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Water potential is considered to be the “gold-standard” measure for plant water status determination. However, there are some discrepancies on how and at what time of the day water potential measurements should be performed in order to obtain meaningful information. The aim of this work is to evaluate the discrimination ability of water potential measurements in grapevines depending on the time of the day and of the measurement procedure (leaf vs. stem). To do so, a meta-analysis was performed using >78,000 measurements of water potential data obtained in field irrigation experiments, provided by 13 research teams working in this subject in Spain. For each measurement day and experiment, Discrimination Ratio (DR) was calculated and used to determine the discrimination ability of each method, and then pooled for comparison. The measurement procedure with the greatest DR can be hypothesised to be the most suitable under the average working conditions. Leaf water potential showed lower DR mean values than predawn or stem water potential. The climatic conditions and the cultivar may affect to the discrimination ability, although the abovementioned trend was always maintained. Leaf water potential in vineyards should therefore be replaced, as a general rule, by either stem or predawn water potential readings, without a clear pre-eminence of the performance of predawn and stem water potential measurements. Building a common dataset and its subsequent meta-analysis has been proved to be an efficient and robust tool to compare plant measurements, and should be implemented for other species and/or measurement procedures.

Viticulture in Southern Europe heads towards a scenario of drier and warmer the growing seasons due to climate change. This decrease in the amount of water available for the vines and increase in evapotranspiration make necessary finding strategies to reduce vineyard water needs. In this context, the effect of severe trimming (40–60% of shoot length), performed at pea-size stage, on plant water status was evaluated in four different vineyards located in North of Spain. Severe trimming improved plant water status clearly only when climate conditions were more demanding, whereas only a slight improvement or no change was observed elsewhere. Lower leaf areas resulted in less water deficit following a logarithmical trend revealing that the effect was more pronounced at low leaf area levels. Severe trimming had non-significant effects on cluster number, yield and cluster weight, but presents a tendency to reduce total soluble solids content and to increase total acidity, consequently delaying ripening.

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.

The reconstitution of European vineyards after the phylloxera outbreak was performed with few high-aptitude varieties. In Navarre (Spain), the variety used was mainly ‘Garnacha’, though the inclusion of a small number of plants of different varieties traditionally grown in this area within each vineyard was relatively frequent. In this context, in 2008 and 2009, a systematic survey was performed on the oldest vineyards (>50 years) from Navarre in order to gather the intravarietal diversity that could be found within ‘Garnacha’ in the region, but subsequent field observation showed 197 plants to be different from ‘Garnacha’. The aim of this study was to identify the varieties corresponding to those plants. Molecular profiles were determined using 25 SSR markers, and 33 varieties were identified: 28 of them after comparisons with national and international databases and the remaining five through other sources. Slight differences in SSR allele length were found in some of the plants identified as ‘Mazuelo’, ‘Rojal’, ‘Miguel de Arco’ and ‘Tortozona Tinta’. In addition, polymorphisms involving the appearance of a third allele were found in some plants identified as ‘Viura’, ‘Mandon’, Mazuelo’ and ‘Morate’. This study shows that an important biodiversity reservoir still remains within old vineyards and, therefore, systematic surveys on them could allow gathering the varietal richness that still can be found in the region. Additionally, somatic variation at SSR loci has been shown to occur in several grape varieties, especially in the ancient ones where the likelihood that mutations are accumulated and fixed is higher.

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.

The study of the natural abundance of stable isotopes in grapevine organs and tissues started in the late 1970s and, since then, a significant body of research has analysed how cultivar, rootstock, climate, soil and growing conditions affect the relative proportion of the stable isotopes of carbon (δ13C), oxygen (δ18O) and hydrogen (δD) in grapevine organs. Besides, some research has been devoted to the study of the isotope ratios of nitrogen (δ15N), strontium (δ87Sr), boron (δ11B) and sulfur (δ34S) in vineyards. This review presents the state of the art of stable isotope determination in viticulture, and outlines some approaches that, to date, have not been considered in viticulture and that could be applied in future research.

