Biochemical and genetic implications of the slow ripening phenotype in peach fruit

The peach [Prunus persica L. (Batsch)] slow ripening (SR) trait is a mutation preventing the normal fruit ripening process. It is determined by a single Mendelian gene (Sr/sr) located on linkage group 4, where only homozygous individuals for a recessive allele (sr) show the SR phenotype and are generally discarded from breeding programs. Ripening-related traits such as fruit weight, firmness loss, ethylene production, ACO activity, sugars and organic acids composition, malondialdehyde, antioxidant capacity and total phenolic content were evaluated in a segregating population for the SR trait during two consecutive harvest seasons and at different maturity stages. Although there is no commercial value for the slow ripening (srsr) individuals, our results demonstrate that a heterozygous combination involving sr and another allele at this locus (Sr2) showed interesting traits including a longer harvest window and improved postharvest behaviour if harvested at the appropriate maturity (IAD ≥ 2). All these traits seem to be linked to a delayed ripening behaviour mediated, in turn, by a lower ethylene production capacity and an altered sugar (mainly sucrose) and organic acid accumulation/utilisation on-tree. The selection of this allelic combination could be an easy and efficient strategy to obtain new peach cultivars with potentially improved shelf life.info:eu-repo/semantics/acceptedVersio

Phenotypic diversity and relationships of fruit quality traits in peach and nectarine [Prunus persica (L.) Batsch] breeding progenies

The definitive version is available at: http://www.springerlink.com/content/102881/Agronomic and fruit quality traits were evaluated and compared for three consecutive years on 1,111 seedlings coming from 15 peach and nectarine breeding crosses, grown under a Mediterranean climate. Significant differences among and within the different progenies were found for most of the traits analyzed. The breeding population segregated for several Mendelian characters such as peach or nectarine fruit, round or flat fruit, yellow or white flesh and freestone or clingstone. In addition, aborting fruit and flat fruit trees were found in our progeny, and our data seem to support multi-allelic control of both flat shape and aborting fruit. The variation within the progenies of some traits such as blooming and harvesting date, yield, fruit weight and SSC was continuous, suggesting a polygenic inheritance. Relationships between qualitative pomological traits and these agronomic and fruit quality parameters were also found. Valuable correlations among agronomic and fruit quality parameters were found, although coefficients of variation depending on the progeny should be considered. In addition, principal component analysis (PCA) revealed several relationships among quality traits in the evaluated progenies. Based on this evaluation, 26 outstanding genotypes were pre-selected from the initial breeding population for further studies.This study was supported by the Spanish MICINN (Ministry of Science and Innovation) grants AGL-2005-05533 and AGL-2008-00283, and the Regional Government of Aragón (A44). C.M. Cantín was supported by a FPU fellowship from Spanish MICINN.Peer reviewe

