Maria Amélia Gava Ferrão

Differentially expressed genes and proteins upon drought acclimation in tolerant and sensitive genotypes of Coffea canephora

The aim of this study was to investigate the molecular mechanisms underlying drought acclimation in coffee plants by the identification of candidate genes (CGs) using different approaches. The first approach used the data generated during the Brazilian Coffee expressed sequence tag (EST) project to select 13 CGs by an in silico analysis (electronic northern). The second approach was based on screening macroarrays spotted with plasmid DNA (coffee ESTs) with separate hybridizations using leaf cDNA probes from drought-tolerant and susceptible clones of Coffea canephora var. Conilon, grown under different water regimes. This allowed the isolation of seven additional CGs. The third approach used two-dimensional gel electrophoresis to identify proteins displaying differential accumulation in leaves of drought-tolerant and susceptible clones of C. canephora. Six of them were characterized by MALDI-TOF-MS/MS (matrix-assisted laser desorption-time of flight-tandem mass spectrometry) and the corresponding proteins were identified. Finally, additional CGs were selected from the literature, and quantitative real-time polymerase chain reaction (qPCR) was performed to analyse the expression of all identified CGs. Altogether, >40 genes presenting differential gene expression during drought acclimation were identified, some of them showing different expression profiles between drought-tolerant and susceptible clones. Based on the obtained results, it can be concluded that factors involved a complex network of responses probably involving the abscisic signalling pathway and nitric oxide are major molecular determinants that might explain the better efficiency in controlling stomata closure and transpiration displayed by drought-tolerant clones of C. canephora.

Parâmetros genéticos em café Conilon

O objetivo deste trabalho foi avaliar a produtividade e obter as estimativas de parâmetros geneticos e nao geneticos de 40 materiais geneticos do programa de melhoramento genetico de cafe Conilon do Incaper, no Estado do Espirito Santo. Foram analisados dados de dois experimentos, nos municipios de Marilândia e Sooretama, ES, nas safras de 1996, 1997, 1998, 1999, 2000, 2001 e 2002, em que se avaliaram 16 caracteristicas. Realizou-se, inicialmente, a analise de variância individual, por local em cada ano, com base na media de parcelas, em blocos ao acaso. Posteriormente foi feita a analise de variância conjunta. Os genotipos apresentaram grande variabilidade genetica para a maioria das caracteristicas avaliadas. Os elevados coeficientes de determinacao genotipico e coeficientes de variacao geneticos, associados as altas produtividades e a variabilidade genetica indicam a possibilidade de obtencao de exitos em programas de melhoramento genetico para diferentes caracteristicas avaliadas nos dois municipios.

Divergência genética em café conilon

O objetivo deste trabalho foi avaliar a divergencia genetica entre 32 clones de cafe conilon ( Coffea canephora Pierre ex Frohener) componentes de tres variedades clonais melhoradas, com vistas a identificacao dos mais dissimilares, para o estabelecimento de programas de cruzamentos dirigidos. A divergencia genetica foi avaliada por procedimentos multivariados: distância generalizada de Mahalanobis, metodo de agrupamento de otimizacao de Tocher e tecnica de variaveis canonicas. Sete caracteres foram avaliados em experimento conduzido em Marilândia, ES. Os genotipos ES 92, ES 25 e ES 22 sao os mais divergentes, sendo os dois ultimos os mais indicados para cruzamento com os demais, tendo em vista aliarem divergencia genetica a um bom desempenho produtivo.

