Open Access
Pollen viability, self-incompatibility, and a very singular S-allele structure between the reasons for the limited potential productivity of traditional Basque cider apple varieties
(Elsevier, 2023) Crespo Martínez, Sara; Oneka Mugica, Oihane; Laquidain Imirizaldu, María Jesús; Urrestarazu Vidart, Jorge; Santesteban García, Gonzaga; Miranda Jiménez, Carlos; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Cider regions conserve a broad diversity of traditional cultivars for which knowledge has hardly evolved. Key aspects of their reproductive biology are barely known, hindering improvement in orchard management and resulting in highly variable yields. In this study, we characterized key aspects of the reproductive biology of some traditional apple cultivars from the Basque-style cider-producing area in northern Spain (Basque Country and Navarre). We tested for pollen quality, self-compatibility, and cross-compatibility (S-genotyping). The pollen quality was good except for Urtebete, Errezila, Reineta Encarnada, and triploid varieties. Self-pollination results confirm the need for pollinators, as only Moko and Txalaka showed certain self-compatibility. Regarding Sgenotyping, the population proved very singular, with an atypically high frequency of S26, a frequent allele within crabapples, and the appearance of a novel unpublished allele (S60). The knowledge generated for this variety pool will contribute to a better choice of suitable pollinators, preventing the use of popular crabapple varieties that are demonstrated to be partly incompatible with them, and will lead to an increase in potential yields in the region.
Open Access
Four-year field study reveals variable effects of phytohormone- and natural-based elicitors on anthocyanin metabolism in Tempranillo grapes
(Wiley, 2025-08-08) Crespo Martínez, Sara; Torres Molina, Nazareth; Loidi Erviti, Maite; Miranda Jiménez, Carlos; Astráin, Jesús; Santesteban García, Gonzaga; Urrestarazu Vidart, Jorge; Institute for Multidisciplinary Research in Applied Biology - IMAB; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Gobierno de Navarra / Nafarroako Gobernua; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, OTRI 001-1365-2022-000273
OBJECTIVES/BACKGROUND: Climate change has raised concerns about the imbalance between anthocyanin and sugar levels in grapevines. High temperatures tend to reduce anthocyanin content by inhibiting its synthesis and increasing degradation, while simultaneously enhancing sugar accumulation. The application of elicitors, which promote the anthocyanin biosynthetic pathway, may help alleviate this imbalance. METHODS: To investigate this, a four-year field trial was conducted on Vitis vinifera cv. Tempranillo to assess the effects of four commercial products: two natural-based (an antioxidant-mannitol and an alginic acid-mannitol products) and two phytohormone-based (an abscisic acid and an ethephon-based products). The study evaluated the effect of these treatments on the phenyl propanoid pathway gene expression, various yield parameters, and the content of primary and secondary metabolites. RESULTS: Although none of the treatments consistently increased anthocyanin levels across seasons, the results varied depending on the year. Two products influenced some parameters in specific seasons: the ethephon-based product, which influenced the anthocyanin-to-sugar ratio through the reduction of TSS and induced the expression of key anthocyanin genes, and the natural-based antioxidant-mannitol product, which transiently increased the expression of some phenylpropanoid genes. CONCLUSIONS: None of the treatments increased anthocyanin levels across seasons. Ethephon (Fruitel) showed greater effectiveness under temperature stress and reduced sugar accumulation, which may be advantageous in a warming climate. Natural elicitors like antioxidant-mannitol elicitor (Vitalfit) had short-term effects on gene expression but no lasting impact on anthocyanins. Further research is needed to assess their influence on other polyphenols and their potential for commercial use.
