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Plants constitute dynamic systems with different strategies to face biotic and abiotic stress. Water deficit is one of the most challenging abiotic factors increased by climate change, affecting seriously the quality of soils and crop yields, decreasing photosynthetic rate, increasing the accumulation of free radicals, and modifying root morphology. In this regard, the potential role of the host plant - arbuscular mycorrhizal fungi (AMF) and plant growth-promoting bacteria (PGPB) interactions within the rhizosphere in the alleviation of drought stress is being deeply studied. These symbiotic relationships not only allow a major nutrient and water uptake, but also could be integrated as a sustainable approach to improve the growth and productivity of crops under water scarcity conditions. A better comprehension of the mechanisms of these synergies between PGPB and AMF with plants is becoming an important key to develop effective applications of these natural symbiosis. In this work, the highlighted knowledge concerning these associations and their effect in the response of plants under drought stress have been reviewed, focusing on the interactions described in Solanaceae vegetables, one of the most relevant crops in the Mediterranean area.

In a climate change scenario, crop tolerance to drought must be urgently improved, as it represents an increasingly critical stress reducing agricultural yields worldwide. Although most crops are relatively sensitive to water stress, many of their wild relatives are more tolerant and may be used to improve drought tolerance in our crops. In this study, the response to drought of eggplant (Solanum melongena), its close wild relatives S. insanum and S. incanum and their interspecific hybrids with S. melongena was assessed. The plants were subjected to two treatments for 18 days: control, with irrigation every four days, and drought, with complete interruption of irrigation. Morphological and biomass traits were measured, and physiological and biochemical responses were analysed using stress biomarkers such as proline, flavonoids, and total phenolic compounds. Oxidative stress was quantified by measuring malondialdehyde (MDA) content. As a result of the drought treatment, plant development and tissue water content were seriously affected. Generally, water deficit also caused significant increases in MDA, proline, flavonoids, and total phenolics compounds. Our results comparing parental accessions reveal a better response to drought in one of the S. insanum accessions. The hybrid between S. melongena and S. incanum displayed a better response than the other hybrids and even its parents. The results obtained here might be helpful for future eggplant breeding programmes aimed at improving drought tolerance.

Modern agriculture has boosted the production of food based on the use of pesticides and fertilizers and improved plant varieties. However, the impact of some such technologies is high and not sustainable in the long term. Although the importance of rhizospheres in final plant performance, nutrient cycling, and ecosystems is well recognized, there is still a lack of information on the interactions of their main players. In this paper, four accessions of pepper are studied at the rhizosphere and root level under two farming systems: organic and conventional. Variations in soil traits, such as induced respiration, enzymatic activities, microbial counts, and metabolism of nitrogen at the rhizosphere and bulk soil, as well as measures of root morphology and plant production, are presented. The results showed differences for the evaluated traits between organic and conventional management, both at the rhizosphere and bulk soil levels. Organic farming showed higher microbial counts, enzymatic activities, and nitrogen mobilization. Our results also showed how some genotypes, such as Serrano or Piquillo, modified the properties of the rhizospheres in a very genotype-dependent way. This specificity of the soil–plant interaction should be considered for future breeding programs for soil-tailored agriculture.

[EN] Background and aims: Morphological and biochemical traits of four halophytes of the genus Limonium were analysed in plants sampled from salt marshes in SE Spain. This work aimed to explore the mechanism(s) behind the adaptation of these species to stressful habitats, with particular emphasis on responses to drought. Methods: Plants of each species together with soil samples were collected in summer, which is the most stressful season in the Mediterranean. Soil parameters and plant morphological traits were determined, and the levels of several biochemical stress markers in plants were measured using spectrophotometric assays. A multivariate analysis was performed to correlate soil and plant data. Results: Morphological characteristics regarding the underground system topology and several biochemical traits (higher foliar Ca2+, sucrose and glucose, and lower proline, glycine-betaine and fructose) clearly separate L. santapolense individuals from plants of the other three species. Conclusions: Drought tolerance of L. santapolense in the field is mostly dependent on morphological adaptations: when growing in an arid location, plants of this species develop long taproots that can extract water from the deep, moist layers of the soil., This research was partly supported by the project AICO/2017/039 from Generalitat Valenciana. We are indebted to Dr. Inmaculada Bautista (Universitat Politècnica de Valencia, Spain) for her useful suggestions for improving the manuscript.

[EN] Capsicum (pepper) is known for its poor seed germination, particularly seed longevity is usually much shorter than other Solanaceae. However, the molecular mechanisms involved are mostly unknown in these species. The present study examines the differences in seed longevity among Capsicum species and varietal types. Feral or less domesticated species, such as Capsicum chinense and particularly Capsicum frutescens, showed higher germination rates than the more domesticated Capsicum annuum after accelerated seed aging treatments. In addition, variability was detected in the expression of genes involved in the response to seed deterioration. The differences observed in ASPG1 expression led us to study the seed protein profile in dry and germinating seeds. Seed storage protein mobilization during germination was faster in seed aging-resistant genotypes. Similarly, the transcriptional change observed for the orthologous gene of the trans-species regulator AtHB25 prompted us to study the structure and molecular components of the seed coat in peppers. All the Capsicum pepper accessions analyzed presented very lignified testa and we observed a positive correlation between the amount of lignin and seed viability. Our results provide essential information to explain the poor germination observed in pepper seeds and provide an experimental framework for future improvements in this important character, The authors want to thank Marisol Gascon of the microscope service at the IBMCP. This work has been partially financed by the project PID2019-110221RR-C32, FEDER/ERDF funds.

Glucosinolates are sulfur compounds responsible at least in part of the the characteristic flavor of cruciferous vegetables and condiments. The glucosinolates [and their cognate bioactive forms, the isothiocyanates (ITCs) and indoles] have been studied for decades because of their antimicrobial, anticancer and antiinflammatory bioactivities Eating cruciferous foods is the direct and easiest way for the intake of glucosinolates; it also has the advantage of the coingestion of plant myrosinase enzymes that mediate the hydrolysis of glucosinolates into their bioactive metabolites: ITCs and indoles. However, industrial and cooking processing can negatively affect the stability of glucosinolates and myrosinases. This chapter reviews the effect that conventional processing has on the content of glucosinolates, commonly associated with losses due to thermal degradation. Alternatively, other innovative, nonthermal processing is reviewed as technologies for preserving these compounds and increasing their extractability. Finally, the established methodologies for the extraction and analysis of glucosinolates are discussed, including alternative protocols for assisting such a task.

Soil salinity is becoming one of the most critical problems for agriculture in the current climate change scenario. Growth parameters, such as plant height, root length and fresh weight, and several biochemical stress markers (chlorophylls, total flavonoids and proline), have been determined in young plants of Solanum melongena, its wild relative Solanum insanum, and their interspecific hybrid, grown in the presence of 200 and 400 mM of NaCl, and in adult plants in the long-term presence of 80 mM of NaCl, in order to assess their responses to salt stress. Cultivated eggplant showed a relatively high salt tolerance, compared to most common crops, primarily based on the control of ion transport and osmolyte biosynthesis. S. insanum exhibited some specific responses, such as the salt-induced increase in leaf K+ contents (653.8 μmol g−1 dry weight) compared to S. melongena (403 μmol g−1 dry weight) at 400 mM of NaCl. Although there were no substantial differences in growth in the presence of salt, biochemical evidence of a better response to salt stress of the wild relative was detected, such as a higher proline content. The hybrid showed higher tolerance than either of the parents with better growth parameters, such as plant height increment (7.3 cm) and fresh weight (240.4% root fresh weight and 113.3% shoot fresh weight) at intermediate levels of salt stress. For most biochemical variables, the hybrid showed an intermediate behaviour between the two parent species, but for proline it was closer to S. insanum (ca. 2200 μmol g−1 dry weight at 200 mM NaCl). These results show the possibility of developing new salt tolerance varieties in eggplant by introducing genes from S. insanum.

Peppers (Capsicum sp.) are used both as vegetables and/or spice and their fruits are used in a plethora of recipes, contributing to their flavor and aroma. Among flavor-related traits, pungency (capsaicinoids) and lately volatiles have been considered the most important factors. However, the knowledge of sugars is low, probably due to the fact peppers were historically considered tasteless. Here, using HPLC, we studied the content and profile of major sugars and capsaicinoids in a comprehensive collection of varietal types (genotype, G), grown under different growing systems (environment, E) in two years (Y) and considered the two main ripening stages (R). We found a major contribution to the ripening stage and the genotype in total and individual sugars and capsaicinoids. The year was also significant in most cases, as well as the G × E and G × Y interactions, while the growing system was low or nil. Ripening increased considerably in sugars (from 19.6 to 36.1 g kg−1 on average) and capsaicinoids (from 97 to 142 mg kg−1 on average), with remarkable differences among varieties. Moreover, sugars in fully ripe fruits ranged between 7.5 and 38.5 g kg−1 in glucose and between 5.2 and 34.3 g kg−1 in fructose, and several accessions reached total sugars between 40 and 70 g kg−1, similar to tomatoes. The results reveal the importance of the genotype and the ripening for these traits, particularly sugars, which should be considered key for the improvement of taste and flavor in peppers.

