Arquivos do Instituto Biológico

URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/13097

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Resultados da Pesquisa

Agora exibindo 1 - 3 de 3
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    Multiple resistance to bacterial halo blight and bacterial leaf spot in Coffea spp.
    (Instituto Biológico, 2019) Rodrigues, Lucas Mateus Rivero; Destéfano, Suzete Aparecida Lanza; Almeida, Irene Maria Gatti de; Beriam, Luís Otávio Saggion; Braghini, Masako Toma; Guerreiro Filho, Oliveiro
    Breeding for genetic resistance is an important method of crop disease management, due to the numerous benefits and low cost of establishment. In this study, progenies of 11 Coffea species and 16 wild C. arabica accessions were tested for their response to Pseudomonas syringae pv. garcae, the causal agent of bacterial halo blight, a widespread disease in the main coffee-producing regions of Brazil and considered a limiting factor for cultivation in pathogen-favorable areas; and also to P. syringae pv. tabaci, causal agent of bacterial leaf spot, a highly aggressive disease recently detected in Brazil. Separate experiments for each disease were carried out in a greenhouse, with artificial pathogen inoculations and ideal moisture conditions for disease development. The results showed that C. canephora, C. congensis, C. eugenioides, C. stenophylla, and C. salvatrix progenies, the wild C. arabica accessions Dilla & Alghe and Palido Viridis, and cultivar IPR 102 contain satisfactory levels of simultaneous resistance against bacterial halo blight and bacterial leaf spot. These results are useful in breeding programs for durable resistance to multiple biotic agents, providing new combinations of resistance alleles by hybridization, as well as for phytopathological studies, to identify infraspecific variability of the pathogens.
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    Can the leaf age influence the susceptibility to bacterialleaf- spot and bacterial-halo-blight on coffee seedlings?
    (Instituto Biológico, 2018) Tomiyama, Ana Laura Midori Rossi; Rodrigues, Lucas Mateus Rivero; Andrade, Vinicius Teixeira; Beriam, Luis Otavio Saggion; Destéfano, Suzete Aparecida Lanza; Guerreiro Filho, Oliveiro
    Pseudomonas syringae van Hall, 1902, causes yield losses in innumerous economic important crops. On coffee trees, P. syringae pv. garcae causes the bacterial-halo-blight (BHB) and P. syringae pv. tabaci the bacterial-leaf-spot (BLS). Recently, these diseases incidence has increase in occurrence areas and aggressiveness in Brazil. Although leaf age plays a role in the severity response of BHB, it is not known yet if this phenomenon also occurs in coffee-BLS interaction, and with highly virulent strains. So, we examined differences in the diseases severity by inoculation of P. syringae pv. garcae and P. syringae pv. Tabaci strains on coffee leaves with different ages, to compare this aspect with coffee-BLS interaction. Our results showed that, for both pathovars, the severity was greater at the first internodes leaves, although for the most aggressive strains it was quite similar on any leaf age.
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    Diferenciação de bactérias do gênero Pseudomonas patogênicas ao cafeeiro por técnicas serológicas
    (Instituto Biológico, 2017) Beriam, Luis Otavio Saggion; Patrício, Flavia Rodrigues Alves; Maciel, Karen Wolf; Rodrigues, Lucas Mateus Rivero; Almeida, Irene Maria Gatti de
    Há várias bactérias que causam problemas para o cafeeiro, incluindo Pseudomonas cichorii, P. syringae pv. garcae, P. syringae pv. tabaci, Burkholderia andropogonis e Xylella fastidiosa, todas elas já descritas no Brasil. Tentativas de diferenciar essas bactérias por testes serológicos de dupla difusão em ágar (dda), com antissoros produzidos contra células íntegras de P. s. pv. garcae, mostraram reações cruzadas, principalmente entre P. s. pv. garcae e P. s. pv. tabaci. Dessa forma, foram produzidos antissoros contra P. s. pv. garcae (linhagem patotipo IBSBF-248 — Coleção de Culturas de Fitobactérias do Instituto Biológico — IBSBF), obtidos por meio de imunizações de coelhos com antígenos de proteínas do complexo proteico da membrana (CPM). Esses antissoros foram testados por dupla difu são em agarose (dda) contra diversas formas de antígenos extraídos de P. cichorii, P. s. pv. garcae e P. s. pv. tabaci [células autoclavadas, células tratadas com formol, exopolissacarídeos (EPS), glicoproteí nas (GP) da cápsula bacteriana, proteínas de membrana e suspen são bacteriana (SB) em NaCl 0,85%]. Os resultados mostraram que, dependendo do antígeno e do meio suporte da dupla difusão (com ou sem MgCl2 e/ou azul de tripano), os antissoros reagem somente com P. s. pv. garcae. Desse modo, esses antígenos podem ser usados para a rápida diagnose da mancha aureolada do cafeeiro nos testes de dda.