Open Access
Recovery of ancient grapevine plant material in peri‑urban areas. A case of success in Pamplona (Spain) leading to the recovery of cv. Berués
(Elsevier, 2022) Crespo Martínez, Sara; Mayor Azcona, Blanca; Oneka Mugica, Oihane; Loidi Erviti, Maite; Villa Llop, Ana; Marín Ederra, Diana; Miranda Jiménez, Carlos; Santesteban García, Gonzaga; Urrestarazu Vidart, Jorge; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB; Agronomía, Biotecnología y Alimentación; Gobierno de Navarra / Nafarroako Gobernua
Viticulture was relatively important in the peri‑urban area of Pamplona till the end of the 19th century, but suffered a continued regression that has led to a nearly complete disappearance of vineyards. In this context, this work aims to evaluate the feasibility of recovering old grapevine germplasm in the peri‑urban area of Pamplona. The lack of a conventional source for recovering plant material (i.e. absence of old vineyards in the area) implied the need of designing an alternative prospecting procedure. This method included the analysis of the available historical information as open-access resources (orthophotos, land use maps and GIS applications) aiming to identify the areas with the highest probability of finding vines surviving from the general abandonment and uprooting of vineyards that had occurred in the 20th century. Based on the oldest on scale orthophoto available for Navarra, a vineyard land map of the peri‑urban area of Pamplona in year 1956 was built, allowing prospecting efforts to be focused on specific areas of primarily interest. Following this strategy, a total of 120 plants were collected, which corresponded to 44 genotypes. The most prominent achievement of this prospecting mission was the recovery of 15 accessions of Berués, a very old variety with a remarkable importance in the region according to old historical records, and considered to be disappeared. The methodology proposed was effective in searching for the oldest standing-alone plants surviving in the peri‑urban area of Pamplona, and may be adapted to assist the recovery of old grapevine germplasm in other currently non wine-growing regions/areas where viticulture was relevant some decades ago. © 2021
Open Access
Sampling stratification using aerial imagery to estimate fruit load in peach tree orchards
(MDPI, 2018) Miranda Jiménez, Carlos; Santesteban García, Gonzaga; Urrestarazu Vidart, Jorge; Loidi Erviti, Maite; Royo Díaz, José Bernardo; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
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 pixel -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 20–35% compared to completely randomized samples.
Open Access
Agronomic evaluation of eight 41 B × 110 richter grapevine genotypes as rootstock candidates for mediterranean viticulture
(KeAi Communications, 2023) Marín Ederra, Diana; Miranda Jiménez, Carlos; Abad Zamora, Francisco Javier; Urrestarazu Vidart, Jorge; Mayor Azcona, Blanca; Villa Llop, Ana; Santesteban García, Gonzaga; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Choosing the most appropriate rootstock(s) is a key decision for the profitability of vineyards; therefore, there must be a sufficient range of rootstocks in the market adapted to different environmental conditions and production objectives. However, rootstock-breeding programs have been scarce in recent decades, and most of the rootstocks used today were bred a century ago, when the needs of the sector were very different from today. In this work, we aimed to evaluate new rootstock candidates before their introduction in the market. An agronomic evaluation was conducted on eight novel rootstock genotypes obtained from the first generation of the cross-pollination of 41 B Millardet et de Grasset (41 B) and 110 Richter (110 R) grafted with ‘Syrah’ and ‘Tempranillo’ and planted in a typical vineyard of the Ebro Valley in Spain. During the four consecutive growing seasons (2016e2019), growth, yield and berry composition parameters at harvest were collected. A linear mixedeffects model was constructed, considering year and block as random effects. Multiple factor analysis and hierarchical clustering on principal components were performed to establish clusters of genotypes with similar behaviour. The rootstock candidates showed a very wide performance range compared to their parents. The trial allowed us to identify two very promising candidates (RG8 and RG10), whose registration as commercial rootstocks is already in progress.
Open Access
Genetic diversity of Spanish Prunus domestica L. germplasm reveals a complex genetic structure underlying
(Public Library of Science, 2018) Urrestarazu Vidart, Jorge; Errea, Pilar; Miranda Jiménez, Carlos; Santesteban García, Gonzaga; Pina, Ana; Producción Agraria; Nekazaritza Ekoizpena
European plum (Prunus domestica L.) is an ancient domesticated species cultivated in temperate areas worldwide whose genetic structure has been scarcely analyzed to date. In this study, a broad representation of Spanish European plum germplasm collected in Northeastern Spain and a representative set of reference cultivars were compared using nuclear and chloroplast markers. The number of alleles per locus detected with the SSR markers ranged from 8 to 39, with an average of 23.4 alleles, and 8 haplotypes were identified. Bayesian model-based clustering, minimum spanning networks, and the analysis of molecular variance showed the existence of a hierarchical structure. At the first level, two genetic groups were found, one containing 'Reine Claude' type reference cultivars altogether with ca. 25% of local genotypes, and a second one much more diverse. This latter group split in two groups, one containing most (ca. 70%) local genotypes and some old Spanish and French reference cultivars, whereas the other included 24 reference cultivars and only six local genotypes. A third partition level allowed a significant finer delineation into five groups. As a whole, the genetic structure of European plum from Northeastern Spain was shown to be complex and conditioned by a geographical proximity factor. This study not only contributes to genetic conservation and breeding for this species at the national level, but also supports the relevance of undertaking similar tasks of collection and characterization in other unexplored areas. Moreover, this kind of research could lead to future coordinated actions for the examination of the whole European plum diversity, to define conservation strategies, and could be used to better understand the genetic control of traits of horticultural interest through association mapping.
