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In the dynamic landscape of agriculture and food science, incorporating emergent crops appears as a pioneering solution for diversifying agriculture, unlocking possibilities for sustainable cultivation and nutritional bolstering food security, and creating economic prospects amid evolving environmental and market conditions with positive impacts on human health. This review explores the potential of utilizing emergent crops in Mediterranean environments under current climate scenarios, emphasizing the manifold benefits of agricultural and food system diversification and assessing the impact of environmental factors on their quality and consumer health. Through a deep exploration of the resilience, nutritional value, and health impacts of neglected and underutilized species (NUS) such as quinoa, amaranth, chia, moringa, buckwheat, millet, teff, hemp, or desert truffles, their capacity to thrive in the changing Mediterranean climate is highlighted, offering novel opportunities for agriculture and functional food development. By analysing how promoting agricultural diversification can enhance food system adaptability to evolving environmental conditions, fostering sustainability and resilience, we discuss recent findings that underscore the main benefits and limitations of these crops from agricultural, food science, and health perspectives, all crucial for responsible and sustainable adoption. Thus, by using a sustainable and holistic approach, this revision analyses how the integration of NUS crops into Mediterranean agrifood systems can enhance agriculture resilience and food quality addressing environmental, nutritional, biomedical, economic, and cultural dimensions, thereby mitigating the risks associated with monoculture practices and bolstering local economies and livelihoods under new climate scenarios. [ABSTRACT FROM AUTHOR]

There is a need to generate improved crop varieties adapted to the ongoing changes in the climate. We studied durum wheat canopy and central metabolism of six different photosynthetic organs in two yield-contrasting varieties. The aim was to understand the mechanisms associated with the water stress response and yield performance. Water stress strongly reduced grain yield, plant biomass, and leaf photosynthesis, and down-regulated C/N-metabolism genes and key protein levels, which occurred mainly in leaf blades. By contrast, higher yield was associated with high ear dry weight and lower biomass and ears per area, highlighting the advantage of reduced tillering and the consequent improvement in sink strength, which promoted C/N metabolism at the whole plant level. An improved C metabolism in blades and ear bracts and N assimilation in all photosynthetic organs facilitated C/N remobilization to the grain and promoted yield. Therefore, we propose that further yield gains in Mediterranean conditions could be achieved by considering the source–sink dynamics and the contribution of non-foliar organs, and particularly N assimilation and remobilization during the late growth stages. We highlight the power of linking phenotyping with plant metabolism to identify novel traits at the whole plant level to support breeding programmes. [ABSTRACT FROM AUTHOR]

An acceleration of the genetic advances of durum wheat, as a major crop for the Mediterranean region, is required, but phenotyping still represents a bottleneck for breeding. This study aims to define durum wheat ideotypes under Mediterranean conditions by selecting the most suitable phenotypic remote sensing traits among different ones informing on characteristics related with leaf pigments/photosynthetic status, crop water status, and crop growth/green biomass. A set of 24 post-green revolution durum wheat cultivars were assessed in a wide set of 19 environments, accounted as the specific combinations of a range of latitudes in Spain, under different management conditions (water regimes and planting dates), through 3 consecutive years. Thus, red-green-blue and multispectral derived vegetation indices and canopy temperature were evaluated at anthesis and grain filling. The potential of the assessed remote sensing parameters alone and all combined as grain yield (GY) predictors was evaluated through random forest regression models performed for each environment and phenological stage. Biomass and plot greenness indicators consistently proved to be reliable GY predictors in all of the environments tested for both phenological stages. For the lowest-yielding environment, the contribution of water status measurements was higher during anthesis, whereas, for the highest-yielding environments, better predictions were reported during grain filling. Remote sensing traits measured during the grain filling and informing on pigment content and photosynthetic capacity were highlighted under the environments with warmer conditions, as the late-planting treatments. Overall, canopy greenness indicators were reported as the highest correlated traits for most of the environments and regardless of the phenological moment assessed. The addition of carbon isotope composition of mature kernels was attempted to increase the accuracies, but only a few were slightly benefited, as differences in water status among cultivars were already accounted by the measurement of canopy temperature. [ABSTRACT FROM AUTHOR]

