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São Paulo, Brazil

Bernardes F.S.,University of Sao Paulo | Patricio F.R.A.,Instituto Agronomico IAC | Santos A.S.,Instituto Biologico IB | dos Freitas S.S.,Embrapa Tabuleiros Costeiros
Summa Phytopathologica | Year: 2010

Rhizobacteria of the fluorescent group of Pseudomonas spp. Were selected for both their capacity in the growth promotion of lettuce seedlings (Lactuca sativa L.) and antagonistic activity against Pythium aphanidermatum from test in vitro. Then, in hydroponic system was assayed the previous application of the Pseudomonas strains in order to reduce damages caused by P. aphanidermatum in cucumber (Cucumis sativus) for induced systemic resistance (ISR), using a technical splitroot. The variables shoots and roots dry weight and root length were used in evaluation. The production of antagonistic and/or growth promoters compounds by rhizobacteria strains was observed to associate its activity with the results obtained in the tests under hydroponic system and in vitro conditions. In the in vitro experiment, strains Ps 140B and Ps 140C provided the largest development of plants (root and hypocotyls) in the treatments with and without pathogen. Some strains tested indicating a possible expression of ISR in in vivo experiments. No correspondence among the compounds produced by rhizobacteria, plant growth promotion and bioprotection was detected. Source

Duarte L.M.L.,Instituto Biologico IB | Alexandre M.A.V.,Instituto Biologico IB | Gobatto D.,Instituto Biologico IB | Kitajima E.W.,University of Sao Paulo | Harakava R.,Laboratory Of Bioquimica
Plant Disease | Year: 2014

In November 2012, plants of Russell prairie gentian (Eustoma grandiflorum, Lisianthus russellianus) were collected from a commercial greenhouse in Atibaia, SP, Brazil, displaying necrotic spots on leaves and necrosis on stems, followed by generalized systemic necrosis. Disease symptom incidence was estimated at 10%. Preliminary electron microscopy observations of negatively stained leaf extracts prepared from those lesions revealed the presence of a large number of spherical tospovirus-like, approximately 100 nm in diameter. Samples of infected leaves were ground in 0.01 M phosphate buffer containing 0.5% sodium sulphide and mechanically inoculated in six plants of each species of Nicotiana glutinosa, N. tabacum cv. White Burley, N. megalosiphon, N. debneyii, Datura stramonium, Chenopodium amaranticolor, C. quinoa, and E. grandiflorum. All inoculated plants displayed local lesions 4 to 5 days after inoculation, while N. debneyii and D. stramonium showed systemic symptoms, typical of Tospovirus infection. In addition, E. grandiflorum reproduced the original symptoms. Total RNA was extracted from infected E. grandiflorum and D. stramonium, and reverse transcription (RT)-PCR was performed using universal primers BR60 and BR65 (2) targeting conserved regions of the nucleocapsid gene (N). The amplification products of approximately 450 bp were purified, cloned, and sequenced. The unknown virus was identified as Chrysanthemum stem necrosis virus (CSNV-Lis) based on host range and nucleotide sequence (Genbank Accession No. KC894721) and showed 99% identity with a CSNV chrysanthemum isolate from Japan (AB600872). Maximum likelihood phylogenetic analysis using nine homologous CSNV sequences available in GenBank classified CSNV-Lis into a monophyletic group formed by chrysanthemum isolates from Japan and China while a Japanese lisianthus isolate was separately clustered. CSNV is a member of the genus Tospovirus (Bunyaviridae) and was first reported on chrysanthemum in Brazil (1) and later in the Netherlands, Slovenia, United Kingdom, and Japan (3). Despite scattered recent reports of CSNV, the simultaneous production of chrysanthemum and lisianthus crops along the year by Brazilian farmers has contributed to the virus maintenance in the field. The high identity between Brazilian and Japanese isolates of CSNV suggest a possible reintroduction of the virus through exchange of vegetative propagating material. Source

