ABSTRACT
The aim of this study was to characterize Meloidogyne paranaensis populations collected from infested coffee crops. Methodologies used to characterize the 11 studied populations from municipalities in Paraná and Minas Gerais States involved the morphological analysis of perineal patterns, biochemical analysis by isozyme electrophoresis, sequencing of internal transcribes spacer 1 (ITS-1) and D2/D3 ribosomal DNA (rDNA) regions, reproductive fitness, and virulence characterization in coffee genotypes. Morphological evaluations showed the existence of variation between populations, although the majority of them showed typical perineal patterns. The biochemical identification was based on α-esterase isozyme analyses and resulted in the appearance of three distinct profiles: P1 (typical), P2 (atypical), and a nondescribed profile, P2b. BLAST of the ITS-1 and D2/D3 rDNA regions indicated homology (>95%) with other sequences deposited in GenBank. For reproductive fitness and virulence characterization, 13 coffee genotypes (5 Coffea arabica and 8 C. canephora) were inoculated with 11 M. paranaensis populations. Variation in the reproductive fitness of populations was observed for cultivar Mundo Novo, a genotype without resistance genes, and variation in the virulence of populations was observed in genotypes carrying resistance genes. Three populations exhibited virulence combined with high reproductive fitness, while one showed virulence with low reproductive fitness. Some hosts were resistant to 11 populations, while one of the hosts was resistant to only one population, indicating the presence of different resistance genes. Nevertheless, no relationship was observed between the origin of population and their variations in perineal patterns, esterase profiles, phylogeny, or reproductive fitness in coffee genotypes, or between the different characterizations, although differences were observed within each characteristic.
Subject(s)
Tylenchoidea , Animals , Coffee/chemistry , DNA, Ribosomal , Esterases , Genetic Fitness , Genotype , Isoenzymes , Virulence/geneticsABSTRACT
Coffee is one of the most important crops for developing countries. Coffee classification for trading is related to several factors, including grain size. Larger grains have higher market value then smaller ones. Coffee grain size is determined by the development of the perisperm, a transient tissue with a highly active metabolism, which is replaced by the endosperm during seed development. In this study, a proteomics approach was used to identify differentially accumulated proteins during perisperm development in two genotypes with regular (IPR59) and large grain sizes (IPR59-Graudo) in three developmental stages. Twenty-four spots were identified by MALDI-TOF/TOF-MS, corresponding to 15 proteins. We grouped them into categories as follows: storage (11S), methionine metabolism, cell division and elongation, metabolic processes (mainly redox), and energy. Our data enabled us to show that perisperm metabolism in IPR59 occurs at a higher rate than in IPR59-Graudo, which is supported by the accumulation of energy and detoxification-related proteins. We hypothesized that grain and fruit size divergences between the two coffee genotypes may be due to the comparatively earlier triggering of seed development processes in IPR59. We also demonstrated for the first time that the 11S protein is accumulated in the coffee perisperm.
Subject(s)
Coffea/chemistry , Plant Proteins/metabolism , Seeds/growth & development , Coffea/growth & development , Coffea/metabolism , Coffee/chemistry , Electrophoresis, Gel, Two-Dimensional , Mass Spectrometry , Plant Proteins/chemistry , Proteomics , Seeds/chemistry , Seeds/metabolismABSTRACT
The objective of the study was to evaluate the resistance to rust in coffee cultivars developed by research institutes of Brazil in Paraná state. Resistance to the local leaf rust races was assessed in high disease intensity field conditions at Londrina and Congonhinhas in 2009 and 2010.The cultivars were developed by the EPAMIG/UFV, IAPAR, IAC and MAPA/Procafé. The resistant standard 'IAPAR 59' and the susceptible standards Catuaí Vermelho IAC 144' and 'Bourbon Amarelo' were used. A randomized block design with three replications and plots with 10 plants was used. A scale from 1 to 5 based on the rust intensity was used to evaluate the resistance. The Catiguá MG 1, Catiguá MG 2, IAPAR 59, IPR 98, IPR 104, Palma II, Paraíso H-419-10-6-2-5-1, Paraíso H-419-10-6-2-10-1, Paraíso H-419-10-6-2-12-1, Pau Brasil MG 1 and Sacramento MG 1 cultivars presented complete resistance to rust at Londrina and Congonhinhas. The cultivars derived from the Catucaí germplasm were susceptible or showed different levels of partial resistance. Partial resistance to the rust was observed in several coffees derived from "Hibrido de Timor". 'Acauã' and 'Obatã IAC 1669-20' presented complete resistance at Londrina, but at Congonhinhas, they were partially resistant, indicating that different rust races have occurred at these two locations.