This study explores the potential of Spanish germplasm for the development of hybrids adapted to southern Europe, a new region for hybrid barley (Hordeum vulgare). A set of 140 locally adapted, advanced breeding lines, developed in a Spanish public breeding program, were evaluated for their potential to widen the germplasm available for hybrid barley development. A subset of 24 lines was introduced into three‐way hybrid combinations and tested in a field trial network of four locations and 2 yr. The hybrid performance of the rest of the lines was estimated based on genomic prediction models. No three‐way hybrid exceeded the best check. We succeeded in identifying lines with high general combining ability, which could produce promising two‐way hybrids. Some were among those tested in the field, whereas others resulted from genomic predictions, validating the strategy followed of mining locally adapted breeding lines. Rachis brittleness detected in field trials revealed a low but detrimental effect of the presence of alternative brittle mutations in the hybrid combination. The success of hybrid breeding in southern Europe requires further investigation of the underlying heterotic patterns, and appropriate management of brittle genes through prebreeding, to widen the germplasm accessible for hybrid barley breeding. Core Ideas: A combination of field testing and genomic prediction successfully mined local germplasm for hybrid development.Reduced expression of local diversity and heterosis in three‐way hybrids hampered obtaining superior hybrids.High‐yielding, widely adapted, parental lines for the development of promising two‐way hybrids were identified.Field‐estimation of rachis fragility indicates risk of grain loss in hybrids with alternative brittle mutations.The success of hybrid barley in southern Europe requires managing flowering time and studying heterotic patterns. [ABSTRACT FROM AUTHOR]

The integration of high-throughput phenotyping and metabolic approaches is a suitable strategy to study the genotype-by-environment interaction and identify novel traits for crop improvement from canopy to an organ level. Our aims were to study the phenotypic and metabolic traits that are related to grain yield and quality at canopy and organ levels, with a special focus on source-sink coordination under contrasting N supplies. Four modern durum wheat varieties with contrasting grain yield were grown in field conditions under two N fertilization levels in north-eastern Spain. We evaluated canopy vegetation indices taken throughout the growing season, physiological and metabolic traits in different photosynthetic organs (flag leaf blade, sheath, peduncle, awn, glume, and lemma) at anthesis and mid-grain filling stages, and agronomic and grain quality traits at harvest. Low N supply triggered an imbalance of C and N coordination at the whole plant level, leading to a reduction of grain yield and nutrient composition. The activities of key enzymes in C and N metabolism as well as the levels of photoassimilates showed that each organ plays an important role during grain filling, some with a higher photosynthetic capacity, others for nutrient storage for later stages of grain filling, or N assimilation and recycling. Interestingly, the enzyme activities and sucrose content of the ear organs were positively associated with grain yield and quality, suggesting, together with the regression models using isotope signatures, the potential contribution of these organs during grain filling. This study highlights the use of holistic approaches to the identification of novel targets to improve grain yield and quality in C3 cereals and the key role of non-foliar organs at late-growth stages. [ABSTRACT FROM AUTHOR]

Summary: Durum wheat is an important cereal that is widely grown in the Mediterranean basin. In addition to high yield, grain quality traits are of high importance for farmers. The strong influence of climatic conditions makes the improvement of grain quality traits, like protein content, vitreousness, and test weight, a challenging task. Evaluation of quality traits post‐harvest is time‐ and labor‐intensive and requires expensive equipment, such as near‐infrared spectroscopes or hyperspectral imagers. Predicting not only yield but also important quality traits in the field before harvest is of high value for breeders aiming to optimize resource allocation. Implementation of efficient approaches for trait prediction, such as the use of high‐resolution spectral data acquired by a multispectral camera mounted on unmanned aerial vehicles (UAVs), needs to be explored. In this study, we have acquired multispectral image data with an 11‐band multispectral camera mounted on a UAV and analyzed the data with machine learning (ML) models to predict grain yield and important quality traits in breeding micro‐plots. Combining 11‐band multispectral data for 34 cultivars and 16 environments allowed to develop ML models with good prediction capability. Applying the trained models to test sets explained a considerable degree of phenotypic variance with good accuracy showing r squared values of 0.84, 0.69, 0.64, and 0.61 and normalized root mean squared errors of 0.17, 0.07, 0.14, and 0.03 for grain yield, protein content, vitreousness, and test weight, respectively. Significance Statement: The results of this study show that combining data from a multispectral camera mounted on an unmanned aerial vehicle with machine learning is a powerful approach to efficiently predict important quality traits and yield pre‐harvest at the micro‐plot level. Robust prediction can be achieved by providing selected spectral wavebands directly to machine learning models. [ABSTRACT FROM AUTHOR]

