scholarly journals Resistencia genética a la Enfermedad de la Cereza del Café en variedades cultivadas en Colombia.

2020 ◽  
pp. 68-90 ◽  
Author(s):  
Carlos Ernesto Maldonado ◽  
Lucia Ángel-Giraldo

La enfermedad de las cerezas del café (CBD), antracnosis causada por el hongo Colletotrichum kahawae subsp. kahawae, ha sido registrada solo en África y puede ocasionar pérdidas de producción hasta del 80%. Cenicafé desarrolla variedades resistentes a las enfermedades más limitantes para el cultivo, aún en ausencia de los patógenos en Colombia, usando al Híbrido de Timor (HT) como la principal fuente de resistencia a la roya del cafeto y a CBD. El propósito de este estudio fue conocer la presencia del gen Ck-1 de resistencia a CBD en las principales variedades de café cultivadas en Colombia, establecer la correlación entre la presencia de Ck-1 y la respuesta a inoculación de hipocótilos y explorar las bases genómicas de la resistencia. Los marcadores moleculares ligados a Ck-1 se ubicaron en el cromosoma 1 de Coffea canephora, región genómica con quince genes de resistencia a enfermedades. Se encontraron marcadores para Ck-1 en todas las líneas mejoradas derivadas del HT-1343 y ausentes en las variedades Típica, Borbón y Caturra, y en líneas derivadas del HT-832/1. No hubo correlación entre las formas alélicas de resistencia a CBD y la resistencia medida por inoculación de hipocótilos. La alta frecuencia de formas alélicas asociadas con resistencia a CBD en materiales seleccionados por resistencia a roya sugiere cosegregación de genes de resistencia para ambas enfermedades. La estrategia de variedades multilínea desarrolladas por Cenicafé, que actualmente corresponde a cerca del 80% del café sembrado en el país, hace que la población en general esté protegida ante la eventual llegada del patógeno a Colombia.

REVISTA FIMCA ◽  
2018 ◽  
Vol 5 (2) ◽  
pp. 28-31
Author(s):  
Darlan Darlan Sanches Barbosa Alves ◽  
Victor Mouzinho Spinelli ◽  
Marcos Santana Moraes ◽  
Carolina Augusto De Souza ◽  
Rodrigo da Silva Ribeiro ◽  
...  

Introdução: O estado de Rondônia se destaca como tradicional produtor de café, sendo o segundo maior produtor brasileiro de C. canephora. No melhoramento genético de C. canephora, a seleção de plantas de elevada peneira média está associada à bebida de qualidade superior. Objetivos: O objetivo desse estudo foi avaliar a variabilidade genética de clones de C. canephora para o tamanho dos grãos, mensurado a partir da avaliação da peneira média (PM). Materiais e Métodos: Para isso, foi conduzido ao longo de dois anos agrícolas experimento no campo experimental da Embrapa no município de Ouro Preto do Oeste-RO, para a avaliação da peneira média de 130 genótipos (clones) com características das variedades botânicas Conilon, Robusta e híbridos intervarietais. O delineamento experimental utilizado foi de blocos ao acaso, com quatro repetições de quatro plantas por parcela. Resultados: Não houve resultados significativos para a interação clones X anos, indicando uma maior consistência no comportamento das plantas ao longo do tempo. Porém foram observadas diferenças significativas para o tamanho dos grãos entre os genótipos avaliados, possibilitando selecionar genótipos superiores. Conclusão: Os genótipos agruparam-se em cinco classes de acordo com o teste de média, subsidiando a caracterização de um gradiente de variabilidade da característica avaliada ABSTRACTIntroduction: Coffea canephora accounts for approximately 35% of the world's coffee production. The state of Rondônia stands out as a traditional coffee producer, being the second largest Brazilian producer of C. canephora. In the classical genetic improvement of C. anephora, the selection of plants of high average sieve is associated with a drink of superior quality. Objectives: The objective of this udy was to evaluate the genetic variability of Coffea canephora clones for the agronomic medium sieve (PM). Materials and Methods: The experiment was conducted in the experimental field of Embrapa, municipality of OuroPreto do Oeste-RO, located at coordinates 10º44'53 "S and 62º12'57". One hundred thirty genotypes (clones) of botanical characteristics Conilon, Robusta and intervarietal hybrids were evaluated in the agricultural years 2013-2014 and 2014-2015. The experimental design was a randomized block design with four blocks and four plants per plot, spacing 3.5 x 1.5 meters between plants. Results: Significant difference was found for the grain size. According to the F test, at 5% probability, the genotypes were grouped into five classes according to the mean test. Conclusion: The results obtained subsidized the characterization of a variability gradient of the evaluated trait.


