Resistance to bacterial blight in arabica coffee cultivars

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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) 9 T 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.

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RESUMOO objetivo desta investigação foi estudar progênies de Coffea arabica quanto a resistência à ferrugem alaranjada, causada por Hemileia vastatrix, e à mancha aureolada, causada por Pseudomonas syringae pv. garcae. O experimento foi instalado no Centro de Produção e Experimentação de Londrina, do Instituto Agronômico do Paraná. Utilizou-se delineamento em blocos ao acaso, com três repetições, 13 tratamentos (11 progênies e as testemunhas 'IAPAR 59' e 'Catuaí Vermelho IAC 81'). Os resultados sugerem investigar a possibilidade da ocorrência de novo(s) patotipo(s) de P. syringae pv. garcae no Paraná. Observou-se na cultivar 'IAPAR 59' resistência suficiente para reduzir danos provocados por P. syringae pv. garcae, causador da mancha aureolada, em regiões de alta ocorrência do patógeno no Paraná. Na progênie "Catuaí" x "Icatú" PRFB 2-27-1/F5 (IAPAR 96095) verificou-se resistência simultânea à ferrugem alaranjada e à mancha aureolada e deverá ser testada em ensaios regionais.Palavras-chave: melhoramento de café, resistência à doenças, cultivar, cafeicultura. ABSTRACT SELECTION OF PROGENIES OF COFFEA ARABICA WITH SIMULTANEOUS RESISTANCE TO BACTERIAL BLIGHT AND LEAF RUSTThis research aimed at to study C. arabica progenies as to resistances to bacterial blight "mancha aureolada", caused by Pseudomonas syringae pv. garcae, and coffee leaf rust, caused by Hemileia vastatrix. The experiment was carried out in the Centro de Produção e Experimentação de Londrina, Instituto Agronômico do Paraná. It was set in a randomized complete block design with 13 treatments (11 progenies and the controls 'IAPAR 59' and 'Catuaí Vermelho IAC 81') and three replications. The results suggest the ocurrence of new(s) pathotype(s) of P. syringae pv. garcae in Paraná State. The IAPAR 59 cultivar is an option to minimize the damage caused by P. syringae pv. garcae in areas of high incidence of this pathogen. The progeny PRFB 2-27-1/F5 (IAPAR 96095) from "Catuaí" x "Icatú" cross presented simultaneous resistance to leaf rust and to bacterial blight ("mancha aureolada"). It will be tested in future regional trials.

RESUMO-atualmente, encontram-se quatorze cultivares de maracujazeiro-amarelo no Registro nacional de cultivares do Ministério da agricultura. É de grande importância o aprimoramento de trabalhos de melhoramento genético nessa cultura, para favorecer a disponibilização de novas cultivares adaptadas às regiões produtoras. assim, o objetivo deste trabalho foi avaliar a produção e as características qualitativas dos frutos de treze híbridos de maracujazeiro-amarelo cultivados no norte do Paraná. as avaliações foram realizadas durante dois ciclos de produção da cultura, de abril a julho de 2009 e de janeiro a julho de 2010, com coletas semanais dos frutos maduros. a produção foi determinada por meio da pesagem dos frutos colhidos e do número de frutos por planta. Para as características qualitativas, foram avaliados: massa, comprimento, diâmetro, relação entre comprimento e diâmetro dos frutos, espessura da casca, rendimento de polpa, teor de sólidos solúveis totais (SSt), acidez total titulável (att) e relação SSt/att. os híbridos '66' e '65' apresentaram, respectivamente, maior produção e maior número de frutos no acumulado das duas safras. os frutos do híbrido '72' destacaram-se no atendimento das características desejáveis de qualidade para o consumo in natura, enquanto o híbrido '69' apresentou caracteristicas importantes para a indústria de suco. Termos para indexação: Maracujá, Passiflora edulis Sims, características físico-químicas. YIELD AND QUALITY OF FRUITS OF HYBRIDS OF YELLOW PASSION FRUIT IN NORTHERN PARANÁABSTRACT -nowadays there are fourteen cultivars of yellow passion fruit on the national Register of cultivars of the Brazilian Ministry of agriculture. the improvement of plant breeding in this crop is of great importance to provide new cultivars adapted to the producing regions. thus, the aim of this study was to evaluate the production and fruit quality of thirteen hybrids of yellow passion fruit plants grown in the northern Paraná. the evaluations were performed during two cycles of crop production from april to July 2009 and from January to July 2010 with weekly harvests of ripe fruits. the production was determined by weighing the total output and counting the number of fruits per plant. the evaluated quality characteristics of the fruits were: weight, length, diameter, diameter/length ratio, thickness, pulp yield, total soluble solids (tSS), total titratable acidity (tta) and tSS/tta ratio. hybrids '66' and '65' respectively showed the highest yield and greatest number of fruits in the accumulated of the two crops. the fruits of the hybrid '72' stood out on desirable quality characteristics for fresh consumption, while the hybrid '69' showed important features for the juice industry.

Porta-enxertos de café robusta resistentes aos nematóides Meloidogyne paranaensis e M. incognita raças 1 e 2Recebido para publicação 15/06/05 Aprovado em 27/11/05 Porta-enxertos de café robusta resistentes aos nematóidesMeloidogyne paranaensis e M. incognita raças 1 e 2 ResumoNo 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. paranaensis e M. incognita raças 1 e 2. Avaliaramse 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 volume 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. Palavras-chave: Coffea canephora, cultura do café, Kouillou, melhoramento, nematóide das galhas AbstractThe Meloidogyne paranaensis and M. incognita races 1 and 2 are the most pathogenic root knot nematodes of coffee crop in Paraná state, Brazil. The use of susceptible arabica cultivars on resistant rootstock robusta cultivars, especially cultivar Apoatã IAC-2258 of Coffea canephora var. robusta, has been 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. incognita races 1 and 2. Twenty-four C. canephora genotypes were evaluated using Taylor´s evaluation method, conducted in randomized blocks design with three replications and 30 plants per plot. The cultivar Mundo Novo IAC 376-4 was used as susceptible standard. The variables evaluated were nematodes incidence and root volume. The resistance levels founded among plants were resistant, moderately resistant 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 propagated and used to begin seed production of rootstock cultivars.

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 Agronômico do Paraná (IAPAR), located in Londrina, Paraná, Brazil. Twenty-four informative RAPD primers, used in association with restriction enzymes, yielded 330 reproducible and scorable DNA bands, of which 224 (68%) 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.