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São Paulo, Brazil

Cabral C.S.,University of Pernambuco | Brunelli K.R.,Sakata Seed Sudamerica Ltda | Costa H.,Incaper Venda Nova do Imigrante | Fonseca M.E.N.,Embrapa Hortalicas | And 2 more authors.
Tropical Plant Pathology | Year: 2014

The objective of this work was to assess the virulence to lettuce cultivars and host specificity and to identify races of Fusarium oxysporum f. sp. lactucae (FOLac) isolates associated with lettuce wilt in Brazil. Thirty-one isolates identified based on morphology were inoculated in a set of lettuce cultivars for race determination. Plantlets of 'Elisa', 'Vera', and 'Red Salad Bowl' cultivars were inoculated with all isolates using a root-dipping method. Isolates were also inoculated in species of Asteraceae and other botanical families. 'Elisa' and 'Vera' were susceptible to 27 isolates while 'Red Salad Bowl' was resistant to all isolates. Plants other than lettuce were not infected by any of the isolates, suggesting their specificity to lettuce. All pathogenic isolates were assigned to race 1 and used to evaluate a PCR protocol with primers targeting race 1. Only amplicons associated with race 1 pattern were observed for all pathogenic isolates but not for one non-pathogenic isolate, thus leading us to conclude that FOLac race 1 is so far the sole causal agent of lettuce wilt in Brazil. © by the Brazilian Phytopathological Society.

Barbosa J.C.,University of Sao Paulo | Costa H.,Instituto Capixaba Of Pesquisa | Gioria R.,Sakata Seed Sudamerica Ltda | Rezende J.A.M.,University of Sao Paulo
Tropical Plant Pathology | Year: 2011

Tomato chlorosis virus (ToCV) is a species in the genus Crinivirus, transmitted by Bemisia tabaci biotype B, first detected in Brazil in 2006 in the county of Sumaré, State of São Paulo. During the period from 2007 to 2010, RT-PCR analyses followed by nested-PCR with specific primers for ToCV detection, and sequencing of the amplicons, confirmed the presence of this virus in samples of symptomatic tomato plants (Solanum lycopersicum) from crops in counties in the states of Bahia (BA), Espírito Santo (ES), Goiás (GO), Minas Gerais (MG), and Rio de Janeiro (RJ). This is the first ToCV report for the states of BA, ES, GO, MG, and RJ, suggesting that this virus is widely disseminated in Brazil. Copyright by the Brazilian Phytopathological Society. Printed in Brazil.

Areas M.S.,Sao Paulo State University | Goncalves R.M.,Sao Paulo State University | Soman J.M.,Sao Paulo State University | Sakate R.K.,Sao Paulo State University | And 3 more authors.
Journal of Phytopathology | Year: 2015

Bacterial spot, caused by Xanthomonas spp., is one of the major diseases of pepper in Brazil, causing considerable losses to crop productivity. The efficient management of the disease is hampered by the high variability of the causal agents. In Brazil, there is no knowledge of which species of Xanthomonas occurs on pepper. In this study, 59 strains of Xanthomonas spp. isolated from different pepper-producing regions of Brazil were characterized by biochemical and molecular techniques. Results showed the prevalence of X. euvesicatoria as the causal agent of bacterial spot on pepper in Brazil. © 2015 Blackwell Verlag GmbH.

Cardoso A.I.I.,Sao Paulo State University | Claudio M.T.R.,Sakata Seed Sudamerica Ltda | Nakada-Freitas P.G.,Sao Paulo State University | Magro F.O.,Prefeitura de Jundiai | Tavares A.E.B.,Sao Paulo State University
Horticultura Brasileira | Year: 2016

Considering the scarce information on nutrient extraction by plants for seed production within vegetable crops, as well as the effect of fertilization over extraction, studying nutrient accumulation in different plant parts under varied fertilization rates is necessary. This study aimed to evaluate the influence of phosphate rates on macronutrient accumulation in cauliflower plants during seed production. Five phosphate rates were studied (0, 300, 600, 900 and 1200 kg/ha P2O5), in a randomized complete block design, with four replications. Accumulation of nutrients in the different plant parts was evaluated at the end of the cycle (vegetative and reproductive, the latter divided in seeds and inflorescence). Data were submitted to analysis of variance and regression. Considering only the seeds, a quadratic effect was obtained for the accumulation of all macronutrients, with maximum estimated for rates between 858 and 952 kg/ha P2O5. Considering the whole plant (total accumulation), a linear increase for P, Ca and S was obtained the higher the P2O5 rates, while the effect was quadratic for N, K and Mg accumulation. The total nutrient accumulation descending order was: K>N>Ca>S>P>Mg, and considering only the seeds was: N>S>K>P>Ca>Mg, S being highlighted as the second most accumulated nutrient in the seeds. © 2016, Sociedade de Olericultura do Brasil. All rights reserved.

dos Santos R.L.,Sao Paulo State University | dos Santos R.L.,Sakata Seed Sudamerica Ltda | Pavan M.A.,Sao Paulo State University | da Silva N.,Sao Paulo State University | Fumes L.A.A.,University of Sao Paulo
Summa Phytopathologica | Year: 2012

The inheritance of resistance to powdery mildew in the pea cultivar MK-10 and some histological aspects of infection were assessed. For the inheritance study, F1, F2, backcrosses and F3 generations of MK-10 crossed with two susceptible populations were evaluated. Histological evaluations included percentage of germinated conidia, percentage of conidia that formed appresoria, percentage of conidia that established colonies, and number of haustoria per colony. Segregation ratios obtained in the resistance inheritance study were compared by Chi-square (x1) test and the histological data were analyzed by Tukey's test at 5% probability. It was concluded that resistance of MK-10 to powdery mildew is due to a pair of recessive alleles since it is expressed in the pre-penetration stage and completed by post-penetration localized cellular death, characteristic of the presence of the pair of recessive alleles er1er1.

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