Arbuscular mycorrhizal fungi associated with the rhizosphere of an endemic terrestrial bromeliad and a grass in the Brazilian neotropical dry forest.

Arbuscular mycorrhizal fungi form symbiotic associations with 80-90% of all known plants, allowing the fungi to acquire plant-synthesized carbon, and confer an increased capacity for nutrient uptake by plants, improving tolerance to abiotic and biotic stresses. We aimed at characterizing the mycorrhizal community in the rhizosphere of Neoglaziovia variegata (so-called `caroa`) and Tripogonella spicata (so-called resurrection plant), using high-throughput sequencing of the partial 18S rRNA gene. Both plants are currently undergoing a bioprospecting program to find microbes with the potential of helping plants tolerate water stress.

Impact of Water Shortage on Soil and Plant Attributes in the Presence of Arbuscular Mycorrhizal Fungi from a Harsh Environment.

Arbuscular mycorrhizal fungi (AMF) play a crucial role in plant health due to their ability to improve tolerance to biotic and abiotic stresses. Our aim was to evaluate the effectiveness of a pool of native AMF from a harsh environment on plant performance and changes in soil attributes under different levels of drought. An experiment using maize was established, varying the soil water content to simulate severe drought (30% of the water-holding capacity [WHC]), moderate (50% of the WHC) and no drought (80% of the WHC, control treatment).

Are the Brazilian prevention values for copper and zinc in soils suitable for protecting earthworms against metal toxicity?

The current Brazilian copper (Cu) and zinc (Zn) prevention values (PV) for soil quality do not take into account the ecotoxicological impacts on soil organisms, which suggests these guiding values may not be protective of soil ecological trophic levels. This study assessed the acute (mortality) and chronic toxicity (reproduction), as well as the cumulative (bioaccumulation) potential of Cu and Zn (pseudo-total and available fractions) for earthworms Eisenia andrei in a Tropical Artificial Soil (TAS) and two tropical field soils (Oxisol and Alfisol). Toxicity data based on pseudo-total fractions were compared to PV.

The use of sewage sludge as remediation for imidacloprid toxicity in soils.

This study investigated the influence of the sewage sludge (SS) soil amendment on the chronic toxicity of imidacloprid (through the seed dressing formulation MUCH 600 FS®-600 g active ingredient L) to collembolans Folsomia candida. Individuals 10-12 days old were exposed to two contrasting tropical soils (Oxisol and Entisol) amended with SS doses (0, 20, 40, 80, 160, and 320 g SS kg soil; the SS doses have low intrinsic toxicity, which was checked before its application) in a full factorial combination with five imidacloprid concentrations (varying from 0.25 to 4 mg kg in Oxisol and 0.

Arbuscular mycorrhizal fungi community in soils under desertification and restoration in the Brazilian semiarid.

Soil desertification has a significant social, economic, and environmental impact worldwide. Mycorrhizal diversity remains poorly understood in semiarid regions impacted by desertification, especially in Brazilian drylands. More importantly, positive impacts of grazing exclusion on mycorrhizal communities are still incipient.

Arbuscular Mycorrhizal Fungi and Soil Quality Indicators in genotypes With Different Drought Tolerance Levels.

Silviculture has great importance worldwide, and the use of species, which account for 75% of the local planted forest in Brazil, is one of the factors that contributes to the success of this activity in the country. Despite its adaptability, the yield of is often affected by climate change, particularly water deficiency. Plants have developed strategies to mitigate water stress, for example, through their association with mycorrhizal fungi.

Does Organomineral Fertilizer Combined with Phosphate-Solubilizing Bacteria in Sugarcane Modulate Soil Microbial Community and Functions?

Soil bacterial and fungal communities are suitable soil ecosystem health indicators due to their sensitivity to management practices and their role in soil ecosystem processes. Here, information on composition and functions of bacterial and fungal communities were evaluated at two phenological stages of sugarcane (six and twelve months, equivalent to the most intensive vegetative stage and to final maturation, respectively) when organomineral fertilizer, combined with phosphate-solubilizing bacteria (PSB), was added into the soil. Organic compost enriched with apatite (C + A) or phosphorite (C + P) and compost without phosphate enrichment (C) were used in the presence or absence of PSB.

Toxicity of imidacloprid to collembolans in two tropical soils under different soil moisture.

Shifts in precipitation regimes due to the predicted climate changes can alter the water content in tropical soils and, consequently, may influence the toxicity of pesticides to soil fauna. This study assessed the influence of soil moisture content on the toxicity of the insecticide imidacloprid to the collembolans Folsomia candida in two tropical soils and evaluated the risk of this active ingredient for this species in the soils tested through the toxicity exposure ratio approach. Acute and chronic toxicity tests with F.