Phenological models provide an assessment on the adaptation of species and cultivars to current conditions as well as the on the impact climate change may have on their performance in the future. The aim of this study was to obtain phenological models that predict accurately peach bud development for reference cultivars in temperate growing areas. Model testing and validation were done using phenological observations from orchards in Ebro and Guadiana Valleys, two of the main peach growing areas in Spain, where chilling accumulation ranges from medium to high. Data were acquired during 6 years for three widely grown cultivars (Big Top, O’Henry, and Andross). Two different types of models were tested: Critical Date models (CD), which consider only the action of forcing temperatures accumulated from a fitted date, and Critical Chilling models (CC), which also take into account the action of chilling temperatures during the dormancy period. CC models were always at least a 40% more efficient than CD ones and the version which uses the Dynamic method to estimate chill (CC DY ) had also the best accuracy with prediction errors generally around four days, so it was chosen as the best model. The validation process showed adequate accuracy and no significant predictive bias. The fitted values for CC DY parameters also had physiological sense, as the chilling values at which forcing heat began to accumulate were in accordance with the limit in which additional chilling is known to have little effect on heat requirements; and fitted threshold temperature for forcing heat accumulation was nearly the same considered to be the physiological base temperature for this species (4.7 °C). On the contrary, CD models fitted threshold temperatures for bud development inconsistent with peach physiology (between −6 and 0 °C) and were poorly adapted to predict phenological stages at a regional scale. All in all, the results showed that phenological evolution of peach cultivars can be simulated with good accuracy using simple sequential statistically fitted models that include chilling evaluated by Dynamic method and forcing heat accumulation evaluated by growing degree sums. These models could be used to estimate the phenological evolution of peach under a wide range of climatic situations, including the evaluation of the impact climate change scenarios may have on the phenology of the crop.

BACKGROUND Sample freezing is frequently used in oenological laboratories as a compromise solution to increase the number of samples that can be analysed, despite the fact that some grape characteristics are known to change after frozen storage. However, freezing is usually performed using standard freezers, which provide a slow freezing. The aim of this work was to evaluate whether blast freezing would decrease the impact of standard freezing on grape composition. RESULTS Grape quality parameters were assessed in fresh and in frozen stored samples that had been frozen using three different procedures: standard freezing and blast freezing using either a blast freezer or an ultra-freezer. The implications of frozen storage in grape samples reported in earlier research were observed for the three freezing methods evaluated. Although blast freezing improved repeatability for the most problematic parameters (tartaric acidity, TarA; total phenolics, TP), the improvement was not important from a practical point of view. However, TarA and TP were relatively repeatable among the three freezing procedures, which suggests that freezing had an effect on these parameters independently of the method used . According to our results, the salification potential of the must is probably implied in the changes observed for TarA, whereas for TP the precipitation of protoanthocyanins after association with cell wall material is hypothesized to cause the lack of repeatability between fresh and frozen grapes. CONCLUSIONS Blast freezing would not imply a great improvement if implemented in oenological laboratories, at least for the parameters included in this study. © 2013 Society of Chemical Industry

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).

Carbon isotope ratio (δ 13 C) is known to be related to water use efficiency and water status in grapevines. However, there is no consensus on which is the temporal sensitivity of this parameter, i.e. which is the time-span this parameter integrates best. The aim of this work was to evaluate the usefulness of whole berry δ 13 C to integrate plant water status in grapevine, and to determine its temporal sensitivity. Comparing δ 13 C of berries sampled 10 days after veraison and at harvest with average stem water potential at different moments of the season; we observed that the moment at which water deficit occurs remarkably conditioned the response observed. The moments for which the sensitivity was greatest were two periods critical for sugar accumulation: veraison and 4–6 weeks before harvest. This gives a particular relevance to δ 13 C measured in whole berries, as its sensitivity is higher at critical moments of berry ripening, but it also implies that care has to be taken when interpreting δ 13 C values, considering the variations in sensitivity depending on sampling time.

