scholarly journals Agronomic characterization and responses to coffeeleaf rust in coffee progenies resistant to the gall nematode Meloidogyne exigua

2017 ◽  
Vol 38 (2) ◽  
pp. 671
Author(s):  
Ramiro Machado Rezende ◽  
Gladyston Rodrigues Carvalho ◽  
Alex Mendonça de Carvalho ◽  
Antonio Nazareno Mendes ◽  
Sônia Maria Lima Salgado ◽  
...  

The aim of this study was to determine agronomic characteristics and responses to the coffee leaf rust fungus (Hemileia vastatrix Berk. et Br.) in coffee progenies resistant to the gall nematode Meloidogyne exigua. The experiment was conducted in December 2000 at Ouro Verde Farm (FazendaOuro Verde), located in the municipality of Campos Altos – Minas Gerais (MG). Ten F3:4 progenies were evaluated. They were derived from crosses between CIFC 2570 Timor Hybrid selections and Catuaí cultivars known to be resistant to M. exigua. The Catuaí Vermelho IAC 99 cultivar served as a control. A randomized block design with three replicates was used. In total, there were thirty-three plots consisting of eight plants each. The following characteristics were assessed between the harvests of 2011/2012 and 2014/2015: (a) yield expressed as processed coffee bags ha-1; (b) rust incidence and severity; (c) vegetative vigor; (d) percentage of coffee fruits at the “cherry” stage; (e) percentage of floaters; (f) crown diameter; (g) percentage of coffee beans of size sieve 17 and higher; and (h) sensory analysis of the coffee beverage. The results indicated the following: (a) the H514-7-14-2, H514-7-4-5, H493-1-2-2, H514-7-16-3, H514-7-8-11, H518-2-10-1, and H514-5-2-4 progenies were the most productive; (b) all progenies showed promising resistance to coffee leaf rust; (c) all genotypes had the potential for specialty coffee production; (d) the H493-1-2-2 progeny showed resistance both to rust and the nematode, and has good potential for specialty coffee production; and (e) the yields of the H514-7-8-11, H518-2-10-1, H514-5-2-4, H514-7-16-3, H514-7-14-2, H514-7-4-5, and H493-1-2-2 progenies were significantly higher than that of the Catuaí IAC 99 control.

2021 ◽  
Vol 748 (1) ◽  
pp. 012002
Author(s):  
Sabam Malau ◽  
Albiner Siagian ◽  
Maria Rumondang Sihotang

Abstract Coffee is now experiencing a serious threat from fungus Hemileia vastatrix which caused epidemic of rust disease in America, Africa, and Asia. As solution, the use of resistant cultivars is the best way. However, interaction between genotype and environment can change the rank of genotypes that shows instability of these genotypes against leaf rust. Purpose of this research was to study stability of genotypes of Arabica coffee against coffee leaf rust. A field experiment was arranged as factorial randomized complete block design with 2 factors (genotypes and climate zones) with three replication. The observed parameters were branch rust incidence, leaf rust incidence, and leaf rust severity. This research result showed significant genotype x environment interaction in all variables. Length of dry season is the most important factor affecting coffee leaf rust because it had the highest correlation coefficient with leaf rust severity (r = 0.662**). Less length of dry season should be the first criteria for selection of coffee farms. The most desired genotype was G7 which performed low leaf rust severity (7.71%) and had a stable resistance indicated by the same leaf rust severity in all environments and 6 SMg. Due to the significant interaction between genotypes and the environment, the genotype to be planted in a region must be tested in that region first.


Botany ◽  
2010 ◽  
Vol 88 (7) ◽  
pp. 621-629 ◽  
Author(s):  
Helena Gil Azinheira ◽  
Maria do Céu Silva ◽  
Pedro Talhinhas ◽  
Clara Medeira ◽  
Isabel Maia ◽  
...  

Leaf rust, caused by Hemileia vastatrix Berk & Broome, is the most destructive fungal disease of coffee. In the absence of a suitable gene validation system in coffee, the objective of this study was to investigate whether the model plant Arabidopsis thaliana (L.) Heynh. may be used as a heterologous system for the molecular dissection of coffee responses to leaf rust. Histological examination of A. thaliana (Col-0) leaves inoculated with H. vastatrix (race II) showed that by 24 h after inoculation (hai), H. vastatrix uredospores differentiated appressoria and penetrated the stomata, but failed to form haustoria. Arabidopsis thaliana cellular resistance responses included hypersensitive-like response (HR) of stomata guard cells together with accumulation of phenolic compounds and callose deposition in walls of epidermal and mesophyll cells. Results indicate that H. vastatrix infection triggered the induction of a set of defence-related genes peaking at 18 and 42 hai. The non-host HR triggered by H. vastatrix in the model plant A. thaliana makes it usable to infer the function of coffee genes involved in pre-haustorial rust resistance.


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.


IMA Fungus ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Adans A. Colmán ◽  
Harry C. Evans ◽  
Sara S. Salcedo-Sarmiento ◽  
Uwe Braun ◽  
Kifle Belachew-Bekele ◽  
...  

