Arbuscular mycorrhizal fungal communities and soil aggregation as affected by cultivation of various crops during the sugarcane fallow period

Management systems involving crop rotation, ground cover species and reduced soil tillage can improve the soil physical and biological properties and reduce degradation. The primary purpose of this study was to assess the effect of various crops grown during the sugarcane fallow period on the production of glomalin and arbuscular mycorrhizal fungi in two Latosols, as well as their influence on soil aggregation. The experiment was conducted on an eutroferric Red Latosol with high-clay texture (680 g clay kg-1) and an acric Red Latosol with clayey texture (440 g kg-1 clay) in Jaboticabal (São Paulo State, Brazil). A randomized block design involving five blocks and four crops [soybean (S), soybean/fallow/soybean (SFS), soybean/millet/soybean (SMS) and soybean/sunn hemp/soybean (SHS)] was used to this end. Soil samples for analysis were collected in June 2011. No significant differences in total glomalin production were detected between the soils after the different crops. However, total external mycelium length was greater in the soils under SMS and SHS. Also, there were differences in easily extractable glomalin, total glomalin and aggregate stability, which were all greater in the eutroferric Red Latosol than in the acric Red Latosol. None of the cover crops planted in the fallow period of sugarcane improved aggregate stability in either Latosol.

Temporal and Spatial Scaling of the Genetic Structure of a Vector-Borne Plant Pathogen

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Highlights in pathogenic fungal biofilms

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Population Structure and Pathotype Diversity of the Wheat Blast Pathogen Magnaporthe oryzae 25 Years After Its Emergence in Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Pathogen levels and clinical response to periodontal treatment in patients with Interleukin 8 haplotypes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Two Polyketides from a Co-culture of Two Marine-derived Fungal Strains

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Selective photoinactivation of Candida albicans in the non-vertebrate host infection model Galleria mellonella

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comparação de suínos convencionais e SPF (specific pathogen free)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of UV-B radiation on Lecanicillium spp., biological control agents of the coffee leaf rust pathogen

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Understanding the Function of Conserved Variations in the Catalytic Loops of Fungal Glycoside Hydrolase Family 12

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Production of fungal lipases using wheat bran and soybean bran and incorporation of sugarcane bagasse as a co-substrate in solid-state fermentation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Rhizospheric streptomycetes as potential biocontrol agents of Fusarium and Armillaria pine rot and as PGPR for Pinus taeda

Pinus taeda is one of the main timber trees in Brazil, occupying 1.8 million ha with an annual productivity of 25-30 m(3) ha(-1). Another important species is Araucaria angustifolia, belonging to the fragile Rainforest biome, which for decades has been a major source of timber in Brazil. Some diseases that affect the roots and/or the stem of these trees and cause "damping-off" of the seedlings, with economic and environmental losses for the forest sector, are caused by the plant pathogenic fungi Fusarium sp. or Armillaria sp. This research project intended to isolate actinobacteria from the Araucaria rhizosphere, which present an antagonistic effect against these fungi. After the selection of the best pathogen inhibitors, morphologic characteristics, enzyme production, and their effect on the growth of Pinus taeda were studied. The actinobacteria were tested for their antagonistic capacity against Fusarium sp. in Petri plates with PDA as substrate. The inhibition zone was measured after 3, 5, 7, and 10 days. Of all the isolates tested, only two of them maintained inhibition zones up to 4 mm for 10 days. The inhibition of Armillaria sp. was tested in liquid medium and also in Petri dishes through the evaluation of the number of the fungal rhizomorphs in dual culture with the actinobacteria. It was found that all five isolates were able to inhibit the rhizomorph production, with the best performance of the isolate A43, which was capable of inhibiting both fungi, Fusarium and Armillaria. In a greenhouse experiment, the effect of five isolates on the growth of Pinus taeda seedlings was tested. Plant height, stem diameter, root and shoot dry matter were determined. The Streptomyces isolate A43 doubled plant growth. These results may lead to the development of new technologies in the identification of still unknown bacterial metabolites and new management techniques to control forest plant diseases.

Partitioning the net effect of host diversity on an emerging amphibian pathogen

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Accumulation of a complex of pigments in sorghum mesocotyls in response to wounding

Sorghum mesocotyls upon mechanical injury with an abrasive (carborundum) or inoculation with the fungi Helminthosporium carbonum (non-pathogen) or Colletotrichum graminicola (pathogen) accumulate a methanol-soluble pigment complex with an absorption maximum around 480-490 nm. Spectral and thin-layer chromatographic analyses showed that the complexes which accumulated either in response to wounding or inoculation are similar. Thus, it is suggested that the accumulation of the pigmented phytoalexins in sorghum mesocotyls is a non-specific response of the tissues towards mechanical injury or fungal infection.

Narrow Fungal Mycorrhizal Diversity in a Population of the Orchid Coppensia doniana

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)