A set of 493 old and local Spanish accessions of apple (Malus x domestica Borkh) maintained at three collections in Northeastern Spain was studied using 16 simple sequence repeats in order to estimate their genetic diversity and to identify the genetic structure and relationships among their accessions. An additional diverse set of 45 apple cultivars, including old Spanish and international cultivars, was added as reference. Genetic analyses performed by Bayesian model-based clustering revealed a very strong differentiation of two major groups. The first one clustered 159 individuals (52 % of unique genotypes) including local accessions and six old Spanish cultivars. The second major group was formed by 145 individuals, including 38 international reference cultivars and one old Spanish cultivar. Nested Bayesian clustering was applied to those two groups and two and four sub-groups were found at each one, respectively. The identification of private and unique alleles, and the remarkable differences in allelic richness among groups and sub-groups constitute further evidence of a clear genetic structure. The results obtained through the factorial correspondence and analyses of molecular variance confirmed those obtained by Bayesian analyses, revealing moderate but significant differentiation among the two major groups (F ST = 0.076) and the six sub-groups (F ST = 0.111). Our results highlight that the genetic diversity encompassed by currently cultivated apple accounts only for a small fraction of that existing within the species, and that an important part (≈60 %) of the local material analyzed constitutes a good example of genetic distinctness with respect to the main cultivars used in European orchards.

Grape must and wine colour is traditionally assessed by several indexes calculated after measuring absorbance at 420, 520 and 620 nm. In the last years tristimulus colorimetry (mainly CIELab colour space) is increasingly used in research and wineries, since it seems to be a more accurate method to evaluate wine colour, especially at hue junctions when visual colour is quite subjective. The aim of our work is to compare CIELab parameters (L*, c*, h) to classical colour indexes in grape must. Total (TAnt) and extractable (EAnt) anthocyanin content was measured in more than 1600 samples of 4 cultivars ('Cabernet Sauvignon' - CS, 'Grenache' - GA, 'Graciano' - GR, and 'Tempranillo' - TE) at 3 stages of ripening by Glories method. In the same macerated extracts, tristimulus colour measurements were made with a Minolta reflectance spectrophotometer, using 2 and 10 mm path length quartz glass cells. Luminosity has been the parameter that has allowed the best estimation of TAnt and EAnt. However, the correlation coefficient found for EAnt was relatively low (R2=0.75) due to differences between cultivars; GA and GR showing lower luminosity for a given EAnt value than CS and TE. These differences are probably a result of differences in the anthocyanic profile of these cultivars, which may affect directly (differences in absorbance pattern) or indirectly (co-pigmentation and self association process) the colour when the whole spectrum is taken into account. Colorimetic measurements have been shown to allow estimating the classic colour parameters (provided varietal differences are considered) and to detect more subtle differences between samples.

Background and Aims: In viticultural and oenological research, grape samples are frequently stored frozen to overcome time and facility restraint. However, there is little knowledge on how freezing, variety and storage time affect the changes occurring in grape quality parameters. The aim of the paper was to evaluate these effects using cv. Cabernet Sauvignon (CS), Grenache (GA) and Tempranillo (TE) samples. Methods and Results: Quality parameters were assessed in fresh grapes and after 1, 3 and 6 months of frozen storage. Soluble solid concentration remained unchanged. Freezing decreased titratable and tartaric acidity. pH increased after 1 and 3 months of storage, but decreased after 6 months. Freezing increased malic acid concentration only in GA. Yeast assimilable nitrogen diminished with freezing time, with each variety behaving differently. A significant colour enhancement was found (EAnt, L*, C*), whereas degradative reactions for polyphenols occurred at any storage time for GA, and for all varieties after 6 months. Conclusions: Variety and storage time play a large role in the changes occurring in stored frozen grape samples. Not considering these factors may lead to misinterpretation of results obtained through subsequent use of these grapes. Significance of the Study: Specific correcting factors for each quality parameter, variety and storage time are needed when working with stored frozen samples.

Regulated Deficit Irrigation (RDI) is an irrigation scheduling technique, originally developed for fruit orchards, that has been successfully adapted for winegrape production. The aim of this work is to evaluate the effect of RDI in vegetative growth, yield and harvest quality in ‘Tempranillo’ vineyards grown under semiarid conditions typical in Mediterranean areas. Two RDI strategies were compared with conventional irrigation practices (CI). CI that consisted in a progressive increase in water deficit as summer progressed, whereas RDI strategies (RDI1 and RDI2) had in common a deficit period just after fruit set and, in RDI2, vines were subjected to an additional stress period shortly after veraison. The experiment was carried out in four consecutive seasons in a commercial vineyard. Water stress at the beginning of berry development resulted in an important reduction of both vegetative growth and berry weight in RDI strategies. No differences in sugar concentration were found between treatments, and RDI berries tended to have lower acidity. The most relevant effect of RDI strategies on grape quality was an increase in anthocyanin and phenolics concentration. In RDI1 berries, this increase was mainly an indirect consequence of smaller berry size. However, in the RDI2 treatment the higher berry anthocyanin concentration reported was not exclusively due to a reduction in berry size. Since harvest quality has been clearly improved by any of the RDI strategies in both years, it can be concluded that RDI constitutes an interesting technique to be applied in ‘Tempranillo’ vineyards grown in semiarid areas aiming to obtain high quality grape.

