selective removal led to a decrease in the richness of EMF in arroyo willow roots with no effect on relative abundance. Moreover, fungal community composition in soil and roots shifted significantly during selective and full removal. However, the community composition of EMF, specifically, remained constant across treatment types. During full removal efforts, the application of organic soil amendments may have contributed to the increase in the diversity and relative abundance of EMF. Selective removal will require additional measures, such as soil amendments, to curtail the loss of EMF. [ABSTRACT FROM AUTHOR]

Sustainable agriculture is based on improving soil microbial activities through new practices including the use of biostimulants such as arbuscular mycorrhizal fungi (AMF). However, many factors, such as plant cultivar, influences the success of mycorrhizal inoculation in field. We investigated the impact of inoculation with Rhizophagus irregularis DAOM 197198 (AGTIV®, Premier Tech) on three potato cultivars (Solanum tuberosum cv. Écrin, Fontane, Manitou ® Desmazières) in two microplots in North of France. In each trial, sampling was carried out (i) at the tuber filling stage to study potato development and nutrition, as well as bacterial and fungal diversity in the roots, and (ii) at maturity to determine tuber yield. Our results showed that inoculation (i) homogenize tuber calibre (ii) significantly increased potato yield and financial income for Manitou plants, (iii) homogenized the phosphate root-to-shoot ratio, and (iv) did not modify neither the taxonomic composition nor the relative abundance of bacteria, fungi and AMF associated with potato roots whatever the potato cultivar. Our results suggest that the positive effects of the inoculation with R. irregularis DAOM 197198 might depend on the potato cultivar, but further investigations are needed to understand the impact of different soils and agricultural systems on inoculation success. [ABSTRACT FROM AUTHOR]

There has been a surge in industries built on the production of arbuscular mycorrhizal (AM) fungal-based inoculants in the past few decades. This is not surprising, given the positive effects of AM fungi on plant growth and nutritional status. However, there is growing concern regarding the quality and efficacy of commercial inoculants. To assess the potential benefits and negative consequences of commercial AM fungal inoculants in grasslands, we conducted a controlled growth chamber study assessing the productivity and AM fungal root colonization of nine grassland plant species grown in grassland soil with or without one of six commercial AM fungal products. Our research showed no evidence of benefit; commercial inoculants never increased native plant biomass, although several inoculants decreased the growth of native species and increased the growth of invasive plant species. In addition, two commercial products contained excessive levels of phosphorus or nitrogen and consistently reduced AM fungal root colonization, indicating an unintentional de-coupling of the symbiosis. As there is little knowledge of the ecological consequences of inoculation with commercial AM fungal products, it is critical for restoration practitioners, scientists, and native plant growers to assess the presence of local AM fungal communities before investing in unnecessary, or possibly detrimental, AM fungal products. [ABSTRACT FROM AUTHOR]

There has been a surge in industries built on the production of arbuscular mycorrhizal (AM) fungal-based inoculants in the past few decades. This is not surprising, given the positive effects of AM fungi on plant growth and nutritional status. However, there is growing concern regarding the quality and efficacy of commercial inoculants. To assess the potential benefits and negative consequences of commercial AM fungal inoculants in grasslands, we conducted a controlled growth chamber study assessing the productivity and AM fungal root colonization of nine grassland plant species grown in grassland soil with or without one of six commercial AM fungal products. Our research showed no evidence of benefit; commercial inoculants never increased native plant biomass, although several inoculants decreased the growth of native species and increased the growth of invasive plant species. In addition, two commercial products contained excessive levels of phosphorus or nitrogen and consistently reduced AM fungal root colonization, indicating an unintentional de-coupling of the symbiosis. As there is little knowledge of the ecological consequences of inoculation with commercial AM fungal products, it is critical for restoration practitioners, scientists, and native plant growers to assess the presence of local AM fungal communities before investing in unnecessary, or possibly detrimental, AM fungal products.

A field trial was conducted in two localities of the Ecuadorian Andes to evaluate potato ( Solanum tuberosum c.v. INIAP - Fripapa) response to inoculation with four commercial products containing the arbuscular mycorrhizal fungus (AMF) strain Rhizophagus irregularis DAOM 197198. In parallel, potato roots were analysed using 454 GS-FLX+ sequencing of c. 800 bp of the nuclear LSU rRNA gene to assess the associated AMF communities. To evaluate inoculation success, sequence reads of R. irregularis on the root samples were compared between inoculated and not inoculated plants by analysing the frequency of occurrence (FO) and relative read abundance (RA). None of the commercial products significantly increased potato yield. Instead, the AMF communities were dominated by an unknown Acaulospora sp. (Sp14) found at high FO and RA in both localities. Rhizophagus irregularis was found in most of the roots of both inoculated and not inoculated plants at both localities. However, its abundance was unexpectedly low indicating poor inoculum establishment. Clearly, many factors have to be taken in consideration for the successful application of AMF-based inoculants. For the Ecuadorian field trials, several causes may explain the lack or poor establishment of R. irregularis such as inoculation technique, agricultural practices, biotic and abiotic conditions and competition with native AMF species. [ABSTRACT FROM AUTHOR]

Aerated lagoons are a main unit operation for wastewater treatment in the paper industry. Many such operations involve inoculation with bacterial formulations in which in situ effectiveness has not been proven; this can be translated into low efficiency in treatment and unnecessary investments. Lack of knowledge of bacterial biodiversity present in a lagoon limits the capacity to exploit the maximum degradation. To overcome such problems, various methods to identify and study these microorganisms have been developed. In this study, a PCR-DGGE analysis was performed to estimate the bacterial diversity and to verify the presence of bacteria present in a commercial inoculum in two aerated lagoons of a pulp and paper effluent. Phylogenetic affiliation of predominant member's correspondent to γ- and β-proteobacteria and Firmicutes were found. The dominant bacteria present in lagoon 2 belonged to the following genus Microbacterium sp. Rhodocyclaceae sp., Eubacterium sp. and B. subtilis. In lagoon 1 the dominant genus included Microbacterium sp., Rhodocyclaceae sp. Tepidimonas sp., Acetanaerobacterium sp., and Flavobacteria sp. The two characterized lagoons were not similar to the commercial inoculum. In addition, nondominant bacteria (less relative intensity) were composed mostly of bacteria of the commercial inoculum. [ABSTRACT FROM AUTHOR]

We tested the hypothesis that field applications of arbuscular mycorrhizal (AM) inocula would increase root colonization and plant performance in a coastal sage scrub (CSS) restoration project in Southern California. We applied commercial or native inocula (from nearby reference shrublands) as we seeded plots with native shrubs, forbs, and grasses. A control treatment was seeded but received no inocula. After 6 months, AM root colonization did not differ significantly among treatments. Likewise, neither inoculum type significantly altered shoot biomass of native shrubs and forbs at 6 months, or density of adult and seedling shrubs at 10 months. Notably, shoot height at 10 months was shorter in plots treated with commercial inoculum compared with the controls. In addition, flower and flower bud production by Salvia columbariae did not significantly respond to either inoculum type. Altogether, we found no evidence that AM inoculation improved restoration success in our CSS system. [ABSTRACT FROM AUTHOR]

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