APLICACIÓN DE ACEITES ESENCIALES EN MANZANA (MALUS DOMESTICA) COMO AGENTES DE BIOCONTROL POSTCOSECHA

La manzana (Malus x domestica) es un fruto de pepita de gran importancia en cuanto a superficie productiva en España, el cual también tiene relevancia en la cesta de la compra de la población española. Aunque su valor nutricional es claro, su consumo ha disminuido notablemente durante los últimos 30 años entre la población española a pesar de la gran producción nacional. Factores que pueden afectar al precio y la calidad del fruto provienen tanto de las etapas precosecha como postcosecha. Entre los factores bióticos alterantes de la calidad, los hongos son de gran importancia, ya que se manifiestan fundamentalmente durante el transporte y almacenamiento. Para evitar pérdidas causadas por daños de podredumbres fúngicas, comúnmente se hace uso de fungicidas de síntesis química. Sin embargo, a causa de sus efectos nocivos para el medio ambiente y la salud humana, estos productos químicos están siendo sustituidos gradualmente. Una alternativa para ellos pueden ser los aceites esenciales (AEs) de plantas aromáticas.El objetivo de este Trabajo Fin de Máster (TFM) fue la búsqueda de AEs de plantas aromáticas provenientes de Aragón como alternativa a los fungicidas de origen químico. Para alcanzar este objetivo se desarrolló una parte de ensayos in vitro y otra in vivo, en las cuales se trabajó con AEs de Mentha rotundifolia, Origanum virens, Salvia officinalis y Valeriana officinalis, para los que se evaluó su capacidad antifúngica frente a los hongos Monilinia fructicola, Botrytis cinerea, Alternaria alternata, Rhizopus stolonifer y Penicillium expansum.Los métodos utilizados durante la parte in vitro consistieron en la difusión de AEs en disco, la dilución de AEs en Agar Dextrosa Patata (PDA), dilución de AEs Caldo de Patata Dextrosa (PBD), medición de la actividad volátil y generación de esporas en Agar Dicloran Rosa de Bengala Cloranfenicol (DRBD). La parte in vivo consistió en la evaluación de las infecciones provocadas por los cinco hongos en manzana protegidas con los AEs testados.De la parte in vitro de este TFM se concluyó que un 10% de concentración de los AEs es excesivo, aunque S. officinalis presentó aun así un efecto nulo. Se concluyó también que las concentraciones fungicidas ideales del resto de AEs se encontraba entre 0,25 y 1%. En la parte in vivo se aplicaron los AEs a una concentración de 0,5% y 5%. Los resultados mostraron que M. fructicola presentaba un crecimiento anómalamente disminuido. Por otro lado, el AE de M. rotundifolia y O. virens al 5% demostraron ser una posible alternativa a los fungicidas químicos contra P. expansum y contra B. cinerea respectivamente. Mientras A. alternata mostró ser susceptible a M. rotundifolia, pero no de forma concluyente. R. stolonifer demostró ser muy resistente a los tratamientos.<br /

Creación de un panel de catadores entrenados para la caracterización sensorial de manzana

Hoy en día, la selección de nuevos alimentos agroalimentarios se basa cada vez más en la calidad del producto; y los eslabones de la cadena agroalimentaria se deben centrar en el consumidor como factor primordial. Para ello, el análisis sensorial es una herramienta esencial para la evaluación de la calidad del fruto que permite la obtención de información compleja a partir de jueces entrenados. Por este motivo, este trabajo se basa en la creación de un panel entrenado para la caracterización sensorial de manzana, pasando por cada una de las fases que conlleva este entrenamiento: la fase de reclutamiento, donde se buscan participantes voluntarios para la formación del panel; la fase de selección, en la que se decidirá qué candidatos van a pasar a formar parte del panel; la fase de entrenamiento, en la que los panelistas son entrenados en los diferentes aspectos del análisis sensorial general y concretamente en el análisis sensorial de manzana; y por último la sincronización del panel, con el fin de conseguir resultados consensuados y coherentes como panel de catadores entrenado de manzana.<br /

