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The nature and structure of genetic diversity in the Spanish apple germplasm preserved at the national level was widely unknown, since studies performed to date on this topic have been exclusively carried out at the regional scale. Here, 1453 accessions from Spanish collections of Malus × domestica were evaluated with a common set of 13 SSR (Simple Sequence Repeats) markers in order to estimate genetic diversity, to identify the underlying genetic structure and to unravel the relationships among them and among a wide set of international cultivars for reference. In total, 737 unique genotypes were identified, 581 diploids and 156 triploids. Using a model-based Bayesian clustering procedure, two reconstructed populations were obtained for diploid genotypes; one retaining only Spanish cultivars (42% of genotypes), and a second containing all foreign cultivars the latter exhibiting evidence supporting the existence of a secondary sub-structure. Similarly, analysis performed on the 156 triploid genotypes also revealed two reconstructed populations; one exclusively associated with local Spanish genotypes (44%). The Jaccard coefficient allowed clustering by UPGMA (Unweighted Pair Group Method) diploid and triploid genotypes, and remarkable differences in allelic composition among the different partitioning levels were found. AMOVA analyses showed moderate but significant differentiation among the main groups (0.08 ≤ FST ≤ 0.12). Our results highlight an important fraction of the Spanish apple germplasm that constitutes a differentiated genepool with respect to the international and commercial apple cultivars. Moreover, the extent of the Spanish genetic diversity was spatially distributed along the northern Iberian Peninsula, suggesting an extensive migration of genotypes along the country. This study is the first valuable action for genetic conservation of apple at the national scale, and constitutes a decisive step towards the definition of a Spanish core collection that will be useful for further studies in dissecting the genetic control of important horticultural traits through genome-wide association analysis in apple.

Background and Aims Vineyards, one of the most widespread agricultural systems, have significant but scarcely evaluated carbon sequestration potential. Allometry is a cost-effective approach to estimate plant biomass, but few studies – focused mainly on permanent structure carbon fixation – have dealt with it in grapevine. This study develops allometric models that accurately estimate grapevine standing biomass (total vine biomass at harvest), using extensive field-collected data sets. Methods and Results Data were obtained in vineyards located in Spanish regions representative of the variability found in warm semi-arid Mediterranean regions. We developed and validated functions to estimate vine biomass for all vine organs. The models obtained estimated accurately the biomass fixed by each organ separately and even more accurately at the whole plant scale. To illustrate the potential of the models, they satisfactorily assessed the influence of seasonal vine water status on vine biomass production and partitioning using an independent data set. Conclusions and Significance of the Study The models constitute a powerful tool to determine in a non-destructive and cost-effective manner standing biomass from simple vine measurements, which makes them suitable for quantifying carbon stocks and allocation patterns, and for evaluating the influence of climate or cultural practices at large scale to estimate better – at a regional or international level – the contribution of grapevine culture to CO2 balances.

Carbon isotope ratio (δ13C) has been increasingly used in the study of grapevine water relations, and the main challenge for physiologists and agronomists is now to harness the information δ13C provides. One of the fields where δ13C can be more useful is modelling, as in this discipline, measuring plant water status with a sufficient frequency is not usually feasible. The aim of this work is to evaluate the interest of including δ13C data on modelling of three relevant agronomical variables such as yield, berry weight and sugar concentration (TSS) at three scales: within-vineyard, at domain and at regional scale. The models calculated showed that δ13C is a useful tool for modelling variations in yield and berry weight at the three scales, but this ability was not observed for modelling sugar concentration. The fact δ13C had a relevant role in berry weight modelling at the three scales needs to be highlighted, and underlines the great relevance water availability has in Mediterranean viticulture.

Monitoring grapevine water status by means of measuring the reflectivity at the trunk in the terahertz band is presented. A grapevine is located inside a growth chamber to simulate diverse outdoor conditions and correlate them with variations produced in the reflected signal of the trunk. Modifications of light conditions, temperature, and irrigation of the grapevine are recorded either in time domain broadband measurements as well as in the magnitude and phase of narrowband measurements in the frequency domain. The results are compared with traditional techniques using a dendrometer and a humidity probe with excellent agreement.

A quick and accurate sampling method for determining yield in peach orchards could lead to better crop management decisions, more accurate insurance claim adjustment, and reduced expenses for the insurance industry. Given that sample size depends exclusively on the variability of the trees on the orchard, it is necessary to have a quick and objective way of assessing this variability. The aim of this study was to use remote sensing to detect the spatial variability within peach orchards and classify trees into homogeneous zones that constitute sampling strata to decrease sample size. Five mature peach orchards with different degrees of spatial variability were used. A regular grid of trees was established on each orchard, their trunk cross-sectional area (TCSA) was measured, and yield was measured as number of fruits/tree on the central tree of each one of them. Red Vegetation Index (RVI) was calculated from aerial images with 0.25 m&middot, pixel&minus, 1 resolution, and used, either alone or in combination with TCSA, to delineate sampling strata using cluster fuzzy k-means. Completely randomized (CRS) and stratified samplings were compared through 10,000 iterations, and the Minimum Sample Size required to obtain estimates of actual production for three quality levels of sampling was calculated in each case. The images allowed accurate determination of the number of trees, allowing a proper application of completely randomized sampling designs. Tree size and the canopy density estimated by means of multispectral indices are complementary parameters suitable for orchard stratification, decreasing the sample size required to determine fruit count up to 20&ndash, 35% compared to completely randomized samples.