Background and Aims: Irrigation management requires the collection of up-to-date information that allow growers to make rapid decisions, water potential being one of the most used parameters in irrigation scheduling. The goal of this research was to determine whether predawn (Ypd) and stem (Ys) water potential can be used equally well, quantifying the effect external factors have on the relationship between them. Methods and Results: Ypd, mid-morning (Ys-m) and noon (Ys-n) stem water potential were measured at seven cv. Tempranillo vineyards. Climatic conditions, vine growth and fruit load affected daily water potential dynamics. A greater decline of Ys occurred when temperatures were higher and there was no dew formation, as well as under larger canopies and fruit load. While the relative impact of these variables on water potential was not particularly high, it was by no means negligible. Conclusions: Data collected in this study did not favour Ypd, Ys-m or Ys-n as a preferred measure to evaluate plant water status. It is important to remark that similar Ypd values do not necessarily indicate the same level of deficit, and that similar Ys values do not always mean similar water availability. Therefore, a straightforward interpretation of Ypd and Ys can sometimes be misleading. Significance of the Study: The results obtained provide significant explanation to the lack of agreement in the literature regarding the most suitable time to measure water potential. Vineyard managers and scientists should select it according to the level of stress expected, climatic conditions and irrigation frequency. Abbreviations BN berry number; DR discriminating ratio; ET evapotranspiration; LWD leaf wetness duration; YL leaf water potential; Ypd pre-dawn leaf water potential; Ys-m mid-morning stem water potential; Ys-n stem water potential at noon; SBA sum of shoot basal cross-sectional area; VPD vapour pressure deficit.

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).

The influence of the species in spring frost sensibility was determined for the Prunus species peach (P. persica (L.) Batsch), sweet cherry (P. avium L.), almond (P. dulcis (Mill.) Webb/P. amygdalus Batsch), japanese plum (P. salicina Lindl.), and blackthorn (P. spinosa L.). The confidence intervals for lethal temperatures of 10% (LT10) and 90% (LT90) bud injury were also determined. In 2000 and 2001, seven frost treatments were made for each one of the phenological stages comprised between B (first swell) and I (jacket split) in two cultivars per each species. The relationships between frost temperature and the proportion of frost damaged buds for each cultivar, year, and phenological stage were adjusted to linear regression models. The 95% confidence intervals were also calculated. The spring frost hardiness order of the species, from the least to most hardy, was as follows: sweet cherry, almond, peach, japanese plum, and blackthorn. Despite the highly homogeneous nature of the frost and bud characteristics, the temperature range for a given injury degree was quite broad, since the confidence interval's breadth for LT10 was as high as about 3 °C and as high as about 6 °C for LT90. Consequently, when critical temperatures are used in making decisions as to when to begin active frost protection, a prudent measure would be to take the temperature references from the upper limits in the confidence intervals.

Determination for the genetic variability on species such as cardoon (Cynara cardunculus L.) allow the evaluation of their aptitude in genetic improve, and so shorten the time needed in the process. In this work 17 local population were evaluated, 13 from the germplasm bank located in Zaragoza and 4 selections from "Verde de Peralta". Analysis was performed trough 80 RAPD markers. Population homogeneity was fairly high: intra-cultivar similarity was above 0.83 except for 'Sin Pincho' from Segovia, and in the 'Seleccion 1er ano ITGA' from Navarre. The latter cultivar was selected according to industrial criteria and in the second year of improvement their homogeneity was similar to the rest, so that characters used in the selection were genetically regulated. Inter-cultivar variability suggests that this specie is fairly homogeneous. Cluster analysis showed three well-defined groups, one including all the cultivars from the mid-Ebro Valley, a second one with segovian populations and a third with the rest.