USO DE ACEITES ESENCIALES PARA LA CONSERVACIÓN POSTCOSECHA DE FRUTA DE PEPITA

La manzana es una de las frutas de mayor producción y consumo en España. Tras su recolección, se producen grandes pérdidas económicas debido a la acción de diferentes hongos como Monilinia fructicola, Botrytis cinerea, Alternaria alternata, Rhizopus stolonifer y Penicilliumexpansum. El empleo de técnicas alternativas a la aplicación de fungicidas tradicionales es necesario en la actualidad, evitando efectos negativos sobre el medio ambiente y el rechazo por parte del consumidor.Para ello, en este trabajo se propone la utilización de aceites esenciales (AEs) de las especies Origanum virens, Salvia officinalis, Valeriana officinalis y Mentha rotundifolia, junto con sus hidrolatos, un subproducto obtenido de las destilaciones de los AEs que está constituidoprincipalmente por compuestos hidrosolubles, y algunos de los compuestos activos presentes en estos AEs (Linalool, Timol, β-pineno, Acetato de bornilo, Canfeno y Carvacrol).Los métodos empleados para su aplicación fueron la difusión de AEs en disco, la dilución de AEs e hidrolatos en Agar Dextrosa Patata (PDA), dilución de AEs e hidrolatos en Caldo de Patata Dextrosa (PBD), actividad volátil, generación de esporas en Agar Dicloran Rosa de BengalaCloranfenicol (DRBD), y difusión de compuestos activos en PDA.El método de difusión de AEs en PDA, junto con el de difusión de los compuestos activos en PDA, fueron los que proporcionaron los mejores niveles de inhibición del crecimiento. En el primer caso, todos los AEs tuvieron gran eficacia contra los microorganismos, con excepción de S.officinalis que solo género inhibición frente a M. fructicola. En el caso de difusión de compuestos activos en PDA, los compuestos que presentaron una mayor capacidad antifúngica de forma general fueron linalool, timol y carvacrol, dando lugar a inhibiciones totales en el crecimiento detodos los hongos, teniendo en cuenta las diferentes concentraciones aplicadas.<br /

Impact Of Chill And Heat Exposures Under Diverse Climatic Conditions On Peach And Nectarine Flowering Phenology

The present study aims to generalize cultivar-specific tree phenology responses to winter and spring temperatures and assess the effectiveness of the Tabuenca test and various chill and heat accumulation models in predicting bloom dates for a wide range of climatic conditions and years. To this end, we estimated the dates of rest completion and blooming and correlated them with observed bloom dates for 14 peach and nectarine cultivars that were evaluated in 11 locations across Europe (Greece, France, Italy, Romania and Spain), within the EUFRIN cultivar testing trial network. Chill accumulation varied considerably among the studied sites, ranging from 45 Chill Portions (CP) in Murcia-Torre Pacheco (Spain) to 97–98 CP in Cuneo (Italy) and Bucharest (Romania). Rest completion occurred latest or was not achieved at all for some cultivars in the southern sites in Murcia. Dormancy release happened earliest in Bucharest and Cuneo, sites where heat accumulation had a strong influence on the regulation of bloom time. Blooming occurred earliest in the moderately cold regions of Lleida (Spain) and Bellegarde (France), and 7–11 days later in the warmer locations of Rome (Italy) and Naoussa (Greece), suggesting that bloom timing is strongly influenced by delayed rest completion in these locations. The Dynamic Model resulted in both more homogeneous chill accumulation across years and better predictions of bloom dates, compared with the Utah, Positive Utah and Chilling Hours models. Prediction of bloom dates was less successful for low-chill cultivars than for medium- and high-chill cultivars. Further climatic and experimental data are needed to make estimates of the climatic needs of peach cultivars more robust and to generate reliable advice for enhancing the resilience of peach production under varying and changing climatic conditions.info:eu-repo/semantics/publishedVersio

Estudio agronómico y de la calidad del fruto del melocotonero [P. persica (L.) Batsch] en diferentes poblaciones de mejora para la selección de nuevos cultivares

230 Pag.[ES] El objetivo general de este estudio fue la selección de nuevos genotipos de melocotón y nectarina para el sector frutícola español, adaptados a las condiciones mediterráneas del Valle Medio del Ebro. Los objetivos específicos de mejora de este programa incluyen la extensión del calendario de cosecha, la obtención de nuevos tipos de fruto y la mejora de la calidad de los mismos (forma, color de la piel y la pulpa, firmeza, sabor, contenido en azúcares y compuestos bioactivos, etc.).[EN]The final objective of this study was the selection of outstanding peach and nectarine genotypes for the Spanish industry, with good adaptation to Mediterranean conditions when grown in the Ebro Valley. The specific breeding goals of this program were the extension of the harvest period, the release of new fruit types and the improvement of the fruit quality (shape, skin and flesh color, firmness, flavor, sugars and bioactive compounds content, etc.).Peer reviewe

Application of abscisic acid (ABA) at veraison advanced red color development and maintained postharvest quality of ‘Crimson Seedless’ grapes