Antiviral treatments inhibiting Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication may represent a strategy complementary to vaccination to fight the ongoing Coronavirus disease 19 (COVID-19) pandemic. Molecules or extracts inhibiting the SARS-CoV-2 chymotripsin-like protease (3CLPro) could contribute to reducing or suppressing SARS-CoV-2 replication. Using a targeted approach, we identified 17 plant products that are included in current and traditional cuisines as promising inhibitors of SARS-CoV-2 3CLPro activity. Methanolic extracts were evaluated in vitro for inhibition of SARS-CoV-2 3CLPro activity using a quenched fluorescence resonance energy transfer (FRET) assay. Extracts from turmeric (Curcuma longa) rhizomes, mustard (Brassica nigra) seeds, and wall rocket (Diplotaxis erucoides subsp. erucoides) at 500 µg mL−1 displayed significant inhibition of the 3CLPro activity, resulting in residual protease activities of 0.0%, 9.4%, and 14.9%, respectively. Using different extract concentrations, an IC50 value of 15.74 µg mL−1 was calculated for turmeric extract. Commercial curcumin inhibited the 3CLPro activity, but did not fully account for the inhibitory effect of turmeric rhizomes extracts, suggesting that other components of the turmeric extract must also play a main role in inhibiting the 3CLPro activity. Sinigrin, a major glucosinolate present in mustard seeds and wall rocket, did not have relevant 3CLPro inhibitory activity; however, its hydrolysis product allyl isothiocyanate had an IC50 value of 41.43 µg mL−1. The current study identifies plant extracts and molecules that can be of interest in the search for treatments against COVID-19, acting as a basis for future chemical, in vivo, and clinical trials.

Antiviral treatments inhibiting Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication may represent a strategy complementary to vaccination to fight the ongoing Coronavirus disease 19 (COVID-19) pandemic. Molecules or extracts inhibiting the SARS-CoV-2 chymotripsin-like protease (3CLPro) could contribute to reducing or suppressing SARS-CoV-2 replication. Using a targeted approach, we identified 17 plant products that are included in current and traditional cuisines as promising inhibitors of SARS-CoV-2 3CLPro activity. Methanolic extracts were evaluated in vitro for inhibition of SARS-CoV-2 3CLPro activity using a quenched fluorescence resonance energy transfer (FRET) assay. Extracts from turmeric (Curcuma longa) rhizomes, mustard (Brassica nigra) seeds, and wall rocket (Diplotaxis erucoides subsp. erucoides) at 500 µg mL−1 displayed significant inhibition of the 3CLPro activity, resulting in residual protease activities of 0.0%, 9.4%, and 14.9%, respectively. Using different extract concentrations, an IC50 value of 15.74 µg mL−1 was calculated for turmeric extract. Commercial curcumin inhibited the 3CLPro activity, but did not fully account for the inhibitory effect of turmeric rhizomes extracts, suggesting that other components of the turmeric extract must also play a main role in inhibiting the 3CLPro activity. Sinigrin, a major glucosinolate present in mustard seeds and wall rocket, did not have relevant 3CLPro inhibitory activity; however, its hydrolysis product allyl isothiocyanate had an IC50 value of 41.43 µg mL−1. The current study identifies plant extracts and molecules that can be of interest in the search for treatments against COVID-19, acting as a basis for future chemical, in vivo, and clinical trials.

[EN] Spain is a relevant secondary centre of diversity for Capsicum annuum peppers, especially for the bell types known as Pimiento Morron or Pimiento de Morro. Thus, a myriad of highly regarded landraces adapted to a wide range of conditions can be found throughout the country, as a result of centuries of farmers breeding. Despite that, these materials lack of proper characterization, of paramount importance for farmers, breeders and germplasm management. In this regard, in addition to internationally accepted conventional descriptors, high-throughput digital phenotyping tools like Tomato Analyzer, a software originally developed to process scanned images of cut tomato fruits and to record a range of morphological parameters, may provide an important help towards exhaustive germplasm characterization. With this aim, 32 conventional and 35 Tomato Analyzer digital traits were used herein to characterize a large collection of C. annuum accessions from all Spanish regions, including Protected Designations of Origin and Protected Geographical Indications, with emphasis on Marron peppers, in order to assess the diversity within Spanish elite germplasm and to test the efficiency of those methods to differentiate varietal types and closely related materials. A considerable amount of variation was found using both conventional and digital traits, even within Marron pepper groups, reflecting the diversity of Spanish peppers in terms of plant and fruit morphology, essential for future breeding programs. Both conventional descriptors and digital parameters were able to distinguish varietal groups. However, on the whole, digital phenotyping was able to discriminate in a more accurate way. Most digital parameters were able to discriminate varietal groups into higher numbers of categories (>= 4) than conventional traits (usually 2-4). In addition, the number of significant pairwise differences among varietal groups was considerably higher for digital parameters than for conventional descriptors, enabling a powerful separation, particularly relevant for closely related groups such as Morron peppers. Likewise, as revealed by Principal Components Analysis, digital phenotyping allowed a more powerful intra-varietal separation compared to conventional descriptors. Finally, a subset of 4 conventional descriptors and 13 Tomato Analyzer traits were identified as the most discriminant to distinguish among closely related C. annuum accessions, explaining 81.81 % of total variance found by Principal Components Analysis. Fruit traits explained the highest percentage of variance for our collection, This work has been financed by INIA projects RTA2014-00041-C02-02 and RF2010-00025-00-00, FEDER fund\s. Authors are also grateful to the different Research Institutions, scientists and breeders, and PDOs and PGIs Regulatory Boards, included on Table 1 for providing part of the materials studied here. Finally, thanks are given to Prof. Jaime Prohens for his kind and useful advice in the statistic interpretation of PCAs and MSc Elena Rosa for her help in the edition of Fig. 1.

[EN] Peppers, a worldwide crop, are threatened by different pathogens. Powdery mildew, a biotroph fungal infection, can cause several damages directly on vegetative parts and indirectly on fruits. Despite some sources of resistance have been described, commercial genotypes only with partial resistance have been developed due to the complex nature of such resistance and variable genetic expression, which depends on the stage of the plants. In this paper 49 accessions from different Capsicum species and origins have been tested. Plants were grown in growth chambers inside of mini greenhouses. Repeated inoculations under pepper leaves were applied by spraying a suspension of 104 conidia ml-1. Readings were made at 30 and 60 days after inoculation (DAI). Total number of leaves (TL), total number of affected leaves (LA), and maximum area affected (MAA) in the most damaged leaf were scored. In addition, a composite infection index (CII) was calculated on the basis of the three mentioned traits. Inoculated plants showed more severe symptoms at 30 DAI than at 60 DAI. Different response patterns were observed: from accessions suffering high leaf shedding to some others with local hypersensitive response, indicating different gene action. The use of CII prevented species bias and disease response. In the present work, four highly tolerant accessions were identified, including two chiltepins, C. annuum wild relatives, Ag-01 and Ag-02, and two C. annuum A-06 and A-23., IIMM acknowledges his work was supported by CONACYT-CONCYTEP predoctoral scholarship number 47274 by the Mexican government. This work has been partially financed by the projects RTA2014-00041-C02-02 y PID2019110221RRC32, from Spain's Plan Nacional, INIA and FEDER/ERDF funds.