Fingerprinting information can be used to elucidate in a robust manner the genetic structure of germplasm collections, allowing a more rational and fine assessment of genetic resources. Bayesian model-based approaches are nowadays majorly preferred to infer genetic structure, but it is still largely unresolved how marker sets should be built in order to obtain a robust inference. The objective was to evaluate, in Pyrus germplasm collections, the influence of the SSR marker set size on the genetic structure inferred, also evaluating the influence of the criterion used to select those markers. Inferences were performed considering an increasing number of SSR markers that ranged from just two up to 25, incorporated one at a time into the analysis. The influence of the number of SSR markers used was evaluated comparing the number of populations and the strength of the signal detected, and also the similarity of the genotype assignments to populations between analyses. In order to test if those results were influenced by the criterion used to select the SSRs, several choosing scenarios based on the discrimination power or the fixation index values of the SSRs were tested. Our results indicate that population structure could be inferred accurately once a certain SSR number threshold was reached, which depended on the underlying structure within the genotypes, but the method used to select the markers included on each set appeared not to be very relevant. The minimum number of SSRs required to provide robust structure inferences and adequate measurements of the differentiation, even when low differentiation levels exist within populations, was proved similar to that of the complete list of recommended markers for fingerprinting. When a SSR set size similar to the minimum marker sets recommended for fingerprinting it is used, only major divisions or moderate (FST>0.05) differentiation of the germplasm are detected. This study was funded by INIA, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (Project grant number RF2004-008-C03- 00) (JBR), for the consumables and SSR analyses, and internal University funding.

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).

In the last decades, viticultural research has made important progress due to the implementation of many technical advances to this field. In addition to “classical” viticultural research, it is now possible to analyze vine behaviour with many different approaches, such as plant physiology, genomics, proteomics, precision viticulture and so on. These changes extend our understanding of viticulture, but they may also lead to a certain heterogeneity in the methodology used to estimate the basic characteristics of the vineyards (e.g.: vegetative and reproductive growth). Even worse, measurements of those parameters are sometimes neglected. In order to optimize the relevance and inter-disciplinarity of our work, and its applicability to the vineyard, we should tend toward protocol standardization, the most suitable measurements and ways of expressing results should be determined for each circumstance. This chapter attempts to shed some light on some methodological aspects related to the measurement of vine vegetative and reproductive growth and vineyard balance. We have tried to be comprehensive, but not exhaustive, since some topics are also the subject of other chapters in this book whereas others are beyond its scope.

11 Pags.- 6 Tabls.- 2 Figs., Isoenzymes from grapevine woody stems and shoots were evaluated for their use in identification of varieties and clones. Plant extracts were separated by polyacrylamide gel electrophoresis. Isoenzyme analysis was carried out for esterases, peroxidases, catechol oxidase, glutamate oxalacetate transaminase and acid phosphatase. The plant material was grown and sampled at two localities in Spain, with different climatic conditions. Sampling was carried out bimonthly for two consecutive years in order to find out the influence of the environment and time of the year. Each isozyme system had a pattern defined by ‘fixed’ bands, that were always present at both localities and during the resting period of the plant (fall—winter). Esterases had a pattern with very few ‘fixed’ bands. Catechol oxidase was the most polymorphic system, thus being highly discriminating. The studied isoenzyme systems gave differences among varieties, although not among clones of the same variety. The use of this methodology for identification of grapevine plant material is discussed., This study has been carried out with financial support provided by 'Comisión Interministerial de Ciencia y Tecnologia' (C.I.C.Y.T.), Project AGR 0070-91-C01-C02.