2005 ◽  
Vol 17 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Sttela Dellyzete Veiga Franco da Rosa ◽  
Delacyr da Silva Brandão Júnior ◽  
Édila Vilela de Resende Von Pinho ◽  
André Delly Veiga ◽  
Luiz Hildebrando de Castro e Silva

Desiccation tolerance in seeds depends on the species, development stage and drying conditions, especially the water removal rate. Coffea seeds are considered of intermediate performance, because they tolerate relative dehydration compared to orthodox seeds and are sensitive to low temperatures. The objective of this study was to verify the effect of different drying rates on the viability and storability of Coffea canephora seeds. A complete randomized experimental design was used, in a factorial 3 x 5 x 2 design, with three drying rates (fast, intermediate and slow), five final mean water contents after drying (51, 42, 33, 22 and 15 %) and two storage temperatures (10 and 20°C). The germination and seed vigor assessments, using radicle protrusion, cotyledon leaf opening, seedling emergence and emergence speed index, were performed shortly after drying and after two and four months storage. It was observed that with reduction in the water content there was reduction in the germination values and seed vigor, for all the drying rates. The greatest reductions in physiological quality occurred when the seeds were dried quickly and the best results were obtained at the intermediate drying rate. There was an effect of drying rate and storage temperature on the physiological quality of the seeds, and lower germination and vigor values were observed in seeds with lower water content stored at 20°C. C. canephora seeds were tolerant to desiccation down to 15 % water content and can be stored for four months at 10°C. A temperature of 20ºC can be used to store C. canephora seeds, as long as the water content is not reduced to values below 22 % water content.


Author(s):  
Rosa Elena Ibarra López ◽  
Eduardo F. Chávez Navarrete ◽  
Jimmy T. Pico Rosado ◽  
Cristian R. Subía García ◽  
Andrew J. Margenot

2020 ◽  
Vol 132 ◽  
pp. 105113
Author(s):  
E. Mangwende ◽  
P.W. Chirwa ◽  
T.A.S. Aveling

2005 ◽  
Vol 25 (3) ◽  
pp. 214-222 ◽  
Author(s):  
Vinod Kumar ◽  
K. V. Satyanarayana ◽  
S. Sarala Itty ◽  
E. P. Indu ◽  
P. Giridhar ◽  
...  

Author(s):  
Laura A. Lallemand ◽  
James G. McCarthy ◽  
Sean McSweeney ◽  
Andrew A. McCarthy

Chlorogenic acids (CGAs) are a group of soluble phenolic compounds that are produced by a variety of plants, includingCoffea canephora(robusta coffee). The last step in CGA biosynthesis is generally catalysed by a specific hydroxycinnamoyl-CoA quinate hydroxycinnamoyltransferase (HQT), but it can also be catalysed by the more widely distributed hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyltransferase (HCT). Here, the cloning and overexpression of HCT fromC. canephorainEscherichia colias well as its purification and crystallization are presented. Crystals were obtained by the sitting-drop technique at 293 K and X-ray diffraction data were collected on the microfocus beamline ID23-2 at the ESRF. The HCT crystals diffracted to better than 3.0 Å resolution, belonged to space groupP42212 with unit-cell parametersa=b= 116.1,c= 158.9 Å and contained two molecules in the asymmetric unit. The structure was solved by molecular replacement and is currently under refinement. Such structural data are needed to decipher the molecular basis of the substrate specifities of this key enzyme, which belongs to the large plant acyl-CoA-dependent BAHD acyltransferase superfamily.


2014 ◽  
Vol 33 (5) ◽  
pp. 422-431 ◽  
Author(s):  
Umberto Zottich ◽  
Maura Da Cunha ◽  
Germana B. Dias ◽  
Guilherme R. Rabelo ◽  
Antonia Elenir A. Oliveira ◽  
...  

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