[EN] This study investigated the physiological and biochemical responses to salinity stress of Solanum melongena and its wild relative, Solanum torvum, commonly used as eggplant rootstock. Young plants of both species were watered during 25 days with NaCl aqueous solutions at the following four final concentrations: 0 (for the controls), 100, 200, and 300 mM. Plant growth parameters, photosynthetic pigments content, monovalent ion concentrations in roots and leaves, leaf levels of osmolytes (proline and total soluble sugars), oxidative stress markers (MDA and H2O2), non-enzymatic antioxidants (total phenolic compounds and total flavonoids), and enzymatic antioxidant activities superoxide dismutase, catalase, glutathione reductase) were determined after the stress treatments. Salt-induced growth reduction was more significant in S. melongena than in S. torvum, especially at high salt concentrations, indicating a (slightly) higher salt tolerance of the wild species. The mechanisms of tolerance of S. torvum were partly based on the active transport of toxic ions to the leaves at high external salinity and, presumably, a better capacity to store them in the vacuoles, as well as on the accumulation of proline to higher concentrations than in the cultivated eggplant. MDA and H2O2 contents did not vary in response to the salt treatments in S. torvum. However, in S. melongena, MDA content increased by 78% when 300 mM NaCl was applied. No activation of antioxidant mechanisms, accumulation of antioxidant compounds, or increase in the specific activity of antioxidant enzymes in any of the studied species was induced by salinity. The relatively high salt tolerance of S. torvum supports its use as rootstock for eggplant cultivation in salinized soils and as a possible source of salt-tolerance genes for the genetic improvement of cultivated eggplant.This study investigated the physiological and biochemical responses to salinity stress of Solanum melongena and its wild relative, Solanum torvum, commonly used as eggplant rootstock. Young plants of both species were watered during 25 days with NaCl aqueous solutions at the following four final concentrations: 0 (for the controls), 100, 200, and 300 mM. Plant growth parameters, photosynthetic pigments content, monovalent ion concentrations in roots and leaves, leaf levels of osmolytes (proline and total soluble sugars), oxidative stress markers (MDA and H2O2), non-enzymatic antioxidants (total phenolic compounds and total flavonoids), and enzymatic antioxidant activities (superoxide dismutase, catalase, glutathione reductase) were determined after the stress treatments. Salt-induced growth reduction was more significant in S. melongena than in S. torvum, especially at high salt concentrations, indicating a (slightly) higher salt tolerance of the wild species. The mechanisms of tolerance of S. torvum were partly based on the active transport of toxic ions to the leaves at high external salinity and, presumably, a better capacity to store them in the vacuoles, as well as on the accumulation of proline to higher concentrations than in the cultivated eggplant. MDA and H2O2 contents did not vary in response to the salt treatments in S. torvum. However, in S. melongena, MDA content increased by 78% when 300 mM NaCl was applied. No activation of antioxidant mechanisms, accumulation of antioxidant compounds, or increase in the specific activity of antioxidant enzymes in any of the studied species was induced by salinity. The relatively high salt tolerance of S. torvum supports its use as rootstock for eggplant cultivation in salinized soils and as a possible source of salt-tolerance genes for the genetic improvement of cultivated eggplant., This work was undertaken as part of the initiative "Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing CropWild Relatives" which is supported by the Government of Norway and managed by the Global Crop Diversity Trust. For further information, see the project website: http://cwrdiversity.org/.Funding was also received from Ministerio de Ciencia, Innovacion y Universidades, Agencia Estatal de Investigacion and Fondo Europeo de Desarrollo Regional (grant RTI-2018-094592-B-100 from MCIU/AEI/FEDER, UE), European Union's Horizon 2020 Research and Innovation Programme under grant agreement No. 677379 (Linking genetic resources, genomes and phenotypes of Solanaceous crops; G2P-SOL) and Vicerrectorado de Investigacion, Innovacion y Transferencia de la Universitat Politecnica de Valencia (Ayuda a Primeros Proyectos de Investigacion; PAID-06-18). Mariola Plazas is grateful to Generalitat Valenciana and Fondo Social Europeo for a post-doctoral grant (APOSTD/2018/014). Marco Brenes is indebted to the Faculty of Biology of the Costa Rica Institute of Technology for partially supporting his stay in Valencia ("Fondo Solidario y Desarrollo Estudiantil").

[EN] Wall rocket is a leafy vegetable with pungent flavor related to the presence of isothiocyanates (ITCs). Despite interest in it as a crop of high organoleptic quality, the variability of the volatile profile in the species remains unknown. Twenty-four populations grown under a greenhouse were evaluated. A considerable diversity for the total levels of volatiles was found, providing information of the aroma intensity among accessions. ITCs represented the main fraction. Allyl ITC was the main compound, and levels showed up to 6-fold difference among populations. The esters fraction was mainly represented bycis-3-hexenyl isovalerate andcis-3-hexenyl butyrate, with 20-fold differences among populations. Additionally, the content in sinigrin was evaluated as main GSL in wall rocket. Differences reached up to 13-fold. These results suggest that some populations can be used to develop highly pungent varieties, whereas some others can be selected for mild-pungent varieties, as it is the case of DER045 with low levels of ITCs and high in esters. The presence of several ITCs in the profile also suggested the presence of other novel GSLs. Overall, the work increases the knowledge in the variability of wall rocket for the volatile profile and sinigrin accumulation, a starting point for future breeding programs., C.G. thanks the Ministerio de Educacion, Cultura y Deporte of Spain (MECD) for the financial support by means of a predoctoral FPU grant (FPU14-06798).

Capsicum peppers (Capsicum spp.), especially C. annuum L., are one of the most important vegetables and spices in the world and their fruits are used in a range of food dishes, to provide aroma and flavor. Pungency has been largely studied, while studies on the volatile fraction are more recent and less diverse. A considerable varietal diversity among peppers has been reported in terms of the aroma quality and the qualitative and quantitative variation in the volatile fraction, particularly in fully ripe fruits, which encompass most diverse food applications and aroma profiles. Thus, a study was designed to study the inheritance of the volatile fractions in peppers and to determine if they can be improved by breeding strategies. The volatile fraction of 175 samples of ripe fruits from a diverse collection of peppers, encompassing a range of varietal types and aroma qualities, were isolated by headspace-solid-phase microextraction (HS-SPME) and analyzed by gas chromatography&ndash, mass spectrometry (GC&ndash, MS). A diverse profile of volatiles including terpenoids, esters, alkanes, and several aldehydes and alcohols, was found among the evaluated accessions. Our findings indicated that, in most cases, hybridization provided higher amounts of total volatiles and a more complex composition, particularly in the pericarp. In addition, the volatile fraction can be inherited from the parents to the offspring, as most individual volatiles in hybrids, especially major volatiles, were present in at least one of the parents, following intermediate (levels between parents) or transgressive (levels higher than the best parent) inheritance. De novo compounds (present in the hybrid, absent in the parents) were found in many samples. Comparatively, placental tissues had higher total and individual volatile levels compared with the pericarp in most parent accessions and hybrids, which must be considered by breeders if this part of the fruit is included in food formulations. By combining parent lines with complementary volatile fractions, hybridization offers a feasible method to improve the volatile composition of ripe fruits in Capsicum peppers.

Agriculture will face many challenges regarding food security and sustainability. Improving phosphorus use efficiency is of paramount importance to face the needs of a growing population while decreasing the toll on the environment. Pepper (Capsicum spp.) is widely cultivated around the world, hence, any breakthrough in this field would have a major impact in agricultural systems. Herein, the response to phosphorus low-input conditions is reported for 25 pepper accessions regarding phosphorus use efficiency, biomass and root traits. Results suggest a differential response from different plant organs to phosphorus starvation. Roots presented the lowest phosphorus levels, possibly due to mobilizations towards above-ground organs. Accessions showed a wide range of variability regarding efficiency parameters, offering the possibility of selecting materials for different inputs. Accessions bol_144 and fra_DLL showed an interesting phosphorus efficiency ratio under low-input conditions, whereas mex_scm and sp_piq showed high phosphorus uptake efficiency and mex_pas and sp_bola the highest values for phosphorus use efficiency. Phosphorus low-input conditions favored root instead of aerial growth, enabling increases of root total length, proportion of root length dedicated to fine roots and root specific length while decreasing roots&rsquo, average diameter. Positive correlation was found between fine roots and phosphorus efficiency parameters, reinforcing the importance of this adaptation to biomass yield under low-input conditions. This work provides relevant first insights into pepper&rsquo, s response to phosphorus low-input conditions.

Eggplant (Solanum melongena) has been described as moderately sensitive to salinity. We characterised the responses to salt stress of eggplant and S. insanum, its putative wild ancestor. Young plants of two accessions of both species were watered for 25 days with an irrigation solution containing NaCl at concentrations of 0 (control), 50, 100, 200, and 300 mM. Plant growth, photosynthetic activity, concentrations of photosynthetic pigments, K+, Na+, and Cl&minus, ions, proline, total soluble sugars, malondialdehyde, total phenolics, and total flavonoids, as well as superoxide dismutase, catalase, and glutathione reductase specific activities, were quantified. Salt stress-induced reduction of growth was greater in S. melongena than in S. insanum. The photosynthetic activity decreased in both species, except for substomatal CO2 concentration (Ci) in S. insanum, although the photosynthetic pigments were not degraded in the presence of NaCl. The levels of Na+ and Cl&minus, increased in roots and leaves with increasing NaCl doses, but leaf K+ concentrations were maintained, indicating a relative stress tolerance in the two accessions, which also did not seem to suffer a remarkable degree of salt-induced oxidative stress. Our results suggest that the higher salt tolerance of S. insanum mostly lies in its ability to accumulate higher concentrations of proline and, to a lesser extent, Na+ and Cl&minus, The results obtained indicate that S. insanum is a good candidate for improving salt tolerance in eggplant through breeding and introgression programmes.