ABSTRACT
The genus Coffea possesses about 100 species, and the most economically important are Coffea canephora and Coffea arabica. The latter is predominantly self-compatible with 2n = 4x = 44, while the others of the genus are diploid with 2n = 2x = 22 and mostly self-incompatible. Studies using molecular markers have been useful to detect differences between genomes in Coffea; however, molecular and cytogenetic studies have produced only limited information on the karyotypes organization. We used DOP-PCR to isolate repetitive elements from genome of Coffea arabica var. typica. The pCa06 clone, containing a fragment of 775 bp length, was characterized by sequencing and used as a probe in chromosomes of C. arabica and six other species: C. canephora, Coffea eugenioides, Coffea kapakata, Coffea liberica var. dewevrei, Coffea racemosa, and Coffea stenophylla. This insert shows similarities with a gag protein of the Ty3-gypsy-like super-family. Dot blot and FISH analyses demonstrated that pCa06 is differentially accumulated between species and chromosomes. Signals appeared scattered and clustered on the chromosomes and were also associated with heterochromatic regions. While the literature shows that there is a high karyotype similarity between Coffea species, our results point out differences in the accumulation and dispersion of this Ty3-gypsy-like retrotransposon during karyotype differentiation of Coffea.
Subject(s)
Coffea/genetics , Genome, Plant , Retroelements , Chromosomes, Plant , In Situ Hybridization, Fluorescence , Karyotype , Species SpecificityABSTRACT
The aim of this study was to evaluate the coffee germplasm of the Paraná Agronomic Institute (IAPAR) for resistance to the coffee-berry-borer. Preliminary field evaluation was performed in August 2004 and the fruits of less damaged genotypes in the field were evaluated under controlled condition with obligated and free choice experiments established in a randomized complete design with three replications. The genotypes were evaluated fifteen days after infestation with one borer per fruit in Petri dishes. The data were analyzed by the Scott-Knott means test at 1 percent and by the χ2 test. Statistical analysis indicated that Coffea kapakata, Psilanthus bengalensis, C. eugenioides and genotypes with C. eugenioides genes were resistant. These genotypes presented low frequency of bored grains. C. eugenioides and C. kapakata could present resistance at epicarp level but not in the grain. P. bengalensis could present resistance also in the grains.
O objetivo deste trabalho foi identificar fontes de resistência genética a H. hampei em diferentes espécies de café do banco de germoplasma do Instituto Agronômico do Paraná (IAPAR), Londrina, PR. Foram realizadas avaliações preliminares de campo, para posterior testes de confinamento e de livre escolha, em laboratório, instalados em delineamento inteiramente casualizado com três repetições. Os genótipos foram avaliados quinze dias após a infestação com uma broca por fruto em placas de petri. Os dados foram analisados pelo teste de médias Scott-Knott a 1 por cento e pelo teste de χ2. Foi observado que C. eugenioides, C. kapakata e P. bengalensis constituem importantes fontes de resistência à broca, pois apresentaram menor freqüência de grãos brocados. Os dois primeiros podem apresentar substâncias voláteis antagônicas à broca na casca e a resistência de P. bengalensis pode estar também no grão.
ABSTRACT
Objetivou-se, neste trabalho, identificar progênies de Coffea arabica cv. IPR 100 com resistência ao nematóide Meloidogyne incognita raça 1. O experimento foi conduzido em casa de vegetação (Londrina, PR, Brasil) no delineamento em blocos ao acaso com 3 repetições e parcelas com 15 plantas. Foram avaliadas seis progênies da cultivar IPR 100 e a cultivar Mundo Novo IAC 376-4 foi utilizada como padrão suscetível. Foram inoculados 500 ovos por planta, totalizando 7500 ovos por parcela de 150 cm². Foi avaliado o número de galhas e massas de ovos presentes nas raízes. As seis progênies da cultivar IPR 100 foram mais resistentes ao M.incognita raça 1 do que o padrão suscetível.