AbstractDigitopodium hemileiae was described originally in 1930 as Cladosporium hemileiae; growing as a mycoparasite of the coffee leaf rust (CLR), Hemileia vastatrix, in a sample of diseased leaves of Coffea canephora collected in the Democratic Republic of Congo. No cultures from this material exist. More recently, the type material was re-examined and, based on morphological features, considered to be incorrectly placed in Cladosporium. The new genus Digitopodium was erected to accommodate this species. Interest in fungal antagonists of H. vastarix, as potential biocontrol agents of CLR, led to comprehensive surveys for mycoparasites, both in the African centre of origin of the rust, as well as in its South American exotic range. Among the rust specimens from Ethiopia, one was found to be colonized by a fungus congeneric with, and similar to, D. hemileiae. Pure cultures obtained from the Ethiopian material enabled a molecular study and for its phylogenetic position to be elucidated, based on DNA sequence data from the ITS and LSU regions. Molecular data showed that two members of the recently erected genus Hyalocladosporiella (Herpotrichiellaceae: Chaetothyriales) are congeneric with Digitopodium from Ethiopia and morphologically similar to both D. hemileiae and the two Ethiopian isolates. These isolates were found to be morphologically and genetically identical to H. tectonae, described previously from Brazil. Thus, species of Hyalocladosporiella are re-allocated to Digitopodium here; including D. tectonae, and a novel species, D. canescens, recently found in Brazil growing as a mycoparasite of Puccinia thaliae. The potential use of D. hemileiae and D. tectonae for classical biological control of CLR is discussed.


2006 ◽  
Vol 6 (1) ◽  
pp. 52-58
Author(s):  
Cipta Ginting

Germination of Hemileia vastatrix uredospores on crude water extracts of zinger and turmeric rhizome and clove and Piper betle leaves.  Coffee leaf rust caused by H. vastatrix especially on Arabica coffee is one of most important diseases in coffee and conventional control methods of leaf coffee rust is still unsatisfactory.  The objective of this study was to determine the effect of crude water extract on the germination of H. vastatrix uredospores.  The study was conducted from January to September 2004 in the Laboratory of Plant Pathology at Unila.  In each test, treatments were arranged in a randomized complete block design with four replications.  Crude water extract was prepared by homogenizing 100 g of material in 100 ml sterilized distilled water.  After being passed through four layers of sterilized cheesecloth, the mixture was defined as the aliquot (100% extract) and dilutions were made with sterile distilled water to obtain concentrations of 2.5 to 10%.  Each of four materials (zinger, turmeric, clove, and Piper betle) was tested separately in five aliquot concentration levels.  One ml of each extract was mixed with 0.25 ml of uredospora suspension (4 x 105 per ml), and 0.2 ml of the mixture was incubated.  The variable was germinated uredospora (%) that was determined under a mikroscope.  The results show that significant reduction in spore germination occurred by  turmeric, clove, and P. betle extracts at > 2.5% and by zinger extract at > 5%.  Some uredospora exposed to plant extract germinated abnormally:  germ tubes shorten, swollen, or malform.


Author(s):  
D. S. Ferreira ◽  
J. F. T. do Amaral ◽  
L. L. Pereira ◽  
J. M. S. Ferreira ◽  
R. C. Guarçoni ◽  
...  

Abstract The production of specialty coffee has several factors and parameters that are added up in the course of production, so that the quality is expressed in the act of consumption. Based on this scenario, this study included the analysis of ten genotypes of arabica coffee, the materials being subjected to irrigated and rainfed water regimes, in a low altitude region, to identify responses for sensory and physical–chemical quality. The genotypes were evaluated in a split-plot scheme with a randomized block design, with three replications. Arabica coffee fruits were harvested with 80% cherry seeds and processed by the wet method. Subsequently, the characteristics related to physical–chemical and sensory analyses were evaluated. The genotypes of the Paraíso group showed great variability for the physical–chemical and sensory variables for rainfed and irrigated regimes. The genotypes of the Catuaí group, however, showed less variability for sensory characteristics in both cultivation environments and for physical–chemical characteristics in the irrigated regime. In the sensorial data set, the genotypes Catuaí 144 CCF and Catuaí 144 SFC (when irrigated) and Paraíso H 419-3-3-7-16-2, Paraíso H 419-3-3-7-16-11 and Catucaí 24-137 (rainfed cultivation), are more favourable to the production of specialty coffee at low altitude.


2017 ◽  
Vol 14 (6) ◽  
pp. 1-8
Author(s):  
R Mudyiwa ◽  
N Mwatsiya ◽  
B Manenji ◽  
P Chidoko ◽  
C Mahoya

Allergy ◽  
2001 ◽  
Vol 56 (7) ◽  
pp. 684-687 ◽  
Author(s):  
M. A. Croce Portocarrero ◽  
E. Rosa da Costa Manso ◽  
W. Gambale ◽  
L. Takayama ◽  
C. E. Oliveira Andrade ◽  
...  

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