Resposta fisiológica de clone de café Conilon sensível à deficiência hídrica enxertado em porta-enxerto tolerante

The objective of this work was to determine alterations in physiology and those due to drought tolerance on Conilon coffee (Coffea canephora) contrasting clones regarding the sensitivity to hydric stress. The reciprocal grafting between clones 109A, drought sensitive, and 120, drought tolerant, - 120/109A, 120/120, 109A/120, 109A/109A - along with their ungrafted control plants (109A and 120) were evaluated. Plants were cultivated in 12‑L vases in greenhouse. Six months after grafting, half of the plants was subjected to water deficit, by suspending irrigation until leaves reached the hydric potential of ‑3,0 MPa. When clone 120 was used as rootstock, plants presented deeper roots, although with lower root-biomass, higher ability to postpone leaf dehydration and higher instantaneous water‑use efficiency (WUE). Under severe drought, starch and sucrose contents decreased similarly, regardless of the treatment, whereas leaf concentrations of glucose, fructose, total amino acids and proline were higher in non‑grafted 109A, 109A/109A, and 120/109A plants. These plants showed the lowest WUE values. Solute accumulation was not primarily related to drought tolerance. The use of drought tolerant rootstocks improves to drought tolerance in coffee.

Adaptabilidade e estabilidade via regressão não paramétrica em genótipos de café

The objective of this work was to evaluate a methodology of phenotypic adaptability and stability analyses of coffee genotypes based on nonparametric regression. The technique used differs from other techniques because it reduces the influence of extreme points resulting from the presence of genotypes whose answers to a certain environment are too different on the estimation of the adaptability parameter. Data from an experiment studying the average yield of 40 coffee (Coffea canephora) genotypes in a randomized block design with six replicates were used to evaluate the method. The genotypes were evaluated along five years (1996, 1998, 1999, 2000 and 2001) in two locations (Sooretama and Marilândia, ES, Brazil), in a total of ten environments. The methodology proposed proved adequate and efficient, since it eliminates the disproportionate effects induced by the presence of extreme points and avoids misleading recommendations of genotypes in terms of adaptability.

Divergência genética em feijoeiro em condições de inverno tropical

This work aimed to evaluate the genetic divergency among tolerants and non tolerants parents to cold and their hybrid combinations. The generalized distance of Mahalanobis, the method of cluster analysis proposed by Tocher and the canonical variability technic were the multivaried proce- dures used. Common bean cultivars of two different groups were used in the crosses, being Vermelho 2157, Ouro Negro, Antioquia 8 and Ricopardo 896 the cultivars tolerant to cold, and the commercial cultivars EMCAPA 404 - Serrano, Carioca and EMCAPA 405 - Goytacazes the non tol- erant ones. The parents and the hybrid combinations in the F 1, F2 and F3 generations were evaluated in Coimbra, Minas Gerais on four experiments, in 1995 and 1996. The genetic divergency among the genetic resources evaluated were influenced by temperature and advancement of the generations. The most dissimilar cultivars were Antioquia 8 and EMCAPA 404 - Serrano and Ouro Negro and Ricopardo 896 were the most similar cultivars. Grain yield and number of pods per plot were the less important characteristics influencing on genetic divergency. However, as they showed low genotypic correlation with the other characteristics and were of the greatest importance on yield, they can not be despised.

Molecular characterization of arabica and Conilon coffee plants genotypes by SSR and ISSR markers

The molecular characterization of ten genotypes of the Coffea arabica plants and of seven genotypes of C. canephora having interesting features for coffee breeding programs was carried to select the parents for breeding. A total of 40 SSR and 29 ISSR primers were used. The primers generated a total of 331 (307 polymorphic and 24 monomorphic) bands. Analysis of genetic diversity presented dissimilarity intervals ranging from 0.22 to 0.44 between the Conilon genotypes, from 0.02 to 0.28 between the Arabica genotypes, and from 0.49 to 0.60 between the genotypes of the two species in the joint analysis. Four groups were formed: I = genotypes of C. arabica, II = four progenies of C. canephora, Conilon group, and one non defined C. canephora (Conilon or Robusta), III = one progeny of un-defined C. canephora (Conilon or Robusta) and IV = one progeny of C. canephora of Robusta group. The grouping formed was consistent with the origins of each group. High stabilities of the bifurcations were found by bootstrap analysis. The use of molecular markers of the SSR and ISSR types in the diversity study was efficient in distinguishing genotypes between and within C. arabica and C. canephora.