De Souza A.D.,Instituto Biologico IB | De Souza A.D.,Laboratorio Of Fitossanidade | Aoyama E.M.,Centro Universitario Norte do Espirito Santo | Aoyama E.M.,Federal University of Espirito Santo | Furlan M.R.,Sao Paulo State University
Revista em Agronegocio e Meio Ambiente | Year: 2015

Passiflora ligularis Juss. is highly consumed by people, especially in natura, as juice and ice-cream. However, no successful research is extant on its development and adaptation in Brazil. The high costs of granadilla and the difficulty to buy it, even in supermarkets, justify analysis to verify the adaptability of the species, with production potential, at least in some regions of the country. Current assay is a contribution for research on the behavior of granadilla in Brazil so that information on the effect of time and storage conditions may be obtained for seed germination and the early development stages of the seedlings. Granadilla seeds came from Colombian fruit and the assay focused on the evaluation of seed quality with three different storage periods, with emergence velocity index (EVI) and percentage of seedlings' germination and development. Treatments comprised Treatment A - seeds stored for 24 months; Treatment B - seeds stored for 3 months; Treatment C - seeds without storage. Randomized design with four replications of 50 seeds was employed and comparisons made by Tukey's test at 1% probability. Seedlings should be obtained from seeds kept in cold chambers for a period of more than 101 days. Seeds which had been only recently removed from the fruit have low germination percentage and small height growth when compared with plants from seeds stored for 24 months. © 2015, University Center of Maringa. All rights reserved. Source

Torres L.C.,Catholic University Dom Bosco | Lourencao A.L.,Instituto Agronomico IAC | Costa V.A.,Instituto Biologico IB | Souza B.,Federal University of Lavras | And 2 more authors.
Neotropical Entomology | Year: 2014

Collections of natural enemies of Bemisia tabaci biotype B (Genn.) (Hemiptera: Aleyrodidae) were made in Lavras, state of Minas Gerais, Brazil. In the greenhouse, 6,495 predators and 16,628 parasitoids belonging to three families were collected. In the field, 267 predators and 344 parasitoids belonging to five families were found. For the first time in Brazil, five species of predators associated with this whitefly were reported. Because of the diversity of natural enemies of B. tabaci biotype B recorded, this study points out the importance of these data for studies on integrated pest management. © 2013 Sociedade Entomológica do Brasil. Source

Batista I.C.,Instituto Biologico IB | Eiras M.,Instituto Biologico IB | Harakava R.,Instituto Biologico IB | Colariccio A.,Instituto Biologico IB
Bragantia | Year: 2012

A Tymovirus isolated from seeds of tomato (Solanum lycopersicum) cv. 'Paronset' with necrosis, named TyToRS08 isolate, was characterized by its host range, physical-chemical, serological and molecular properties. Firstly, it was successfully transmitted by mechanical inoculation by infected seeds, and the host range was restricted to species of Amaranthaceae, Chenopodiaceae and Solanaceae. The symptoms induced by the virus in tomatoes 'Alambra', 'Thomas', 'Diva', 'Romana' and 'Graziela' were mainly mosaic and white necrosis. Nicotiana sylvestris, N. tabacum 'Samsun', 'White Burley' and 'Xanthi' were symptomless. The virus was detected in seeds from five tomato cultivars, but it was not detected in seedlings from these infected seeds. The purified preparation had a high concentration of 1.04 mg mL-1, and the title of the polyclonal antiserum produced, evaluated in PTA-ELISA, was 1/32.768. RT-PCR was performed with degenerated primers directed to the ORF 1 of the tymoviruses, resulting in a DNA fragment of 700 bp. The sequence analysis revealed that TyToRS08 isolate presents higher values of percentage of identity with other species of Tymovirus. The highest identity values were under 70%, indicating that TyToRS08 should be a distinct species of the genus Tymovirus, with great epidemiological importance due to its high stability and potential to be spread by tomato seeds. Source

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