[EN] Cultivated rocket (Eruca vesicaria) is a leafy vegetable highly appreciated for its healthpromoting virtues and consumed both raw and cooked as ready-to-use vegetable. Despite Eruca being cultivated worldwide, only a few cultivars are available and limited breeding activities have been carried out so far. Therefore, the genetic resources available represent an unexploited potential source of variation for breeding. In the present study, 155 E. vesicaria accessions from 30 countries across Europe, Asia, Africa, and America have been characterized for 54 qualitative and quantitative morphological and quality traits. Conventional descriptors and automated tools for the determination of the quality, morphology, and colour of leaves have been used. Genetic diversity was assessed using 15 inter simple sequence repeat and simple sequence repeat markers. A high level of diversity was evidenced in the collection. Significant differences were found in most of the traits with the exception of five pseudo-qualitative descriptors. The first and second dimensions of the principal components analysis with phenotypic traits accounted for 25.69% of total variation showing a stratification of the genotypes according to the European and Asian origins. In total, 75% of the variation was contained in the first 15 components having eigenvalues higher than 1.0. Also, the population structure divided the collection into two main clusters separating European genotypes from the rest. Furthermore, hierarchical cluster analysis confirmed a geographical separation, grouping the accessions into three major clusters, which were differentiated by plant architecture, leaf and flower colour, leaf water status, leaf blade shape and hairiness of the leaves and stem. Our approach has broadened the knowledge of the diversity within the Eruca gene pool, thus contributing to identify sources of variation and to select the best candidates for cultivated rocket breeding programs, as well as to determine the genetic basis of plant and leaf traits in future genome-wide association studies., The work was supported by 'RGV-FAO' project funded by the Italian Ministry of Agriculture, Food and Forestry. C. Guijarro-Real thanks the Ministerio de Educacion, Cultura y Deporte of Spain (MECD) for its financial support by means of a predoctoral FPU Grant (FPU14/06798), and for the specific grant for mobility (EST17/00354) from the same Organization.

[EN] Wall rocket (Diplotaxis erucoides) is a wild vegetable with potential as a crop. Its seeds present secondary dormancy mechanisms that can become essential for the survival of wall rocket as a weed or in the wild. However, adaptation to crop conditions requires high and synchronised germination. The present work was aimed at studying whether different treatments improve the germination success of wall rocket seeds, and the effects on subsequent crop quality (morphology, yield, ascorbic acid and phenolics). By using of a L8 orthogonal array design, the main effects of soaking the seeds, scarification with sodium hypochlorite (NaClO), gibberellic acid (GA3), potassium nitrate (KNO3), cold, and heat treatments on germination traits of wall rocket were evaluated. NaClO scarification was the most efficient treatment and significantly increased the early and final germination, the germination rate and the vigour index. The best germination results were obtained when the NaClO scarification was followed by application of GA3. Thus, a protocol consisting on scarification with 2.5% NaClO for 5 min followed by treatment with 150 ppm GA3 for 24 h was proposed to improve wall rocket germination success. In addition, the germination treatments did not greatly affect the agronomic characters of baby-leaf plants. Scarification with NaClO reduced the days to harvest but did not affect the yield, so its use could have commercial benefits. Moreover, the content in ascorbic acid increased in treatments using NaClO, which may increase the added value of the potential crop. Overall, this study contributes to the domestication of wall rocket by providing a simple germination method that in addition has potential beneficial effects for crop quality., C. Guijarro-Real thanks the Ministerio de Educacion, Cultura y Deporte (MECD) of Spain for financial support by means of a predoctoral grant (FPU14-06798). The research did not receive any other specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Abiotic stress represents a main constraint for agriculture, affecting plant growth and productivity. Drought and soil salinity, especially, are major causes of reduction of crop yields and food production worldwide. It is not unexpected, therefore, that the study of plant responses to abiotic stress and stress tolerance mechanisms is one of the most active research fields in plant biology. This Special Issue compiles 22 research papers and 4 reviews covering different aspects of these responses and mechanisms, addressing environmental stress factors such as drought, salinity, flooding, heat and cold stress, deficiency or toxicity of compounds in the soil (e.g., macro and micronutrients), and combination of different stresses. The approaches used are also diverse, including, among others, the analysis of agronomic traits based on morphological characteristics, physiological and biochemical studies, and transcriptomics or transgenics. Despite its complexity, we believe that this Special Issue provides a useful overview of the topic, including basic information on the mechanisms of abiotic stress tolerance as well as practical aspects such as the alleviation of the deleterious effects of stress by different means, or the use of local landraces as a source of genetic material adapted to combined stresses. This knowledge should help to develop the agriculture of the (near) future, sustainable and better adapted to the conditions ahead, in a scenario of global warming and environmental pollution.

[EN] BACKGROUND In recent years, the acreage used for organic agriculture and the demand for organic fruit and vegetables have increased considerably. Given this scenario, landraces, such as Capsicum landraces, can provide valuable germplasm. Capsicum peppers are very interesting because of their high phenolic content, and particularly their flavonoid content, which provides a high added value. Moreover, the broad genetic diversity in local varieties expands the opportunities for adaptation to organic production and for exploiting genotype x environment interactions to select peppers with the highest phenolic content. RESULTS In this work, the main flavonoids of peppers were exhaustively evaluated over 2 years in a wide collection of heirlooms, both unripe and fully ripe, under organic and conventional cultivation. The genotype and ripening stage contributed to a high degree to the variation in flavonoids. The growing system influenced this variation to a lesser extent. Luteolin and quercetin showed the highest contributions to total phenolic content (70% and > 20%, respectively) at both ripening stages, while myricetin, apigenin, and kaempferol showed lower contributrions. The average flavonoid content was higher in ripe fruits, and organic management significantly increased the accumulation of total flavonoids and luteolin. Positive correlations between flavonoids were found at both ripening stages, especially between main flavonoids luteolin and quercetin and between kaempferol and quercetin (rho > 0.7). CONCLUSION Genotype x environment interaction enabled the identification of accessions with high flavonoid content grown under organic conditions at both ripening stages, particularly total flavonoids and luteolin at the fully ripe stage. Our results reinforce the importance of a wide genetic variation and of considering different ripening stages and growing conditions for breeding high-quality peppers., This work has been funded by the Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA) project RTA2014-00041-C02-02, Fondo Europeo de Desarrollo Regional (FEDER) funds. A.M. Ribes-Moya expresses her gratitude to the Universitat Politecnica de Valencia (UPV) for her scholarship FPI-UPV-2017 (PAID-01-17). The authors also thank the farmers' association Unio de Llauradors i Ramaders (LA UNI) for the arrangement and management of fields - specifically Manuel Figueroa, Rafael Hurtado, Ricard Ballester, and Antonio Munoz, and seed providers P.W. Bosland, S. Lanteri, Francois Jourdan, Santiago Larregla, and the Regulatory Boards of the PDOs and PGIs included in this work. The authors are also grateful for the support of Professor Jaime Prohens with statistical methods.

Wild relatives of eggplant (Solanum melongena) are of interest for breeding for tolerance to drought. To assess the potential of eggplant wild relatives from different gene pools, 18 accessions belonging to eggplant and eight wild relatives were evaluated for water stress tolerance. Plants grown in pots were normally irrigated or subjected to water stress by stopping irrigation. Growth and biochemical parameters related to oxidative stress, including proline, malondialdehyde (MDA), total phenolics and total flavonoids contents, and catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione reductase (GR) activities, were determined after 11 days of treatment. The reduction of dry matter content in the aerial part of the water-stressed vs. control plants allowed classifying the accessions into three groups: tolerant ( 35% reduction). Proline concentration increased in all accessions under water stress, in particular in the more tolerant ones, which showed an average increase of more than 30-fold over control values, compared to ca. 8-fold in the susceptible accessions. The group of tolerant accessions, which included S. incanum, S. pyracanthos, S. dasyphyllum and S. torvum, was also characterised by unchanged MDA contents and a more pronounced increase in the mean levels of flavonoids (20.6% over the non-stressed controls vs. 3.4% in the intermediate accessions and 5.0% in the least tolerant ones). The activity of antioxidant enzymes was extremely variable within groups and even within the same species. The results obtained reveal a high diversity for drought tolerance in the wild relatives of eggplant and provide insights into the biochemical mechanisms involved in the response to drought in eggplant wild relatives. The tolerant materials identified are of interest for breeding programmes for developing rootstocks and new eggplant cultivars with higher drought tolerance.