The objective of this study was to identify progenies of Coffea arabica cv. IPR 100 with resistance to nematode Meloidogyne incognita race 1. The experiment was performed in greenhouse (Londrina, PR, Brazil) with an experimental design of randomized blocks with 3 replications and 15 plants per plot. Six progenies of cultivar IPR 100 were evaluated, and Mundo Novo IAC 376-4 cultivar was used as susceptible control. Five hundred eggs per plant were inoculated, totalizing 7500 eggs per plot of 150 cm². The number of galls and egg masses in the roots were evaluated. All progenies of cultivar IPR 100 presented more resistance to M.incognita race 1 than the susceptible control.
ABSTRACT
Neste trabalho, objetivou-se identificar em genótipos de café arábica (Coffea arabica L.) fontes de resistência à necrose de frutos em condições de campo. As variáveis resistência à necrose de frutos ("NF"), quantidade média de frutos por nó produtivo ("FN") e índice de luminosidade dentro da copa da planta ("LUM") foram avaliadas em ensaio de campo no IAPAR (Londrina), em dezembro de 2004, em cafeeiros com três anos de idade. Foi avaliada a variável "NF", atribuindo notas de 1 a 5 sendo 1 para plantas com 0 por cento a 5 por cento de frutos necrosados. "FN" foi avaliada seguindo uma escala de notas de 1 a 5, onde 1 representa plantas com 0 a 3 frutos/ nó e nota 5 com mais do que 15 frutos/ nó. A avaliação da variável "LUM" foi visual e seguiu as notas de 1 a 5, onde 1 representa plantas com pouca luminosidade dentro da copa da planta. Dos 19 genótipos avaliados, 2 apresentaram moderada resistência, 7 moderada suscetibilidade, 5 suscetíveis e 5 altamente suscetíveis. As cultivares Obatã IAC 1669-20 e Catucaí Vermelho 4-79 apresentaram o melhor nível de resistência parcial de campo, ou seja, com moderada resistência à necrose de frutos associada ao Colletotrichum spp.
The aim of this research was to identify in Coffea arabica L. coffee genotypes resistance sources to fruit necrosis in field conditions. The variables fruit necrosis ("NF"), fruits per productive nodes average ("FN") and luminosity index inside of the plant canopy ("LUM") were evaluated in field assay at IAPAR (Londrina), in December 2004 on three years old coffee trees. The "NF" variable were evaluated attributing scores from 1 to 5, where score 1 represented plants with 0 to 5 percent of necrosed fruits. "FN" were evaluated following a score scale from 1 to 5, where score 1 represented plants with 0 to 3 fruits/ node and score 5 with more than 15 fruits/ node. The evaluation of the variable "LUM" was visual and followed the scores from 1 to 5, where score 1 represented plants with low luminosity inside the canopy. Out of the 19 evaluated coffee genotypes, 2 presented moderate resistance, 7 moderate susceptibility, 5 susceptibility and 5 high susceptibility. The cultivars Obatã IAC 1669-20 and Catucaí Vermelho 4-79 presented the best level of partial field resistance, or either, with moderate resistance to fruit necrosis associated to Colletotrichum spp.