Las colecciones nucleares de plantas pueden formarse a partir de la información obtenida en caracterizaciones morfológicas, agronómicas o eco-geográficas, así como a partir de caracterizaciones bioquímicas o moleculares. Un aspecto poco estudiado de la formación y validación de colecciones nucleares es la capacidad de éstas para conservar la estructura y diversidad de la colección global en aquellos caracteres que no han sido empleados para formar la colección nuclear. En el presente estudio se determinaron tres colecciones nucleares para el Banco de Germoplasma de Manzano de la Universidad Pública de Navarra: para el primero se emplearon los datos de caracterización de 10 marcadores SSR, la segunda fue formada a partir de la caracterización hecha con 12 loci de isoenzimas, y la tercera se construyó a partir de la información proporcionada por 23 caracteres morfo-agronómicos. Se comparó la estructura y diversidad genotípica y fenotípica de las tres colecciones, entre sí y respecto de la colección original, para determinar el impacto que sobre dicha estructura y diversidad tenía el tipo de dato con que se formó la colección nuclear. Las tres colecciones conservaron una diversidad similar y no difirieron de la original en sus índices de Nei y Shannon-Weaver, y siempre se mantuvieron las frecuencias de las clases alélicas o fenotípicas. En conjunto, el tipo de caracterización empleada en la formación de la colección nuclear tuvo escasa influencia sobre la diversidad retenida, de lo que se concluye que en el manzano los microsatélites son especialmente adecuados para formar dichas colecciones. Various types of data have been used for sampling plant core collections, including morphological, agronomic and eco-geographical traits, and molecular and biochemical markers. However, little is known about the ability of woody perennial core collections to retain the diversity and structure of the whole collection for characters that were not considered in the selection, especially when molecular markers are used. In this study, three core subsets were established for the apple germplasm bank curated at the Public University of Navarre (UPNa, Spain): based upon the diversity found with 10 SSR markers, another based upon the diversity assessed with 12 isozyme loci; and a third based upon morpho-agronomic diversity evaluated by 23 morpho-agronomic traits. Comparisons between these three subsets and to the whole collection were assessed to determine the impact of the data used in the selection on phenotypic and genetic diversity and on their population structure. The three subsets had a similar diversity and they did not differ from the original collection, according to Nei and Shannon-Weaver indices. The allelic/class frequencies were also always maintained in the three subsets. Overall, the kind of data used to constitute a core collection had little influence on the phenotypic and genetic diversity retained, so in the case of apple collections the use of molecular markers is preferable for this task because they allow a rapid and reliable characterization. This study was funded by the Spanish Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) grants Nº RF200400008-C03-00 and Nº RFP2004-00003-00-00.