A mixed model to multiple harvest-location trials applied to genomic prediction in Coffea canephora

Genomic selection (GS) has been studied in several crops to increase the rates of genetic gain and reduce the length of breeding cycles. Despite its relevance, there are only a modest number of reports applied to the genus Coffea. Effective implementation depends on the ability to consider genomic models, which correctly represent breeding scenario in which the species are inserted. Coffee experimentation, in general, is represented by evaluations in multiple locations and harvests to understand the interaction and predict the performance of untested genotypes. Therefore, the main objective of this study was to investigate GS models suitable for use in Coffea canephora. An expansion of traditional GBLUP was considered and genomic analysis was performed using a genotyping-by-sequencing (GBS) approach, showed good potential to be used in coffee breeding programs. Interactions were modeled using the multiplicative mixed model theory, which is commonly used in multi-environment trials (MET) analysis in perennial crops. The effectiveness of the method used was compared with other genetic models in terms of goodness-of-fit statistics and prediction accuracy. Different scenarios that mimic coffee breeding were used in the cross-validation process. The method used had the lowest AIC and BIC values and, consequently, the best fit. In terms of predictive ability, the incorporation of the MET modeling showed higher accuracy (on average 10–17% higher) and lower prediction errors than traditional GBLUP. The results may be used as basis for additional studies into the genus Coffea and can be expanded for similar perennial crops.

COMPORTAMENTO DE PLANTAS DE CAFÉ ARÁBICA SUBMETIDAS A DÉFICIT HÍDRICO DURANTE O DESENVOLVIMENTO INICIAL

O presente trabalho objetivou estudar a influencia do deficit hidrico no desenvolvimento inicial da lavoura cafeeira, aplicado em diferentes epocas: 30, 60, 90 e 120 dias apos o transplantio. O experimento foi conduzido em casa de vegetacao, em delineamento inteiramente ao acaso, com cinco tratamentos e tres repeticoes. Os tratamentos consistiram na submissao das mudas transplantadas a deficits hidricos com duracao fixa de 30 dias, sendo D0 = sem deficit hidrico; D1 = plantas submetidas a deficit hidrico entre o 30o e 60o dia apos o transplantio; D2 = plantas submetidas a deficit hidrico entre o 60o e 90o dia apos o transplantio; D3 = plantas submetidas a deficit hidrico entre o 90o e 120o dia apos o transplantio e; D4 = plantas submetidas a deficit hidrico entre o 120o e 150o dia apos o transplantio. Apos 180 dias do transplantio avaliou-se a massa seca da parte aerea e do sistema radicular, a area foliar, o diâmetro da copa e altura das plantas. O efeito do deficit hidrico foi especialmente importante nas variaveis estudadas quando aplicado aos 30, 60 ou 90 dias apos o transplantio e nao influenciou de forma significativa as variaveis area foliar, diâmetro da copa e altura das plantas, quando aplicado aos 120 dias apos o transplantio.

Reaction of Cultivar Coffee 'Vitória INCAPER 8142' of Cornillon to Parasitism of Meloidogyne exigua

ABSTRACT Among factors limiting to the yield of the coffee crop are the diseases, deserving prominence the nematode Meloidogyne exigua . The objective of this work was to assess the level of resistance of 13 clones (1V, 2V, 3V, 4V, 5V, 6V, 7V, 8V, 9V, 10V, 11V, 12V and 13V) wich composes the clonal variety ‘Vitoria INCAPER 8142’ of conilon coffee ( Coffea canephora Pierre), to M. exigua . The 13 clones and more one control ( C. arabica , cv. Catuai IAC-44) were inoculated with 7,000 individuals of M. exigua . After 180 days of inoculation, the final population of nematodes per root system was determined. For determination of the resistance levels, both the reproduction factor and the reduction of the reproduction factor were considered. The variety ‘Vitoria INCAPER 8142’ presented clones with different levels of resistance. Clones 1V, 4V, 7V, 9V and 12V behaved as susceptible or efficient host and the other clones were resistant or non-efficient host. Key words: Coffea canephora, clones, robust coffee, resistance, root-knot nematode.