ABSTRACT
O fungo Colletotrichum spp. vem sendo associado à graves perdas para a cafeicultura brasileira. Objetivou-se neste trabalho verificar a existência de relação entre a variável necrose de frutos associada ao Colletotrichum spp. ("COL") com a quantidade média de frutos por nó produtivo ("FN") e com a produção ("PRD") em genótipos de café arábica. O ensaio de campo foi realizado no IAPAR (Londrina, PR, Brasil) em dezembro de 2004 e em cafeeiros com três anos de idade. A variável "COL" foi avaliada atribuindo-se notas de 1 a 5, onde 1 representam plantas com 0 por cento a 5 por cento de frutos necrosados. "FN" foi avaliada seguindo uma escala de notas de 1 a 5, onde 1 representa plantas com 0 a 3 frutos/ nó e nota 5 com mais do que 15 frutos/ nó. A avaliação visual subjetiva da produção foi estimada em litros de frutos em estádio cereja, por planta. A correlação de Pearson foi estimada para avaliar a existência de associações entre as variáveis. Foram observadas correlações positivas e significativas a 1 por cento entre "COL" e "FN" e entre "COL" e "PRD". A necrose de frutos foi mais intensa em cafeeiros com mais produção e com mais frutos por nó produtivo. Sugere-se que a avaliação da resistência de campo à necrose dos frutos associada à presença de Colletotrichum spp. seja realizada em cafeeiros com alta produção e com alta quantidade de frutos por nó produtivo.
Different fungi species of genus Colletotrichum has been associated with losses to the Brazilian coffee crop. The aim of this research was to evaluate the association between the variable fruit necrosis associated to Colletotrichum spp. ("COL") with the fruits per productive node average ("FN") and between "COL" and the yield ("PRD") in Coffea arabica L. genotypes. The field assay was evaluated at IAPAR (Londrina, PR, Brazil), in December 2004 and on coffee trees with three years old. The "COL" variable was evaluated attributing scores from 1 to 5, where score 1 represents plants with 0 percent to 5 percent of necrosed fruits. "FN" was evaluated following a score scale from 1 to 5, where score 1 represents plants with 0 to 3 fruits/ node and score 5 with more than 15 fruits/ node. The yield per plant was estimated by visual evaluation in liters of cherry fruits per plant. The Pearson's coefficient of correlation was estimated to evaluate the associations between variables. Positive and significant correlations were observed at 1 percent between "COL" x "FN" and between "COL" x "PRD". The fruit necrosis was higher on coffees with higher yield and higher number of fruits per productive node. It is suggested that the field evaluation for resistance to fruit necrosis would be better if accomplished on coffee trees with high yield and high number of fruits per productive node.
ABSTRACT
The aim of this work was to evaluate the resistance to rust in coffee carrying S H3 gene and other S H genes. Twenty one CIFCs coffee trees with several resistance genes S H were evaluated in field conditions. All the evaluated coffees carrying Sh3 gene presented resistance to the rust. It was possible that rust races with the virulence gene v3 in the Paraná State didnt exist. The S H3 gene in combination with genes S H5, S H6, S H7, S H8, S H9 and S H? would be very important to obtain cultivars with more durable resistance to the rust.
O objetivo deste trabalho foi avaliar a resistência à ferrugem em cafeeiros portadores do gene S H3 e outros genes S H em Londrina, Paraná, Brasil. Foram avaliados vinte e um cafeeiros do CIFC com diferentes genes S H de resistência em condição de alta incidência natural em campo. Todos os cafeeiros avaliados portadores do gene S H3 apresentaram resistência à ferrugem. É possível que não existam raças de ferrugem com o gene de virulência v3 no Paraná. Plantas portadoras do gene S H3 em combinação com os genes S H5, S H6, S H7, S H8, S H9 e S H? seria muito importante para obter cultivares com resistência mais durável à ferrugem.
ABSTRACT
The aim of this study was to identify plants of the IAPAR-59 and Tupi IAC 1669-33 coffee cultivars with less defeated resistance genes by the rust races present at IAPAR (Londrina, Paraná State, Brazil) using test-crosses. Eighteen test-crosses derived from hybridizations between 'IAPAR-59' or 'Tupi IAC 1669-33' with susceptible coffee to the rust disease were evaluated. Six hybrids were used as susceptible standards originated from hybridizations between two susceptible coffee plants. Many parental plants of the 'IAPAR-59' and 'Tupi IAC 1669-33' presented more defeated resistance genes against rust races present at IAPAR than others of these cultivars or the genes were in heterozygous, because of segregant susceptible plants observed in some test-crosses. The test-crosses were very efficient to identify plants with less defeated resistance genes to the H. vastatrix. Coffee plants considered resistants would must be made test-crosses to verify which plants presented less and/or more defeated genes in homozygous.