Lophophora williamsii is an ornamental slow growth cactus highly appreciated by cacti growers and hobbyists. Its demand is often satisfied through illegal collection of wild plants and many populations are threatened with extinction. Thus, an efficient in vitro protocol without plant growth regulators will be of great interest for conservation purposes of this cactus. Eight different germination media, combining Murashige and Skoog medium (MS, full and half-strength), sucrose (20 and 30 g L−1) and agar (8 and 10 g L−1), were used to study germination rate, number of seedlings with areoles and initial seedling development. Germination rates among culture media only differed significantly in the first 14 days after sowing (DAS), reaching 67–75% at the end of the assay (49 DAS). Remarkable interactions among media components were detected, and 20 g L−1 sucrose and 8 g L−1 agar combination gave the highest performance for both size and number of areoles. Following germination assay, a growth assay was conducted during 105 days using three growth media (GrM) at different sucrose concentration (15, 30 and 45 g L−1) to evaluate the increase in seedling size and number of areoles. Regardless of their initial size, 15 g L−1 sucrose provided the best results for both traits. Size increase was higher in the 4–5 mm seedling group, while increase in areoles was greater in 2-3 mm seedlings. It was possible to develop an in vitro protocol, in absence of plant growth regulators, which allows maximizing L. williamsii germination and growth during its first stages of development, which may increase the availability of plants in the market and avoid exhaustion of wild populations. Furthermore, plants grown ex situ could be reintroduced in endangered natural populations.

[EN] Chile peppers are one of the most important crops in Mexico and a plethora of ecotypes can be found there. Most of them are ancient open-pollinated (OP) landraces selected by farmers for uniform phenotype but with an inherent level of genetic diversity, called criollos. In this work 15 pepper accessions, encompassing 2 criollo lines, their open-pollinated progenies, and 5 controls, were characterized with a set of 36 IPGRI descriptors and 23 SSR markers to assess the effect of open pollination in the inbreeding process. Heterozygosity levels were comprised between 12 and 47% in the progenies, which were similar or lower than those values from parent plants and similar or higher than control cultivars. Also, both progenies and parents showed similar levels of agronomic and morphological uniformity. Our results suggest that this OP program is efficient in terms of reaching enough agronomic uniformity in criollo Ancho peppers while preserving certain genetic diversity to confer adaptation to climate change., This work was partly financed by projects INIA RTA2013-00022-C02-02 and RTA2014-00041-C02-02, funded by Instituto Nacional Investigaciones Agrarias (Spain), FEDER funds. Also, Mexican authors thank CONACYT for financing the stay of Gustavo Chavez-Gonzalez in Spain, as well as the Programa Integral de Fortalecimiento Institucional (PIFI) de la UA de Aguascalientes (SEP-Mexico).

Grafting technique is increasing thanks to its potential to produce plants more efficient and tolerant to biotic and abiotic stresses. Likewise, there is a growing interest in reducing inputs of fertilizers. The development of rootstocks suitable for low input agriculture is conditioned to the understanding of the changes on the root when facing such stresses. Our aim was to evaluate the morphological root response to Phosphorus (P) starvation of a rootstock selected for its good performance under low P conditions. Adige was grafted onto the selected rootstock and grown hydroponically in two different P concentrations, the selft-graft was done as control. Plants were then collected and analysed. Results showed that despite the differences in terms of P concentration among treatment the stress was not enough to cause a great biomass loss. However, there is evidence that individuals showed different root adaptations, modifiying root length, mass and volume, etc, under stress conditions, having the selected rootstock higher root length and volume under low P nutrient solution

[EN] Wall rocket (Diplotaxis erucoides) is a wild vegetable with the potential to become a crop of high antioxidant quality. The main bioactive compounds include ascorbic acid (AA), sinigrin, and a high content of total phenolic compounds (TP). It also accumulates nitrates. Since these compounds are affected by environmental conditions, adequate crop management may enhance its quality. Eleven accessions of wall rocket were evaluated under field and greenhouse conditions during two cycles (winter and spring) and compared to Eruca sativa and Diplotaxis tenuifolia crops. The three species did not differ greatly. As an exception, sinigrin was only identified in wall rocket. For the within-species analysis, the results revealed a high effect of the growing system, but this was low among accessions. The highest contents of AA and TP were obtained under field conditions. In addition, the levels of nitrates were lower in this system. A negative correlation between nitrates and antioxidants was determined. As a counterpart, cultivation in the field¿winter environment significantly decreased the percentage of humidity (87%). These results are of relevance for the adaptation of wall rocket to different growing conditions and suggest that the field system enhances its quality. The low genotypic differences suggest that intra-species selections in breeding programs may consider other aspects with greater variation., C.G. is grateful to the Ministerio de Educacion, Cultura y Deporte of Spain (MECD) for the financial support by means of a predoctoral FPU grant (FPU14-06798). The authors also thank Ms. E. Moreno and Ms. M.D. Lerma for their help in the field tasks.

[EN] Water celery (Apium nodiflorum) is a wild plant traditionally harvested in some Mediterranean areas for being consumed raw. Despite its appreciated organoleptic properties, the aromatic profile of the fresh vegetable remains to be studied. In the present study, volatile compounds from five wild populations were extracted by the headspace-solid phase microextraction technique, analysed by gas cromatography-mass spectrometry, and compared to related crops. The wild species had a high number of aromatic compounds. It was rich in monoterpenes (49.2%), sesquiterpenes (39.4%) and phenylpropanoids (9.6%), with quantitative differences among populations, in absolute terms and relative abundance. On average, germacrene D was the main compound (16.6%), followed by allo-ocimene (11.9%) and limonene (11.1%). Only in one population, the levels of limonene were greater than those of germacrene D. Among phenylpropanoids, dillapiol displayed the highest levels, and co-occurred with myristicin in all populations except one. These differences may have a genetic component, which would indicate the possibility of establishing selection programmes for the development of water celery as a crop adapted to different market preferences. On the other hand, comparison with related crops revealed some similarities among individual volatiles present in the different crops, which would be responsible of the common aroma notes. However, water celery displayed a unique profile, which was in addition quantitatively richer than others. Thus, this differentiation may promote the use of water celery as a new crop., C. Guijarro-Real thanks the Ministerio de Educacion, Cultura y Deporte of Spain (MECD) for the financial support with a predoctoral FPU grant (FPU14-06798). Authors also thank Manuel Figueroa for his unvaluable ethnobotanical knowledge and advice, as well as his support in the survey of water celery in the Horta Nord shire

[EN] Little information is available on the physiological and biochemical responses to water stress in eggplant (Solanum melongena). We valuated four genetically diverse eggplant varieties (MEL3-MEL6) under control and water stress conditions. Measurements were taken for plant growth, tissue water content, levels of chlorophylls a and b, carotenoids, roline, malondialdehyde, total phenolics, total flavonoids, superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase APX), and glutathione reductase (GR) activities. For most traits, the water stress treatment had a greater contribution than the variety effect to the total sums of squares in an ANOVA analysis, except for total flavonoids, SOD, APX, and GR. The water stress treatment had a strong effect on plant growth and tissue water content. In general, water tress reduced the three photosynthetic pigments, increased proline, malondialdehyde, total phenolics, and total flavonoids, although some varietal differences were ob- served. Different patterns were also detected in the activities of the four enzymes evaluated, but few differences were observed for individual varieties between the control and water stress treatments. Many significant phe- notypic orrelations were observed among the traits studied, but only eight environmental correlations were detected. A PCA analysis distinctly separated individuals according to the treatment, and revealed a clearer separation of varieties under water stress than under control conditions, pointing to varietal differences in the responses to stress. Our results suggest that proline could be used as a marker for drought stress tolerance in this species. The information obtained provides new insight on the physiological and biochemical responses of eggplant to drought stress, Authors are grateful to the European Union's Horizon 2020 Research and Innovation Programme under grant agreement No 677379 (G2P-SOL project: Linking genetic resources, genomes and phenotypes of Solanaceous crops), to Ministerio de Economfa, Industria y Competitividad and Fondo Europeo de Desarrollo Regional (grant AGL2015-64755-R from MINECO/FEDER), to Ministerio de Ciencia, Innovation y Universidades, Agencia Estatal de Investigation and Fondo Europeo de Desarrollo Regional (grant RTI-2018-094592-B-100 from MCIU/AEI/FEDER, UE), to the Generalitat Valenciana and Fondo Social Europeo (Ayuda a Grupos Emergentes; GV/2019/033), to the Vicerrectorado de Investigacien, Innovation y Transferencia de la Universitat Politecnica de Valencia (Ayuda a Primeros Proyectos de Investigation; PAID-06-18), and to the initiative "Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives", which is supported by the Government of Norway. This latter project is managed by the Global Crop Diversity Trust with the Millennium Seed Bank of the Royal Botanic Gardens, Kew and implemented in partnership with national and international gene banks and plant breeding institutes around the world. For further information see the project website: http://www.cwrdiversity.org/. Mariola Plazas is grateful to Generalitat Valenciana and Fondo Social Europeo for a post-doctoral contract (APOSTD/2018/014). The contribution of Huu Trong Nguyen to this paper has been developed as a result of a mobility stay funded by Erasmus + KA1 Erasmus Mundus Joint Master Degrees Programme of the European Commission under the PLANT HEALTH project.

