Risk analysis of climate change on black sigatoka in banana in Brazil.

2008

Detection and molecular characterization of Grapevine yellow speckle viroid 1 isolates infecting grapevines in Brazil.

Abstract Presently, Hop stunt viroid(HSVd) and Citrus exocortis viroid (CEVd) are the only viroids reported to infect grapevines (Vitis spp.) in Brazil, among the seven viroid species already reported infecting this host in other countries. All grapevine viroid diseases are graft-transmissible and can induce losses especiallywhenassociatedwithviruses.Theaimofthisworkwas to confirm infection by Grapevine yellow speckle viroid 1(GYSVd-1) in grapevine samples exhibiting yellow speckle symptoms in the leaves and in asymptomatic samples sequenced by next generation sequencing (NGS). The occurrence of this viroid in Brazil was further investigated in a second study. Total RNAs and dsRNAs were extracted from five symptomatic plants and 16 asymptomatic samples, respectively. Specific primers were used for RT-PCR and amplified DNA fragments were cloned and sequenced by the Sanger method. Eleven complete nucleotide sequences of GYSVd-1 isolates (366 ?367 nt) were obtained from NGS and from RT-PCR amplicons. Comparisons showed high identities (95.9 ?100 %) among ten isolates and an identity of 87.2 ?90.4 % with a divergent isolate (RM-BR). Phylogenetic analyses placed GYSVd-1 isolates in four clusters (types 1, 2, 3 and 4). All GYSVd-1 infections were confirmed by conventional RT-PCR and RT-qPCR using specific oligonucleo-tides and a labeled probe. This is the first report and molecular characterization of GYSVd-1 infecting grapevines in Brazil, and our survey indicates that this viroid could be widespread in the major grape producing regions of Brazil. Keywords GYSVd-1 . Incidence . Next generation sequencing. Secondary structure. Vine.

Efeito do hidrolisado de peixe no controle de Fusarium em crisântemo.

2008

Potencial de Lecanicillium longisporum no controle do oídio da abobrinha.

2008

Óleo de nim (Azadirachta indica) estimula o crescimento micelial de agentes de biocontrole.

2008

Comunidade de leveduras do fitoplano de lírio originário de produção convencional e integrada dos problemas fitossanitários.

2008

Avaliação de isolados de Trichoderma sp. e Clonostachys rosea selecionados para o controle biológico de mofo-branco como agentes promotores de crescimento em feijoeiro.

2008

Genetic structure and mating type analysis of the Pyricularia oryzae population causing widespread epidemics in southern Brazil.

Blast is a major disease of rice in Brazil, the largest rice-producing country outside Asia. This study aimed to assess the genetic structure and mating-type frequency in a contemporary Pyricularia oryzae population, which caused widespread epidemics during the 2012/13 season in the Brazilian lowland subtropical region. Symptomatic leaves and panicles were sampled at flooded rice fields in the states of Rio Grande do Sul (RS, 34 fields) and Santa Catarina (SC, 21 fields). The polymorphism at ten simple sequence repeats (SSR or microsatellite) loci and the presence of MAT1-1 or MAT1-2 idiomorphs were assessed in a population comprised of 187 isolates. Only the MAT1-2 idiomorph was found and 162 genotypes were identified by the SSR analysis. A discriminant analysis of principal components (DAPC) of SSR data resolved four genetic groups, which were strongly associated with the cultivar of origin of the isolates. There was high level of genotypic diversity and moderate level of gene diversity regardless whether isolates were grouped in subpopulations based on geographic region, cultivar host or cultivar within region. While regional subpopulations were weakly differentiated, high genetic differentiation was found among subpopulations comprised of isolates from different cultivars. The data suggest that the rice blast pathogen population in southern Brazil is comprised of clonal lineages that are adapting to specific cultivar hosts. Farmers should avoid the use of susceptible cultivars over large areas and breeders should focus at enlarging the genetic basis of new cultivars.

Adubação nitrogenada foliar e incidência da podridão parda (Monilinia fructicola) em pêssegos da cultivar 'Chimarrita'.

2011

Adubação orgânica e as consequências na podridão parda (Monilinia fructicola) em pêssegueiros da cultivar 'chimarrita'.

2011

Avaliação agronômica de videiras infectadas por vírus.

2011

Inativação térmica do crescimento micelial de Cylindrocarpon destructans.

2011

Atividade fungitóxica de produtos alternativos sobre Elsinoe ampelina.

2011

A black foot extract can delay downy mildew progress in grapevine under greenhouse conditions.

2011

Boro, aplicação foliar e conseqüências na podridão parda (Monilinia fructicola) em pêssegos da cultivar 'Chimarrita'.

2011