A ferrugem é uma das principais doenças do café. O objetivo deste trabalho foi identificar plantas das cultivares IAPAR-59 e Tupi IAC 1669-33 com menos genes de resistência quebrados às raças de ferrugem presentes no IAPAR (Londrina, Paraná, Brasil) através de cruzamentos testes. Foram avaliados 18 cruzamentos testes derivados dos cruzamentos de 'IAPAR-59' ou 'Tupi IAC 1669-33' com cafeeiros suscetíveis à ferrugem. Seis híbridos foram usados como testemunhas suscetíveis derivados do cruzamento de dois cafeeiros suscetíveis. Muitas plantas da 'IAPAR-59' e 'Tupi IAC 1669-33' apresentam mais genes de resistência quebrados pelas raças de ferrugem presentes no IAPAR do que outras dessas cultivares ou os genes estão em heterozigoze, pois foram observadas muitas plantas segregantes suscetíveis em alguns cruzamentos testes. Os cruzamentos testes são muito eficientes para selecionar plantas com menos genes de resistência à ferrugem quebrados. Em cafeeiros de cultivares considerados resistentes deveriam ser feitos cruzamentos testes para verificar quais plantas apresentam menos genes de resistência quebrados ou mais genes em homozigoze.
ABSTRACT
The aim of this study was to evaluate the resistance to fruit necrosis associated to Colletotrichum spp. in Coffea arabica L.. Twenty-two arabic coffee genotypes were performed in a randomized block design, with three replications and ten plants per plot. They were evaluated for the variables fruit necrosis, luminosity index inside of the plant canopy and fruits per productive nodes of the plants. There was genetic variability for the resistance to fruit necrosis. Different partial resistance levels, varying from highly susceptible (score = 3.89) to moderately resistant (score = 1.77) were observed. The genotypes that presented moderate resistance were the cultivars IPR-100, IPR-103, IPR-105 and IPR-108 and the coffee selection IAPAR-00023.
Diferentes espécies de fungo do gênero têm sido associadas a perdas na cafeicultura brasileira. O objetivo deste trabalho foi avaliar a resistência à necrose de frutos associada ao Colletotrichum spp. em Coffea arabica L.. Vinte e dois genótipos de café foram avaliados no delineamento em blocos ao acaso com três repetições e dez plantas por parcela. As avaliações foram realizadas no IAPAR, Londrina, em janeiro de 2004 para as variáveis necrose de frutos, índice de luminosidade dentro da copa da planta e frutos por nó produtivo. Existe variabilidade genética em cafeeiros arábicos para a resistência à necrose de frutos. Foi observado diferentes níveis de resistência parcial, variando de altamente suscetível (nota = 3,89) a moderadamente resistente (nota = 1,77). Os genótipos que apresentaram moderada resistência foram as cultivares IPR-100, IPR-103, IPR-105 e IPR-108 e a seleção de café IAPAR-00023.
ABSTRACT
No Estado do Paraná, os nematóides mais danosos para o café são Meloidogyne paranaensis e M. incognita raças 1 e 2. A enxertia de cultivares suscetíveis de Coffea arabica sobre C. canephora resistentes tem sido bem sucedida, especialmente com o porta-enxerto Apoatã IAC-2258, porém existe segregação para a resistência. O objetivo deste trabalho foi identificar cafeeiros de C. canephora var. robusta com resistência simultânea aos nematóides M. parnaensis e M. incognita raças 1 e 2. Avaliaram-se 24 genótipos de C. canephora na metodologia de Taylor, no delineamento em blocos ao acaso com três repetições e parcelas de 30 plantas. Como testemunha suscetível utilizou-se a cultivar Mundo Novo IAC 376-4. As variáveis avaliadas foram incidência dos nematóides e volumes radicular. Os níveis de resistência encontrados entre as plantas foram resistente, moderadamente resistente e suscetível. Foram identificados seis genótipos do porta-enxerto C. canephora var. robusta com resistência, provavelmente em homozigoze, para os nematóides M. paranaensis, M. incognita raça 1 e M. incognita raça 2, todos com bom volume radicular. As plantas mães desses seis melhores genótipos serão propagadas vegetativamente e usadas para formar campo de sementes de cultivares porta-enxertos.