[EN] According to the new market trends, one of the goals in many modern breeding programmes is the development of varieties with enhanced bioactive properties. Despite the importance of evaluating the content of specific molecules, the analysis of the broad antioxidant capacity is often suitable. For instance, if the goal is to evaluate large quantity of materials, or even to compare different agronomical practices to obtain the highest antioxidant properties. Thus, studies related to plant breeding should include subjects related to the knowledge of analytical methods for the evaluation of the bioactive properties in the materials tested. Theoretical lessons establish the basis for understanding the importance of bioactive properties and the influence of stresses in their content. Nevertheless, practical sessions complement this knowledge and improve the competence of future professionals, providing them a tool for the evaluation of bioactive quality in developing breeding materials. We consider therefore that this competence should be acquired during the Master degree in Plant Breeding offered by our institute. Thus, we propose to introduce a practical lesson in the mandatory subject "Instrumental Techniques" aimed to the comparison of two analytical methods for the analysis of bioactive properties. As plant material, we will use water celery, an herbaceous species with great antioxidant properties. The methodology will include the analysis of the antioxidant activity with the DPPH method and the content in total phenolics, both spectrophotometric methods but measuring different aspects of the bioactive quality. The lesson is divided in three sessions of three hours each, in the course of which students will perform all steps for these analyses, including sample preparation, extraction of bioactive molecules, preparation of the calibration curve, and analysis of results. This practical lesson provides students with the competence to evaluate the antioxidant activity of high number of materials using quick and simple spectrophotometric methodologies, and to deal with real problems such as the need of dilution for samples with very high content of bioactive molecules. Moreover, the practical lesson provides the guidelines to adapt the protocols for different materials and consequently to many breeding programmes, and can be also adapted for food technology students., Carla Guijarro-Real is grateful to the Ministerio de Educación, Cultura y Deporte of Spain (MECD) for a predoctoral FPU grant (FPU14-06798). Mariola Plazas is grateful to Generalitat Valenciana and Fondo Social Europeo for a post-doctoral grant (APOSTD/2018/014). Pietro Gramazio is grateful to Universitat Politècnica de València for a post-doctoral contract (PAID-10-18) within the Programa de Ayudas de Investigación y Desarrollo initiative. Ana M Adalid-Martínez is grateful to the Ministerio de Ciencia, Innovación y Universidad of Spain for its support with a post-doctoral contract (PTA2015- 11502-I) within the Subprograma Personal Técnico de Apoyo initiative.

[EN] An essential step in many plant breeding programmes is the morphoagronomic phenotyping of the materials that are being developed, using standardized descriptors or, when not available, as it is the case of new crops, consensus guidelines to characterize them. Although many of the traits must be evaluated in the field, those related to the shape and size of leaves and fruits can be easily measured with specific software using digital pictures. This tool provides several advantages, including: 1) more accurate and objective measurements; 2) the possibility of measuring other traits of interest such as area or perimeter, that in other case would not be easily evaluated; or even 3) the possibility of delaying the analysis of pictures in order to focus on field traits. Therefore, the knowledge and management of this tool can become of high usefulness. The Plant Breeding Master offered by our institute is aimed at training professionals able to improve crops and develop new ones according to market trends, in addition to improve adaptation and resistance to biotic and abiotic stresses. Due to the importance of phenotyping considering any of the above breeding goals, in this paper we propose the introduction of a practical session in the mandatory subject "Instrumental Techniques": the management and comparison of adequacy of two specific software tools considering the material to be analyzed. As material, we propose a collection of pepper varieties for analysis of fruits, and a collection of rocket (Eruca and Diplotaxis spp.) germplasm for analysis of leaves, due to the broad variability observed in those materials. The MorphoLeaf v1.0 software will be used for the analysis of leaves, and the Tomato Analyzer 3.0 software will be used for the analysis of fruits and also for leaves. According to the design of the practical lesson, only one session of three hours is required, in which students will learn to properly digitalize materials considering the restrictions of each software and material used, and to obtain all the information needed in each case. In addition, there will be one hour of autonomous work in which both tools and the results obtained will be compared by the students, and a report will be prepared. This practical lesson allows students to acquire the competence for the correct use of different computer tools in the phenotyping task. The comparison of analyses using different scan adjustments and software will allow students to understand the disadvantages of each option and problems that could occur, in order to minimize them. In summary, this practical lesson gives a tool for improving the future phenotyping works of students during their careers, teaching them to consider the best software prior to analysis in order to improve the digitalizing step according to software restrictions, and to obtain more accurate information with a reduction of working time, thus increasing efficiency., Carla Guijarro-Real is grateful to the Ministerio de Educación, Cultura y Deporte of Spain for a predoctoral FPU grant (FPU14-06798). Pietro Gramazio is grateful to Universitat Politècnica de València for a post-doctoral contract (PAID-10-18) within the Programa de Ayudas de Investigación y Desarrollo initiative. Mariola Plazas is grateful to Generalitat Valenciana and Fondo Social Europeo for a post-doctoral grant (APOSTD/2018/014). Ana M Adalid-Martínez is grateful to the Ministerio de Ciencia, Innovación y Universidad of Spain for its support with a post-doctoral contract (PTA2015- 11502-I) within the Subprograma Personal Técnico de Apoyo initiative.

This chapter presents a brief description of the most relevant applications of plant biotechnology, with examples of specific techniques that can be used to provide commercial products and services to customers and represent, therefore, business opportunities to entrepreneurs. Start-up companies can base their activities on the development of molecular markers, their use in MAS (marker-assisted selection) for molecular breeding programmes or in genetic fingerprinting applications; on the use of mutagenesis for generation of mutant collections in species of interest, the development of novel mutant detection methods and the phenotypic or molecular analysis of the mutants; or on applications of in vitro culture techniques. These are all services that can be offered to small breeding companies and research laboratories that do not have in-house facilities to perform these activities. Small start-ups cannot afford to bring a novel transgenic crop variety to the market; they can, however, develop and characterise the initial transgenic lines with traits of interest and transfer them (for a price) to big transnational companies, which can undertake all further field tests and marketing procedures. It can also be profitable to use GM plants as biofactories for the production of high added-value recombinant proteins or other biomolecules for different industries. Other topics included in this chapter are the applications of ‘omics’ technologies in plant biotechnology, the new business opportunities opened by the customers’ increasing interest in the products of organic agriculture and the possible commercial exploitation of some of the thousands of compounds—phytochemicals—synthesised by plants.