Open Access
Evaluating the influence of the microsatellite marker set on the genetic structure inferred in Pyrus communis L.
(Public Library of Science, 2015) Urrestarazu Vidart, Jorge; Royo Díaz, José Bernardo; Santesteban García, Gonzaga; Miranda Jiménez, Carlos; Producción Agraria; Nekazaritza Ekoizpena
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.
Open Access
fruclimadapt: an R package for climate adaptation assessment of temperate fruit species
(Elsevier, 2021) Miranda Jiménez, Carlos; Urrestarazu Vidart, Jorge; Santesteban García, Gonzaga; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Climate strongly determines the growing range of fruit plant species that can be grown successfully in an area, and also the cultivars that will perform best. Therefore, the assessment of the adequacy of a climate is critical for decision-making in the design of fruit orchards and vineyards, and also for the evaluation of the potential consequences of future climate on fruit production. Bioclimatic indices and plant phenology models are commonly used to assess the suitability of climate for growing quality fruit and to provide temporal and spatial information about regarding ongoing and future changes. In this paper, we present fruclimadapt, a flexible and versatile package in the R language that streamlines the assessment of climate adaptation and the identification of potential risks for grapevines and fruit trees. A core set of functions allows to assess climate adaptation of fruit tree species by calculating specific bioclimatic index values and to evaluate potential threats to yield and fruit quality. Three additional sets of functions have been included as companions to: i) downscale daily meteorological values to hourly data, ii) estimate winter chill and forcing heat accumulation and iii) estimate the occurrence of phenological phases. fruclimadapt is currently available from the CRAN website (https://cran.r-project.org/package=fruclimadapt).
Open Access
Exploring phenotypic diversity and stability of key traits for apple breeding in northeastern Spanish germplasm
(Frontiers Media, 2025-09-16) Bielsa González, Francisco Javier; Errea, Pilar; Pina, Ana; Iturmendi Vizcay, Nerea; Irisarri, Patricia; Navarro Huidobro, Montserrat; Castel, Lourdes; Urrestarazu Vidart, Jorge; Santesteban García, Gonzaga; Miranda Jiménez, Carlos; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD
Malus x domestica Borkh is a key temperate fruit crop globally, but climate change and market demands highlight the need to broaden its narrow genetic base. The collection and conservation of local germplasms support breeding efforts by enabling the development of resilient phenotypes with improved traits. Under this framework, a set of 130 apple accessions (recovered from Northeastern Spain and 14 commercial cultivars were analyzed in terms of 12 phenotypic traits (firmness, SSC, malic acid, enzymatic browning (EB) susceptibility, fructose and glucose content, and phenolic content in peel and pulp). A statistical framework was developed to assess trait stability under shifting climatic conditions and detect significant correlations between climatic variables and phenotypical performance of apple trees. The results revealed a wide phenotypical variation across the studied traits, with the distribution of physicochemical traits strongly influenced in a genotype-dependent manner. A correlation matrix was obtained for studied traits revealing positive correlations between harvest date and SSC, enzymatic browning and firmness. Furthermore, uni- and multifactorial ANOVA revealed that genetic group (GG) is a key factor influencing all measured traits, especially pH, SSC, EB, and browning speed. Several interaction effects were also statistically significant, especially those involving ploidy level, which strongly influenced malic acid content and EB responses. Additionally, significant differences in fructose content were observed depending on peel coloration, and year-to-year phenotypic variation appeared to be predominantly governed by genotypic response to environmental conditions. Moreover, obtention of a mean stability index (Di) for each trait allowed the identification of ‘Pinova’,’Fuji’ and ‘Gala’ as the most stable cultivars among 11 commercial cultivars. These findings will support future research on development of functional cultivars and selection of ideal genotypes under shifting conditions.
Open Access
Severe trimming and enhanced competition of laterals as a tool to delay ripening in Tempranillo vineyards under semiarid conditions
(Université de Bordeaux, 2017) Santesteban García, Gonzaga; Miranda Jiménez, Carlos; Urrestarazu Vidart, Jorge; Loidi Erviti, Maite; Royo Díaz, José Bernardo; Producción Agraria; Nekazaritza Ekoizpena; Gobierno de Navarra / Nafarroako Gobernua
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.