How deep can ectomycorrhizas go? A case study on Pisolithus down to 4 meters in a Brazilian eucalypt plantation.

Despite the strong ecological importance of ectomycorrhizal (ECM) fungi, their vertical distribution remains poorly understood. To our knowledge, ECM structures associated with trees have never been reported in depths below 2 meters. In this study, fine roots and ECM root tips were sampled down to 4-m depth during the digging of two independent pits differing by their water availability.

Ecotoxicological assessment of Fluazuron: effects on Folsomia candida and Eisenia andrei.

The cattle production in Brazil has increased considerably in the last years, mainly due to the control of parasite infestation of the animals, which cause loss of productivity to the sector. Fluazuron is an active ingredient (a.i.

Shifts in the bacterial community composition along deep soil profiles in monospecific and mixed stands of Eucalyptus grandis and Acacia mangium.

Our knowledge of the rhizosphere bacterial communities in deep soils and the role of Eucalyptus and Acacia on the structure of these communities remains very limited. In this study, we targeted the bacterial community along a depth profile (0 to 800 cm) and compared community structure in monospecific or mixed plantations of Acacia mangium and Eucalyptus grandis. We applied quantitative PCR (qPCR) and sequence the V6 region of the 16S rRNA gene to characterize composition of bacterial communities.

Ecotoxicological impact of arsenic on earthworms and collembolans as affected by attributes of a highly weathered tropical soil.

High levels of heavy metals in soils may impose serious impacts on terrestrial organisms. In Brazil, the prevention values for evaluating the ecological risk of these elements are based only on soil chemical analyses and/or on data from ecotoxicological assays performed in soils of temperate regions. However, the attributes of the Brazilian highly-weathered tropical soils can influence the availability of heavy metals for soil fauna, resulting in different toxic values.

Diversity of Arbuscular Mycorrhizal Fungi in a Brazilian Atlantic Forest Toposequence.

The diversity of arbuscular mycorrhizal fungi (AMF) was studied in the Atlantic Forest in Serra do Mar Park (SE Brazil), based on seven host plants in relationship to their soil environment, altitude and seasonality. The studied plots along an elevation gradient are located at 80, 600, and 1,000 m. Soil samples (0-20 cm) were collected in four seasons from SE Brazilian winter 2012 to autumn 2013.

Ecotoxicological evaluation of swine manure disposal on tropical soils in Brazil.

Swine production in Brazil results in a great volume of manure that normally is disposed of as agricultural fertilizer. However, this form of soil disposal, generally on small farms, causes the accumulation of large amounts of manure and this results in contaminated soil and water tables. To evaluate the effects of increasing concentrations of swine manure on earthworms, several ecotoxicological tests were performed using Eisenia andrei as test organism in different tropical soils, classified respectively as Ultisol, Oxisol, and Entisol, as well as Tropical Artificial Soil (TAS).

Soil properties discriminating Araucaria forests with different disturbance levels.

Soil biological, chemical, and physical properties can be important for monitoring soil quality under one of the most spectacular vegetation formation on Atlantic Forest Biome, the Araucaria Forest. Our aim was to identify a set of soil variables capable of discriminating between disturbed, reforested, and native Araucaria forest soils such that these variables could be used to monitor forest recovery and maintenance. Soil samples were collected at dry and rainy season under the three forest types in two state parks at São Paulo State, Brazil.

Indole-3-acetic acid producing root-associated bacteria on growth of Brazil Pine (Araucaria angustifolia) and Slash Pine (Pinus elliottii).

Araucaria forests in Brazil today correspond to only 0.7 % of the original 200 km(2) of natural forest that covered a great part of the southern and southeastern area of the Atlantic Forest and, although Araucaria angustifolia is an endangered species, illegal exploitation is still going on. As an alternative to the use of hardwoods, Pinus elliottii presents rapid growth and high tolerance to climatic stress and low soil fertility or degraded areas.

Plant growth promoting bacteria in Brachiaria brizantha.

Brachiaria brizantha is considered one of the preferred fodders among farmers for having high forage yield and large production of root mass. The association of beneficial bacteria with these grasses can be very valuable in the recovery of the pasture areas with nutritional deficiency. With the aim of studying this possibility, we carried out the sampling of soil and roots of B.

Isolation, selection and characterization of root-associated growth promoting bacteria in Brazil Pine (Araucaria angustifolia).

Araucaria angustifolia, a unique species of this genus that occurs naturally in Brazil, has a high socio-economic and environmental value and is critically endangered of extinction, since it has been submitted to intense predatory exploitation during the last century. Root-associated bacteria from A. angustifolia were isolated, selected and characterized for their biotechnological potential of growth promotion and biocontrol of plant pathogenic fungi.