[EN] Silverleaf nightshade (Solanum elaeagnifolium Cav.) is a drought tolerant invasive weed native to the New World. Despite its interest for common eggplant (S. melongena L.) breeding, up to now no success has been obtained in introgression breeding of eggplant with American Solanum species. Using an interspecific hybrid between common eggplant and S. elaeagnifolium as maternal parent we were able to obtain several fruits with viable seed after pollination with S. melongena pollen. Twenty individuals of the first backcross (BC1) generation were crossed again to the S. melongena parent and second backcross (BC2) seed was obtained for 17 of them, suggesting that most of the genome of S. elaeagnifolium is likely to be represented in the set of BC2 families. Five plants of each of the two parents, interspecific hybrid and BC1 generation were characterized with morphological descriptors and for pollen viability. The interspecific hybrid was intermediate among parents, although in overall morphological characteristics more similar to the S. elaeagnifolium parent. However, pollen viability of the hybrid was very low (2.6%). The BC1 generation was intermediate in characteristics between the hybrid and the S. melongena parent, with pollen viability increasing to an average of 19.4%. The root system of the inter specific hybrid indicated that it is able to explore larger areas of the soil than the S. melongena parent. The phenolics profile of the fruit of the two parents and hybrid revealed a higher diversity in phenolic constituents in S. elaeagnifolium compared to S. melongena, where the major phenolic compound was chlorogenic acid, while the interspecific hybrid was intermediate. By using flow cytometry it was found that S. elaeagnifolium, S. melongena, and their interspecific hybrid were diploid, although the genome size of S. elaeagnifolium was slightly smaller than that of S. melongena. Our results represent the first report of successful development of backcross generations of common eggplant with a New World Solarium species. This makes available a relatively unexplored, phylogenetically distant genepool for eggplant breeding. The backcross materials obtained can make a relevant contribution to developing new eggplant cultivars with new nutritional and environmental properties., This work was undertaken as part of the initiative "Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives", which is supported by the Government of Norway. The project is managed by the Global Crop Diversity Trust with the Millennium Seed Bank of the Royal Botanic Gardens, Kew and implemented in partnership with national and international gene banks and plant breeding institutes around the world. For further information see the project website: http://www.cwrdiversity.org/.Funding was also received from the European Union's Horizon 2020 Research and Innovation Programme under grant agreement No. 677379 (G2P-SOL project: Linking genetic resources, genomes and phenotypes of Solanaceous crops) and from Spanish Ministerio de Economia, Industria y Competitividad and Fondo Europeo de Desarrollo Regional (grant AGL2015-64755-R from MINECO/FEDER). Edgar Garcia-Fortea is grateful to Universitat Politecnica de Valencia for a pre-doctoral (Programa FPI de la UPV-Subprograma 1/2017 call) contract. Giulio Mangino is grateful to Conselleria d'Educacio, Investigacio, Cultura i Esport de la Generalitat Valenciana for a predoctoral grant within the Santiago Grisolia programme (GRISOLIAP/2016/012). Mariola Plazas is grateful to Spanish Ministerio de Economia, Industria y Competitividad for a postdoctoral grant within the Juan de la Cierva programme (FCJI-2015-24835), and to Conselleria d'Educacio, Investigacio, Cultura i Esport de la Generalitat Valenciana and Fons Social Europeu for a postdoctoral grant (APOSTD/2018/014).

[EN] Pepper (Capsicum spp.) is one of the most important vegetable crops; however, pepper genomic studies lag behind those of other important Solanaceae. Here we present the results of a high-throughput genotyping-by-sequencing (GBS) study of a collection of 190 Capsicum spp. accessions, including 183 of five cultivated species (C. annuum, C. chinense, C. frutescens, C. baccatum, and C. pubescens) and seven of the wild form C. annuum var. glabriusculum. Sequencing generated 6,766,231 high-quality read tags, of which 40.7% were successfully aligned to the reference genome. SNP calling yielded 4083 highly informative segregating SNPs. Genetic diversity and relationships of a subset of 148 accessions, of which a complete passport information was available, was studied using principal components analysis (PCA), discriminant analysis of principal components (DAPC), and phylogeny approaches. C. annuum, C. baccatum, and C. chinense were successfully separated by all methods. Our population was divided into seven clusters by DAPC, where C. frutescens accessions were clustered together with C. chinense. C. annuum var. glabriusculum accessions were spread into two distinct genetic pools, while European accessions were admixed and closely related. Separation of accessions was mainly associated to differences in fruit characteristics and origin. Phylogeny studies showed a close relation between Spanish and Mexican accessions, supporting the hypothesis that the first arose from a main genetic flow from the latter. Tajima's D statistic values were consistent with positive selection in the C. annuum clusters, possibly related to domestication or selection towards traits of interest. This work provides comprehensive and relevant information on the origin and relationships of Spanish landraces and for future association mapping studies in pepper., This work has been financed by INIA projects RTA2013-00022-C02, RTA2014-00041-C02-02, and RF2010-00025-00-00, FEDER funds. Authors are also grateful to the different Research Institutions, scientists, and breeders, and PDOs and GPIs Regulatory Boards, included on Supplementary Data: Table 1 for providing part of the materials studied here.

[EN] Background. Fool's watercress (Apium nodiflorum) is an edible vegetable with potential as a new crop. However, little information is available regarding the antioxidant properties of the plant and the individual phenolics accounting for this capacity are unknown. Methods. The antioxidant properties of twenty-five wild populations were analysed and individual phenolics present in the species reported and compared with celery and parsley. The antioxidant activity was measured as the 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) free radical scavenging capacity, and the total phenolics content (TPC) via the Folin-Ciocalteu procedure. The individual phenolics constituents were determined via high performance liquid chromatography (HPLC) as aglycones. Results. The average DPPH and TPC of fool's watercress were 28.1 mg Trolox g-1 DW and 22.3 mg of chlorogenic acid equivalents g-1 DW, respectively, much higher than those of celery and parsley. Significant differences for both DPPH and TPC, which may be explained by either genotype or environmental factors, were detected among groups established according to geographical origin. Quercetin was identified as the major phenolic present in the leaves of the species, unlike parsley and celery, in which high amounts of apigenin and luteolin were determined. Quercetin represented 61.6% of the phenolics targeted in fool's watercress, followed by caffeic acid derivatives as main hydroxycinnamic acids. Discussion. The study reports the high antioxidant properties of fool's watercress based on a large number of populations. Results suggest that quercetin accounts for an important share of the antioxidant capacity of this potential new crop. The study also provides a basis for future breeding programs, suggesting that selection by geographical locations may result in differences in the antioxidant properties., Carla Guijarro-Real is supported by the Ministerio de Educacion, Cultura y Deporte of Spain (MECD) with a predoctoral FPU grant (FPU14-06798). There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

[EN] Peppers (Capsicum spp.) are one of the most important vegetables and their double use (vegetable or spice) and two commercial stages (unripe and fully ripe) contributed to their use in many recipes and fast diffusion from America. Nowadays, Spain is a center of diversity for C. annuum, with many landraces, offering a great opportunity for adaptation to organic cultivation. Furthermore, Capsicum peppers contain many bioactive compounds, essential to provide high added-value to these cultivars, especially for organic markets, although knowledge about the effect of organic cultivation on Capsicum fruit quality is still scarce. Here, 37 accessions of Spanish landraces and foreign materials from C. annuum and other species were grown under organic and conventional conditions and evaluated for ascorbic acid (AAC), total phenolics (TP) and total red and yellow/orange carotenoids, considering both ripening stages. A large genotypic variation was found within each ripening stage and growing condition for the studied traits. Also, both stages showed high levels, although fully ripe fruits were the richest. Organic conditions enabled higher levels in fully ripe fruits of AAC and TP on average (135 vs 117 mg.100 g(-1) and 232 vs 206 mg.100 g(-1)) and in most accessions, although the genotype x growing conditions interaction also contributed, but at lower extent, to the observed variation. Significant genotype x ripening stage and growing conditionsxripening stage interactions were also found, suggesting that the magnitude of the increase with ripening depends on the accession and growing conditions. By contrast, there were no differences between growing conditions for carotenoids and differences were mainly due to the genotype factor. Finally, the large genotypic variation and favourable organic conditions allowed identifying several materials from different types and uses with very high levels of bioactive compounds for organic cultivation, in both ripening stages but particularly at fully ripe stage (>500 mg.100 g(-1))., This work has been partially funded by INIA projects RTA2014-00041-C02-02 to ARB and RTA2013-00022-C02 to AF, FEDER funds. AMRB is granted by the Universitat Politecnica de Valencia (UPV) through a scholarship within the 2017 Programa para la Formacion de Personal Investigador (FPI)-Subprograma 1, UPV-FPI 2017-Subprograma 1 -no 34. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