A collection of 141 old and local Spanish accessions of pear (Pyrus communis) from the Escuela Tecnica Superior de Ingenieria Agraria-Universidad de Lleida (ETSIA-UdL) Pear Germplasm Bank in Lleida, Spain, were studied using a set of eight microsatellite markers to estimate the genetic diversity of the collection, to identify the genetic structure and relationships among its accessions, and to establish a representative core collection. An additional set of 13 well-known pear cultivars, currently grown in Spain and which represent a wide genetic diversity, were added as reference. The eight simple sequence repeat (SSR) loci amplified 97 alleles, with nine to 15 alleles per locus, and with the expected heterozygosity ranging from 0.65 to 0.89. All of the accessions except for 16 had at least one of the 48 rare alleles (frequency < 0.05) identified, and seven unique alleles were found in six accessions. Fifteen accessions were identified as synonyms and were excluded from the analysis. Genetic analyses performed by hierarchical clustering, Bayesian modelbased clustering, and factorial correspondence analysis supported the existence of three groups among the accessions with moderate [fixation index (FST) = 0.074], but significant, differentiation. As a whole, most of the germplasm (about 75%) curated at the collection showed its genetic distinctness with respect to the main pear cultivars used in European orchards. In fact, most reference cultivars were included in one single cluster that, moreover, had the lowest genetic diversity and allelic richness, in spite of having been chosen as heterogeneous material from different origins. The obtained results were also used to create a core collection with 35 accessions constituting an efficient and accessible entry point in the ETSIA-UdL pear collection for breeding and research communities. Pear (Pyrus spp.) is one of the most important fruit crops of the Rosaceae family, ranking second to apple (Malus ·domestica) in world and European production of pome fruit tree species (Food and Agriculture Organization of the United Nations, 2010). Pyrus communis is the most commonly cultivated pear species in Europe, America, and Africa, whereas Pyrus pyrifolia is the main cultivated species in Asia (Bell, 1991). Worldwide production of P. communis pears is based upon relatively few cultivars, most of them selected in late 18th and 19th century, or derived from those. Furthermore, the genetic base of cultivated pear in western Europe has significantly narrowed in the last few years. In 1986, seven cultivars accounted for 58% of pear production in western Europe (Bell, 1991), but nowadays, seven cultivars account for 75% of the production (World Apple and Pear Association, 2009). ‘Conference’ has become predominant in most European producing countries, and accounts for nearly one-third of European Union production. The reasons for this concentration are varied, but include economic and market factors, changes in consumption patterns, and biological aspects, such as productivity, storage ability, and susceptibility to pests and diseases (Bell, 1991). As a consequence, many of the traditional or local cultivars have been considered obsolete and replaced, leading to a dramatic loss of genetic diversity. The recognition of the need for the collection and preservation of endangered fruit germplasm has encouraged the establishment of genetic resource conservation programs. In 1986, a germplasm bank of old and local pear cultivars was established by the Horticulture section of the ETSIA-UdL. This germplasm bank currently maintains 114 Malus and 169 Pyrus accessions, collected at 12 northern Spanish provinces (Urbina et al., 2007), at the Estacion Experimental de Lleida of the Institut of Recerca i Tecnologia Agroalimentaria (IRTA) in Lleida, Spain. In 2002, a research program was launched to evaluate the genetic diversity of the collection through detailed morphological and agronomical description, and fingerprinting analysis based upon molecular markers was initiated in 2005. Microsatellite or simple sequence repeat (SSR) markers have been favored over other methods in establishing unique genetic identities or fingerprints and in assessing genetic diversity within a collection due to their high polymorphism level, reproducibility, and relative ease of analysis (Schlotterer, 2004). Moreover, SSR have also proven useful in creating core collections that represent not only the genetic structure of germplasm collections, but also their phenotypic structure (Santesteban et al., 2009). The SSR markers used in the earliest studies in pear were derived from apple (Yamamoto et al., 2001; Hemmat et al., 2003), as apple proved to be highly conserved in pear. However, after the development of SSR derived from asian pear (P. pyrifolia) and Received for publication 10 May 2010. Accepted for publication 28 June 2010. Financial support for this work was provided by INIA, Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (project grant nos. RF2004008-C03-00, RFP2004-009, and RFP-0000-68). Corresponding author. E-mail: carlos.miranda@unavarra.es. 428 J. AMER. SOC. HORT. SCI. 135(5):428–437. 2010. Table 1. Pear accessions maintained by the Escuela Tecnica Superior de Ingenieria Agraria Universidad de Lleida (ETSIA-UdL) Germplasm Bank and reference cultivars that were included in the study, in alphabetical order. Accessions selected to constitute the core collection are indicated in bold. Collection information includes accession name and bank code, site of collection, specific latitude and longitude, approximate elevation, and collecting source code according to Food and Agriculture Organization of the United Nations/International Plant Genetic Resources Institute (FAO/IPGRI, 2001) multicrop passport descriptors. Accession name Accession code Site of collection in Spain Latitude Longitude Elevation (m) Collecting source Agramunt 1 PRF-135 Puigvert d’Agramunt, Lleida 41.78 1.13 360 23 Agua PRF-030 Nalda, La Rioja 42.33 –2.48 530 23 Agua Iglesia PRF-028 Lardero, La Rioja 42.42 –2.45 435 23 Agua Magistral PRF-029 Lardero, La Rioja 42.40 –2.47 460 23 Aguilar 1 PRF-011 Aguilar de Campoo, Palencia 42.78 –4.25 900 23 Almenar 1 PRF-071 Almenar, Lleida 41.77 0.62 270 62 Angelina PRF-141 Isona i Conca Della, Lleida 42.08 1.12 1000 23 Areny 1 PRF-091 Areny de Noguera, Huesca 42.25 0.73 670 62 Areny 2 PRF-092 Areny de Noguera, Huesca 42.25 0.73 675 62 Areny 3 PRF-093 Areny de Noguera, Huesca 42.25 0.73 675 62 Areny 4 PRF-113 Areny de Noguera, Huesca 42.25 0.72 750 23 Azucar verde 1 PRF-007 Albelda de Iregua, La Rioja 42.37 –2.47 490 21 Azucar verde 2 PRF-008 Albelda de Iregua, La Rioja 42.37 –2.47 490 21 Balaguer 1 PRF-066 Balaguer, Lleida 41.75 0.77 220 23 Balaguer 2 PRF-067 Balaguer, Lleida 41.75 0.77 220 23 Balaguer Flix 1 PRF-046 Balaguer, Lleida 41.73 0.93 290 62 Balaguer Flix 2 PRF-047 Balaguer, Lleida 41.73 0.93 290 23 Balaguer Flix 3 PRF-048 Balaguer, Lleida 41.73 0.93 290 23 Balaguer Flix 4 PRF-049 Balaguer, Lleida 41.73 0.93 290 23 Balaguer Flix 5 PRF-050 Balaguer, Lleida 41.73 0.93 290 23 Balaguer Flix 6 PRF-051 Balaguer, Lleida 41.73 0.93 290 23 Balart PRF-070 Almenar, Lleida 41.77 0.58 280 23 Benavent de la Conca 1 PRF-142 Benavent de la Conca, Lleida 42.08 1.12 985 23 Bergamota PRF-112 Sopeira, Huesca 42.33 0.73 780 23 Bescano 1 PRF-121 Bescano, Girona 41.97 2.75 110 23 Bescano 2 PRF-122 Bescano, Girona 41.97 2.72 110 23 Biscarri 1 PRF-143 Biscarri, Lleida 42.12 1.12 920 23 Blanca d’aigua PRF-079 Baix Pallars, Lleida 42.33 1.0