Thermal imaging can become a readily usable tool for crop agricultural water management, since it allows a quick determination of canopy surface temperature that, as linked to transpiration, can give an idea of crop water status. In the last years, the resolution of thermal imaging systems has increased and its weight decreased, fostering their implementation on Unmanned Aerial Vehicles (UAV) for civil and agricultural engineering purposes. This approach would overcome most of the limitations of on site thermal imaging, allowing mapping plant water status at either field or farm scale, taking thus into account the naturally existing or artificially induced variability at those scales. The aim of this work was to evaluate to which extent high-resolution thermal imaging allows evaluating the instantaneous and seasonal variability of water status within a vineyard. The novelty and significance of our approach is that the specifically designed and build unmanned aerial vehicle (UAV) provided very high-resolution imaging (pixel

Aim: An advance in grapevine phenological stages (including ripening) is occurring worldwide due to global warming and, in the hottest seasons, already results in a lack of synchrony between sugar and phenolic ripeness, leading to unbalanced wines. In order to cope with this fact, a general effort is being made by researchers and growers aiming at delaying ripening through cultural practices, particularly under warm growing conditions, where these effects are more deleterious. The aim of this work is to evaluate to which extent severe trimming and enhanced competition of laterals can delay ripening in Tempranillo vineyards under semiarid conditions.Methods and results: The experiment took place during two consecutive seasons in Traibuenas (Navarra, Spain) in a cv. ‘Tempranillo’ vineyard trained to a vertical shoot positioned (VSP) spur-pruned bilateral cordon. Severe mechanical pruning was performed ca. 3 weeks after fruit-set in order to reduce leaf-to-fruit ratio, and in the trimmed plants, three irrigation doses were applied until harvest aiming at enhancing lateral growth, hypothesized to compete with ripening. All measurements were performed in six 10-vine replicates per treatment. Trimming significantly reduced leaf area and yield, resulting in higher water availability in trimmed plants. The whole ripening process was delayed by trimming: mid-veraison was delayed by about 5 days, and the delay in sugar accumulation and acid degradation was longer, differences being more marked in malic than in tartaric acid concentration. The use of increased irrigation levels compensated the losses in yield caused by trimming, enhanced laterals’ growth and implied an additional delay in ripening.Conclusion: trimming and increased irrigation had an additive effect in terms of delaying ripening, and they can be used jointly when that delay is needed.Significance and impact of the study: this study proves the potentiality of the joint use of trimming and increased irrigation to delay ripening, although it is necessary to analyze the implications the obtained delay has on other quality aspects. The lower anthocyanin and phenolic values observed in trimmed vines were not solely due to delayed ripening, as lower values were observed even when data were compared for a given total soluble solid content.

Source to sink size ratio, i.e.: the relative abundance of photosynthetically active organs (leaves) with regards to photosynthate demanding organs (mainly bunches), is widely known to be one of the main drivers of grape oenological quality. However, due to the difficulty of remote sink size estimation, Precision Viticulture (PV) has been mainly based on within-field zone delineation using vegetation indices. This approach has given only moderately satisfactory results for discriminating zones with differential quality. The aim of this work was to investigate an approach to delineate within-vineyard quality zones that includes an estimator of sink size in the data-set. The study was carried out during two consecutive seasons on a 4.2 ha gobelet-trained cv. 'Tempranillo' vineyard. Zone delineation was performed using Normalized Difference Vegetation Index (NDVI), soil apparent electrical conductivity (ECa) and bunch number (BN) data. These variables were considered separately, in pairs, or the three altogether, using fuzzy k-means cluster analysis for combinations. The zones delineated based on single variables did not allow a sufficient discrimination for grape composition at harvest, NDVI being the only variable that by itself resulted in zones that to some extent differed in grape composition. On the contrary, when two variables were combined, discrimination in terms of grape composition improved remarkably, provided the sink size estimation variable (BN) was included in the combination. Lastly, the combination of the three variables yielded the best discriminating zoning, improving slightly on those provided by NDVI + BN and ECa + BN combinations. Thus, the relevance of including a variable related to sink size (in this case the number of bunches per plant) has been confirmed, which makes its consideration highly advisable for any PV work aiming at zone delineation for grape quality purposes. This work was funded by the Dpt. Innovación, Industria & Empleo of the Government of Navarra (MODELVID, Ref: IIM11879.RI.1), by the Centro para el Desarrollo Tecnológico Industrial CDTI (Ref: IDI-20100729, co-funded by the European Union ERDF as part of the Operational Programme I+D+i Technology Fund 2007-2013) and by Fundación Fuentes Dutor. The Spanish Ministry of Education funded I.U. stage in SupAgro, Montpellier (EDU/2719/2011).