[EN] The need to boost agricultural production in the coming decades in a climate change scenario requires new approaches for the development of new crop varieties that are more resilient and more efficient in the use of resources. Crop wild relatives (CWRs) are a source of variation for many traits of interest in breeding, in particular tolerance to abiotic and biotic stresses. However, their potential in plant breeding has largely remained unexploited. CWRs can make an effective contribution to broadening the genetic base of crops and to introgressing traits of interest, but their direct use by breeders in breeding programs is usually not feasible due to the presence of undesirable traits in CWRs (linkage drag) and frequent breeding barriers with the crop. Here we call for a new approach, which we tentatively call 'introgressiomics', which consists of mass scale development of plant materials and populations with introgressions from CWRs into the genetic background of crops. Introgressiomics is a form of pre-emptive breeding and can be focused, when looking for specific phenotypes, or un-focused, when it is aimed at creating highly diverse intro-gressed populations. Exploring germplasm collections and identifying adequate species and accessions from different genepools encompassing a high diversity, using different strategies like the creation of germplasm diversity sets, Focused identification of germplasm strategy (FIGS) or gap analysis, is a first step in introgressiomics. Interspecific hybridization and backcrossing is often a major barrier for introgressiomics, but a number of techniques can be used to potentially overcome these and produce introgression populations. The generation of chromosome substitution lines (CSLs), introgression lines (ILs), or multiparent advanced inter-cross (MAGIC) populations by means of marker-assisted selection allows not only the genetic analysis of traits present in CWRs, but also developing genetically characterized elite materials that can be easily incorporated in breeding programs. Genomic tools, in particular high-throughput molecular markers, facilitate the characterization and development of introgressiomics populations, while new plant breeding techniques (NPBTs) can enhance the introgression and use of genes from CWRs in the genetic background of crops. An efficient use of introgressiomics populations requires moving the materials into breeding pipelines. In this respect public-private partnerships (PPPs) can contribute to an increased use of introgressed materials by breeders. We hope that the introgressiomics approach will contribute to the development of a new generation of cultivars with dramatically improved yield and performance that may allow coping with the environmental changes caused by climate change while at the same time contributing to a more efficient and sustainable agriculture., This work was undertaken as part of the initiative "Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives", which is supported by the Government of Norway. The Project is managed by the Global Crop Diversity Trust with the Millennium Seed Bank of the Royal Botanic Gardens, Kew and implemented in partnership with national and international gene banks and plant breeding institutes around the world. For further information see the project website: http://www.cwrdiversity.org/. This work has also been funded in part by European Union's Horizon 2020 research and innovation programme under Grant agreement No 677379 (G2P-SOL) and from Spanish Ministerio de Economia y Competitividad and Fondo Europeo de Desarrollo Regional (Grant AGL2015-64755-R from MINECO/FEDER, EU). Pietro Gramazio is grateful to Universitat Politecnica de Valencia for a pre-doctoral (Programa FPI de la UPV-Subprograma 1/2013 call) contract.

[EN] Conventional tomato (Solanum lycopersicum L.) descriptors are of great utility for gross morphological characterization but may not be practical for the precise fruit description required for distinguishing closely related cultivar groups. Tomato Analyzer is a new phenomics tool that provides multiple fruit morphology data from scanned images of fruit sections. We characterized 69 accessions of local tomato varieties from the region of Vale`ncia (Spain) corresponding to eight cultivar groups (Borseta, Cherry, Cor, Penjar, Plana, Pruna, Redona, and Valenciana) with 64 conventional and 38 Tomato Analyzer descriptors. Significant differences were found among accessions for all traits except for five monomorphic conventional descriptors, revealing a large diversity in the collection. Significant differences were also found among cultivar groups for 36 conventional and 37 Tomato Analyzer descriptors. The groups Borseta, Cherry, Penjar, Plana, and Pruna were clearly distinct and each of them presented many significant differences with the rest of groups. Conventional descriptors did not differentiate well the Cor, Redona, and Valenciana cultivar groups, but Tomato Analyzer descriptors clearly distinguish Valenciana from Cor and Redona groups. A multivariate principal components analysis (PCA) showed that with the exception of six (8.7 %) accessions, the different cultivar groups (including the very similar Cor and Redona) plotted in separate areas of the PCA graph. The results have shown that combined conventional and Tomato Analyzer descriptors in conjunction with PCA analysis are a powerful tool for characterization and classification of local tomato varieties, as well as for distinguishing between related cultivar groups. This has important implications for the enhancement and protection of local tomato varieties

The fruit volatile fraction of 8 Capsicum annuum and 2 Capsicum chinense accessions as well as 6 intra-specific and 2 inter-specific hybrids developed from crossings between them was isolated by headspace-solid phase microextraction (HS-SPME), and analized by gas chromatography-mass spectrometry (GC-MS). Samples of fruit flesh and placenta plus seeds were analysed separately. Several terpenoids, esters, alkanes, as well as other minor compounds relevant for the aroma, including 3-isobutyl-2-methoxypyrazine, methyl salicylate, and ¿-ionone, were identified. Remarkable differences, both qualitative and quantitative, were found for the volatile composition of the parent accessions. In hybrids a number of compounds comprised between or higher than in the corresponding parents was detected, while intermediate or transgressive inheritance for both total and individual volatiles was observed. Differences between fruit flesh and placenta/seeds were mostly quantitative, as we could not detect compound-specificity in these tissues. In most cases, both total and individual volatiles were higher in the placenta/seeds samples. This effect was particularly important in hybrids, with levels of total volatiles in the placenta up to 14-fold those of the fruit flesh. Our results suggest that there are ample opportunities for improving the aroma of Capsicum peppers by means of hybridization. © 2012 Elsevier B.V., This study has been partially financed by Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA) through Project RTA2010-00038-C03-03.

Tipa (Tipuana tipu) is a common tree in gardens and carparks, although the shading effect of its canopy must be still characterised to assess the decrease of temperature and quality of irradiance. This work is a preliminary study aimed to assess the effect of shading of tree canopies on the diffuse irradiance pattern received at the soil level in comparison to other conditions. The shade provided by a group of Tipa trees, located at the Universitat Politècnica de València (Valencia, Spain), was evaluated in this experiment and compared to cloudy days and direct sun. Photosynthetic Photon Flux Density (PPFD) and red/near infrared ratios were recorded with a portable spectrometer. Measurements were recorded in January and February 2017, at 10h, 13h and 16h. Depending on the region of the spectrum and time of the day, PPFD values ranged from 0.05 to 0.42, 0.40 to 1.14, and 0.94 to 3.90 μmol·m-2·s-1, for Tipa shade, cloudy days and direct sun, respectively. The spectral analysis of PPFD in cloudy days revealed maximum values in the green region and minimum at near infrared region, while maximum PPFD for tipa shade was mostly found at near infrared, revealing higher importance of this spectral region compared to cloudy days.

Spain is one of the most important centers of diversity for Capsicum annuum peppers, and a plethora of ecotypes can be found throughout the country. These resources represent a valuable genetic pool which must be characterized in depth both morphologically and molecularly. The aim of the present work was to assess phenotypic and genotypic diversity and relationships within some Spanish pepper landraces. A collection of 12 Spanish pepper landraces and 15 foreign controls was characterized with a set of 46 descriptors from International Plant Genetic Resources Institute (IPGRI, now Bioversity International) and genotyped using Genotyping-by-Sequencing (GBS). The studied collection was genetically diverse. The morphological characterization allowed discrimination of the varieties through fruit size, growth habit and others traits. SNP-based phylogenetics clustered together Spanish accessions. Our results provide useful information of several different ecotypes to boost breeding programs.

SummaryMelon vine decline (MVD) is a complex disease for which only a few genotypes of Cucumis melo have been described as being tolerant. These genotypes were selected under different inoculum conditions, and little is known about the morphological or biochemical mechanisms of their tolerance to MVD. In order to study the tolerance mechanisms acting in different resistant sources, we conducted a comparative analysis of three tolerant (‘Doublon’, ‘Deltex’, and ‘Pat 81’) and two susceptible (‘Piel de Sapo’ and ‘Amarillo Canario’) melon cultivars. Their responses to non-infested soils, naturally infested soils, and soils artificially inoculated with the principal causal agents of MVD – Monosporascus cannonballus and Acremonium cucurbitacearum – were studied in pots in a greenhouse, and the results were compared with their field responses. We performed a combined study on lesions, root architecture, and root:vine balance. A combination of all of these traits can predict the level of MVD tolerance in infested...

A method was developed for the specific detection, identification and quantification of Monosporascus cannonballus in infected melon roots based on real-time PCR (SYBR® Green chemistry) targeting the ITS1 region of the rDNA conserved between different strains of the pathogen. The specificity of the reaction was assessed using a number of fungi taxonomically and ecologically related to M. cannonballus. The method was highly sensitive and M. cannonballus was first detected in the roots of a susceptible Piel de Sapo cultivar 2 days after inoculation, before symptom appearance. Although conventional PCR methods could also provide such a specific and sensitive detection, real-time PCR was also able to produce reliable quantitative data over a range of 4 orders of magnitude (from 5 ng to 0.3 pg). The method allowed the quantitative monitoring of fungal growth from the very first stages of infection, and was successfully employed in the early screening of resistance. The assessment of disease progress and severity obtained with real-time PCR was more accurate than that obtained with the visual scoring of root lesions or root biomass losses. Therefore, there exists a great potential for its implementation in those steps of breeding programmes where high accuracy is required.