The Meloidogyne paranaensis and M. incognita races 1 and 2 are the most pathogenic root knotnematodes of coffee crop in Paraná state, Brazil. The use of susceptible arabica cultivars on resistantrootstock robusta cultivars, especially cultivar Apoatã IAC-2258 of Coffea canephora var. robusta, hasbeen successful, but there are segregations to susceptible ones. The aim of this research was to identify C. canephora var. robusta coffee trees with simultaneous resistance to M. paranaensis, M. incognitaraces 1 and 2. Twenty-four C. canephora genotypes were evaluated using Taylor Ìs evaluation method,conducted in randomized blocks design with three replications and 30 plants per plot. The cultivarMundo Novo IAC 376-4 was used as susceptible standard. The variables evaluated were nematodesincidence and root volume. The resistance levels founded among plants were resistant, moderatelyresistant and susceptible. Six genotypes of C. canephora var. robusta with simultaneous resistance,probably in homozygous, to M. paranaensis, M. incognita race 1 and M. incognita race 2 were found,all with good root volume. The mother plants of these six better treatments will be vegetatively propagatedand used to begin seed production of rootstock cultivars
Subject(s)
Coffee , TylenchoideaABSTRACT
Existe uma grande necessidade de testes que possibilitem uma avaliação rápida e segura da qualidade das sementes. O objetivo deste trabalho foi estimar o coeficiente de correlação existente entre a germinação de sementes de café e a liberação de exsudato marrom. Utilizaram-se placas de Petri e papel-toalha umedecido onde foram colocadas as sementes. Os materiais foram obtidos de lotes de sementes com vários níveis de envelhecimento. Foi utilizado o delineamento em blocos ao acaso com 7 repetições e parcelas constituídas de 10 sementes. Obtiveram-se correlações negativas altas e significativas a 1 entre a germinação e vigor germinativo com a liberação de exsudato marrom. As análises de variância indicaram diferenças significativas na germinação entre sementes de diferentes graus de envelhecimento em relação aos exsudatos marrons. A vantagem desta técnica é avaliar o poder germinativo em poucas horas, sem o uso de mão-de-obra especializada e equipamentos caros.
A quick evaluation of the germination quality of the seeds is very important for coffee growers. The aimof this research was to estimate the correlation coefficient between the germination and the liberation ofbrown exudates of coffee seeds with different times after preparation. Petri dishes and humid filter wereused to place the seeds. The seeds were obtained from lots of seeds with several aging degrees. Theexperimental design used was in randomized blocks with seven replications and plots constituted by 10seeds. High negative correlations (P=0.01) were obtained between the germination and germinativevigour with the liberation of brown exudates at different times. The variance analyses indicated significantdifferences to germination among seeds of different aging degrees at different evaluation times. Theadvantage of this technique is to evaluate the germinative quality in six or twelve hours, without the useof specialized labour and expensive equipments
Subject(s)
Coffee , GerminationABSTRACT
A variabilidade genética de 40 acessos de cafeeiros de fenótipo arabica foi obtida usando a técnica de RAPD associada a uma digestão prévia do DNA genômico com endonucleases. A variabilidade genética e a relação entre os accessos foram inicialmente avaliadas pela amplificação de 195 primers. Para incrementar a eficiência na detecção de polimorfismo, o DNA genômico de cada acessos foi submetido a digestão com endonucleases antes da PCR. Um total de 24 primers combinados com restrição do DNA gerou 318 bandas, das quais 266 (83,65%) foram polimórficas. A associação entre os 40 acessos foi estimada pelo método de clusters UPGMA, sendo os acessos agrupados de acordo com seu pedigree e aspectos agronômicos. Os resultados mostraram que o uso de enzimas de restrição antes da reação de amplificação pode ser considerada uma ferramenta eficiente para incrementar o número de bandas informativas, possibilitando a diferenciação entre os 40 acessos de C. arabica.