The lowest flower in the pear (Pyrus communis L.) cluster usually develops and blooms first and also has a greater sink potential. For this reason, resources are preferentially utilized by the lowest fruit, and this is also one of the reasons why most thinning practices tend to favor their set. However, it is not always possible to perform selective thinning. This study was undertaken to determine if hindering pollination in the most developed flowers in the cluster influences yield or quality compared to that obtained in a whole open-pollinated cluster. The treatments were made in `Blanquilla' (Spadona, Agua de Aranjuez) and `Conference' pear within a wide range of flower densities for each cultivar. Pollination was hindered by cutting off the flower styles. The factor tested was style removal intensity (SRI). Treatments consisted in removing the styles of two, four(always the most developed), or all flowers in each cluster. Flower density was used as a covariate in an analysis of covariance to account for differences in flower densities in response to SRI treatments. In all experiments the covariate was not significant; therefore, SRI effect was not affected by flower density. `Blanquilla' and `Conference' had similar responses to treatments, so that when at least three flowers are susceptible to be openly pollinated, fruit set, seed content, and cluster yield were similar to control clusters, therefore the growth potential of fruit from partially damaged clusters in their most developed flowers is similar to undamaged open pollinated clusters. The reduced set of parthenocarpic clusters implies yield reductions ranging between 40% and 60% in `Conference', and up to about 60% in `Blanquilla'.

The apical or king (K) flower in the apple (Malus ×domestica L. Borkh.) cluster usually develops and blooms first and also has a greater sink potential. For this reason, resources are primarily used by the K fruit, and this is also one of the reasons why most thinning practices tend to favor K fruit set. However, it is not always possible to retain the K flower and remove the lateral ones. This study was undertaken to determine if the removal of the most developed flowers in the cluster influences yield or quality compared to that obtained in a whole cluster. The treatments were made in `Golden Delicious' and `Royal Gala' apple cultivars, within a wide range of flower densities for each cultivar. The factor tested was the intensity of flower removal (FRI); the treatments consisted in removing one, two, or three flowers in each cluster. Flower density was used as a covariate in an analysis of covariance to account for differences in flower densities in response to FRI treatments. In all experiments the covariate was not significant; therefore FRI effect was not affected by flower density. `Golden Delicious' and `Royal Gala' had similar responses to flower removal, so that when at least three flowers in a cluster remained, fruit set and cluster yield were similar to whole clusters. Only when two or fewer poorly developed flowers remained after FRI treatments, yield was reduced by as much as 25%. Fruit from FRI clusters were even heavier than those from whole clusters, due to reduced competition among the fruit, so that the growth potential of fruit from the first and second lateral flowers was similar to clusters with K fruit, in clusters where the K flower had been removed.