[Background and aims] Viral diseases in grapevines result in reduced vineyard performance, but it remains unclear to which extent some of their effects are direct or indirect, or if both kinds of effects co-occur. The aim of this work is to evaluate the effect of three virus diseases (GFLV, GLRaV and GFkV) on cv. Tempranillo., [Methods and results] A wide dataset that comprised yield components and grape composition of 531 cv. Tempranillo accessions for seven years was used, comparing their performance depending on the presence of each virus. GFLV showed the highest deleterious effects, followed by GLRaV-3, whereas GFkV had no effect. GLRaV-3 and, especially, GFLV effects were very relevant., [Conclusions] Regression analyses demonstrated that GFLV increases soluble solids (TSS) and colour density (CD) independently of yield reduction or advanced ripening, and causes higher pH independently of TSS. Similarly, GLRaV-3 detrimental effect on CD is not caused only by delayed ripening, and higher pH is associated to imbalanced ripening., [Significance of the study] Our results highlight that a detailed analysis of a wide agronomic dataset allows a better understanding of virus diseases, unveiling to which extent some of their effects are direct or indirect., This work has been performed within the following projects: “Selección y mantenimiento en campo de fenotipos del cv. Tempranillo de la D.O.Ca. Rioja; estudio de su contenido fenólico y mejora de su extracción” (1998, CDTI/ADER) and “Creación de un banco de germoplasma de cv. Tempranillo de Rioja. Contenido fenólico de las variedades autóctonas, optimización de la extracción y estabilización”. VIN00-043-C3 (2000, INIA).

4 Pags.- 2 Tabls. Articles derived from XIV EUCARPIA Symposium on Fruit Breeding and Genetics (Bologna,Italy. June 14-18 2015) . The definitive version is available at: http://www.actahort.org/index.htm, The description of phenotypic traits in apple cultivars is generally performed using internationally agreed descriptors such as UPOV guidelines, which defines for each trait several states of expression. However, it is not always possible to classify a cultivar unambiguously using those guidelines, because in practice the states are not clearly enough defined or the example cultivars are not always available in the collections. This work presents the results of a harmonization project performed by the teams responsible of the main apple germplasm collections in Spain. The objective was to develop a standardized method for the 57 traits included in the TG/14/9 UPOV guidelines for apple characterization, defining their states of expression in a clear and unambiguous way for Spanish germplasm. Phenotypic data collected for more than 1,600 accessions from Spanish collections were used and the method to define each state depended on the type of expression. For quantitative traits the number of states and their limits were defined according to the variability that exists within and between accessions. For qualitative traits, high-resolution images clearly depicting each state were selected. A standardized characterization protocol for the 57 traits of apple germplasm has been provided, enabling to comparing properly the phenotypes of Spanish genetic resources., This Project has been funded by the Spanish Ministry of Science and Innovation/National Institute for Agricultural and Food Research and Technology (RF2011- 00017-C05-00).

Early definition of oenologically significant zones within a vineyard is one of the main goals of precision viticulture, as it would allow an increase in profitability through the adaptation of agronomic practices to the specific requirements of each zone, and/or segregation of the harvest into different batches to produce wines with different qualities. The aim of this work was to evaluate whether early grape sampling is a relevant tool for within-vineyard zone definition. The study was carried out in 2010 and 2011 in a 4.2 ha vineyard, where a grid of 60 sampling points was defined. 300-berry samples were picked from each sampling point after veraison and at harvest, post-veraison information being used to define zones within the vineyard after fuzzy k-means analysis and subsequent application of a zoning procedure that took into account membership degree and neighbourhood criteria. Two variations of the zoning procedure were used, standard (StdZ) and top (TopZ) zoning. Each was designed to meet different requirements of wineries; StdZ gave the same oenological relevance to all the zones, and TopZ differentiated the zones producing 'top class' grapes, minimizing the within-zone variability in the top-class zone. Grape composition obtained at harvest from the zones delineated post-veraison was compared. Zone delineation using post-veraison data was proved to be oenologically relevant, provided sampling is performed once veraison is completed. The two zoning algorithms designed were shown to be suitable for objective zone delineation according to the goals intended for each. This work was funded by the Dpt. Innovación, Industria & Empleo of the Government of Navarra (MODELVID, Ref: IIM11879.RI.1), by the Centro para el Desarrollo Tecnológico Industrial CDTI (Ref: IDI-20100729, co-funded by the European Union ERDF as part of the Operational Programme I+D+i Technology Fund 2007-2013) and by Fundación Fuentes Dutor. I.U. The Spanish Ministry of Education funded I.U. stage in SupAgro, Montpellier (EDU/2719/2011).