ABSTRACT
A variabilidade genética para resistência à geada foi avaliada em campo e em câmara fria entre acessos de Coffea. Os resultados mostraram que C. liberica var. dewevrei e C. racemosa e os híbridos derivados delas foram mais resistentes à geada. Existe grande variabilidade genética para resistência à geada entre estes materiais genéticos estudados (b2 = 0,98). A correlação obtida entre as médias de dano foliar no campo e na câmara fria foi de 0,933**. Esta metodologia é eficiente e prática, com potencial de utilização em um programa de melhoramento para resistência à geada.
ABSTRACT
Knowledge of the genetic variability among genotypes is important for the transfer of useful genes and to maximize the use of available germplasm resources. This study was carried out to assess the genetic variability of 14 elite Coffea arabica cultivars using random amplified polymorphic DNA (RAPD) associated with a prior digestion of genomic DNA with restriction endonucleases. The accessions were obtained from the Coffea collection maintained at the Instituto Agronomico do Parana (IAPAR), located in Londrina, Parana, Brazil. Twenty-four informative RAPD primers, used in association with restriction enzymes, yielded 330 reproducible and scorable DNA bands, of which 224 (68 per cent) were polymorphic. The amplified products were used to estimate the genetic variability using Dice's similarity coefficient. The data matrix was converted to a dendrogram and a three-dimensional plot using principal coordinate analysis. The accessions studied were separated into clusters in a manner that was consistent with the known pedigree. The associations obtained in the dendrogram and in the principal coordinate analysis plot suggest the probable origin of the Kattimor cultivar. The RAPD technique associated with restriction digestion was proved to be a useful tool for genetic characterization of C. arabica genotypes making an important contribution to the application of molecular markers to coffee breeding
Subject(s)
Genetic Variation , Polymorphism, Genetic , Random Amplified Polymorphic DNA Technique , DNA Restriction EnzymesABSTRACT
Inter-simple sequence repeat (ISSR) markers were used to evaluate genetic divergence among eight Coffea species and to identify the parentage of six interspecific hybrids. A total of 14 primers which contained different simple sequence repeats (SSR) were used as single primers or combined in pairs and tested for PCR amplifications. Two hundred and thirty highly reproducible fragments were amplified, which were then used to estimate the genetic similarity and to cluster the Coffea species and hybrids. High levels of interspecific genetic variation were revealed. The dinucleotide motif (GA)9T combined with other di- tri- and tetra-nucleotides produced a greater number of DNA fragments, mostly polymorphics, suggesting a high frequency of the poly GA microsatellite motifs in the Coffea genomes. The genetic similarity ranged from 0.25 between C. racemosa and C. liberica var. dewevrei to 0.86 between C. arabica var. arabica and Hybrid N. 2. The C. arabica species shared most of its markers with five of the six hybrids suggesting that it is the most likely candidate as one of the progenitors of those hybrids. These results revealed that ISSR markers could be efficiently used for genetic differentiation of the Coffea species and to identify the parentage of Coffea interspecific hybrids
Subject(s)
Coffee/genetics , Genetic Markers , Random Amplified Polymorphic DNA TechniqueABSTRACT
The RAPD technique associated with restriction digestion of genomic DNA was used to assess the genetic variability within and among nine populations of Coffea arabica, including six progenies belonging to the Sarchimor germplasm, the progeny PR 77054-40-10 (Catuaí Vermelho IAC 81 x Icatu), and two commercial cultivars (IAPAR 59 and Catuaí Vermelho IAC-81). These populations were evaluated using analysis of molecular variance (AMOVA), genetic similarity among progenies, and percentage of polymorphic loci. A total of 99 RAPD markers were evaluated of which 67 (67.67 percent) were polymorphic. AMOVA showed that 38.5 percent and 61.5 percent of the genetic variation was distributed among and within populations, respectively. The fixation index (F ST) of the genotypes was 0.385. The mean genetic variability estimated within populations ranged from 15.58 (IAPAR 59) to 8.27 (Catuaí Vermelho IAC 81). A distinct level of genetic variability was revealed for each of the coffee progenies and varieties studied. The methodology used in this investigation was useful to determine the genetic variability within and among C. arabica L. populations providing significant information for coffee breeding