The final version is available at: http://www.sciencedirect.com/science/journal/09255214‘Crimson Seedless’ is a popular table grape cultivar, but in warm-climates, its fruits often fail to develop adequate red color, even after they have been treated with ethephon. Application of abscisic acid (ABA) may improve color more effectively than ethephon, but its potential effects on postharvest quality must be considered before recommending its use on table grapes. Therefore, we compared the postharvest quality attributes of grapes treated preharvest with 250 μL L−1 ethephon, the current industry standard, to that of grapes treated with 150 or 300 μL L−1 ABA, or nontreated. Treatment with either ethephon or 150 μL L−1 ABA allowed grapes to be harvested 10 d before nontreated fruit, and fruits treated with 300 μL L−1 ABA attained marketable quality 30 d before nontreated fruit. Early harvest was possible because the treatments induced more rapid coloring of the grapes, and though total yield was not affected by any plant growth regulator (PGR), all PGRs doubled packable yields by improving the color of the grapes. ABA-treated grapes were characterized by superior appearance both in berries and clusters’ rachises compared to ethephon-treated and control grapes. Other quality attributes such as firmness, berry weight, decay incidence, and shatter remained unaffected among treatments. Therefore, ABA is an effective alternative to ethephon for enhancing the color and maintaining postharvest quality of ‘Crimson Seedless’ grapes.The authors acknowledge financial support from the California Table Grape Commission, the California Competitive Grants Program for Research in Viticulture and Enology, and from Valent BioSciences. Ms. Celia M. Cantín was supported by a FPU fellowship from Spanish MEC (Ministerio de Educación y Ciencia).Peer reviewe

Identification of a new allele of the Dw gene causing brachytic dwarfing in peach

Abstract Objective Peach brachytic dwarfism determined by Dwarf gene (Dw) is an undesired trait segregating in some peach breeding programs. Recently, a single nucleotide polymorphism (SNP) mutation in the gibberellin insensitive dwarf 1 (GID1) peach gene causing brachytic dwarfism was described. In this research we wanted to validate this marker in an F2 population of the ‘Nectavantop’ peach cultivar (Nv) to include it as a marker assisted selection tool for peach breeding programs. Results The observed segregation of the trait was in agreement with that of a recessive gene, the individuals homozygous for the recessive allele (dwdw) presenting the dwarf genotype. Dw was mapped to the distal part of linkage group 6 as previously described. The SNP marker based on the causal mutation previously described did not segregate in Nv F2 population. The sequence of the GID1c gene in Nv revealed a second SNP in its coding sequence which cosegregated with the dwarf phenotype. This SNP was predicted by the SNAP2 software to cause a major functional change and was validated in the dwarf peach cultivar ‘Small sunning’. These results suggest the existence of at least two independent mutations of the Dw gene causing the peach brachytic dwarf phenotype

Fruit quality attributes of new peach and nectarine varieties under selection in the Ebro valley conditions (Spain)

7 Pags.- 1 Tabl.- 3 Figs. The definitive version is available at: http://www.actahort.orgA breeding program searching for new peach and nectarine varieties adapted to the Ebro Valley growing conditions is being developed at the Aula Dei Experimental Station (CSIC). This program evaluates 15 populations obtained by controlled crosses. Different agronomic parameters such as blooming date, yield, and ripening date were determined in these populations. Quality traits such as fruit type, weight, flesh firmness, soluble solids content (SSC), total phenolics content, antioxidant activity, and other chemical attributes were determined and evaluated. In addition, market life was tested based on chilling injury (CI) susceptibility. Several parameters studied such as yield, SSC, sugars composition, total phenolics, and CI sensibility showed a great variability within the different populations.Supported by the Spanish Ministry of Education and Science (AGL2002-04219 and AGL2005-05533, co-financed by FEDER), and DGA (A28 and A44) grants. C.M. Cantín was supported by a FPU fellowship from Spanish MEC (co-financed by FSE).Peer Reviewe