Understanding the interaction between genotype performance and the target environment is the key to improving genetic gain, particularly in the context of climate change. Wheat production is seriously compromised in agricultural regions affected by water and heat stress, such as the Mediterranean basin. Moreover, wheat production may be also limited by the nitrogen availability in the soil. We have sought to dissect the agronomic and physiological traits related to the performance of 12 high-yield European bread wheat varieties under Mediterranean rainfed conditions and different levels of N fertilization during two contrasting crop seasons. Grain yield was more than two times higher in the first season than the second season and was associated with much greater rainfall and lower temperatures. However, the nitrogen effect was rather minor. Genotypic effects existed for the two seasons. While several of the varieties from central/northern Europe yielded more than those from southern Europe during the optimal season, the opposite trend occurred in the dry season. The varieties from central/northern Europe were associated with delayed phenology and a longer crop cycle, while the varieties from southern Europe were characterized by a shorter crop cycle but comparatively higher duration of the reproductive period, associated with an earlier beginning of stem elongation and a greater number of ears per area. However, some of the cultivars from northern Europe maintained a relatively high yield capacity in both seasons. Thus, KWS Siskin from the UK exhibited intermediate phenology, resulting in a relatively long reproductive period, together with a high green area throughout the crop cycle. [ABSTRACT FROM AUTHOR]

Chenopodium quinoa Willd (quinoa) has acquired an increased agronomical and nutritional relevance due to the capacity of adaptation to different environments and the exceptional nutritional properties of their seeds. These include high mineral and protein contents, a balanced amino acid composition, an elevated antioxidant capacity related to the high phenol content, and the absence of gluten. Although it is known that these properties can be determined by the environment, limited efforts have been made to determine the exact changes occurring at a nutritional level under changing environmental conditions in this crop. To shed light on this, this study aimed at characterizing variations in nutritional-related parameters associated with the year of cultivation and different genotypes. Various nutritional and physiological traits were analyzed in seeds of different quinoa cultivars grown in the field during three consecutive years. We found differences among cultivars for most of the nutritional parameters analyzed. It was observed that the year of cultivation was a determinant factor in every parameter studied, being 2018 the year with lower yields, germination rates, and antioxidant capacity, but higher seed weights and seed protein contents. Overall, this work will greatly contribute to increase our knowledge of the impact of the environment and genotype on the nutritional properties of quinoa seeds, especially in areas that share climatic conditions to Southern Europe. [ABSTRACT FROM AUTHOR]

The regulation of plant transpiration was proposed as a key factor affecting transpiration efficiency and agronomical adaptation of wheat to water-limited Mediterranean environments. However, to date no studies have related this trait to crop performance in the field. In this study, the transpiration response to increasing vapor pressure deficit (VPD) of modern Spanish semi-dwarf durum wheat lines was evaluated under controlled conditions at vegetative stage, and the agronomical performance of the same set of lines was assessed at grain filling as well as grain yield at maturity, in Mediterranean environments ranging from water stressed to good agronomical conditions. A group of linear-transpiration response (LTR) lines exhibited better performance in grain yield and biomass compared to segmented-transpiration response (STR) lines, particularly in the wetter environments, whereas the reverse occurred only in the most stressed trial. LTR lines generally exhibited better water status (stomatal conductance) and larger green biomass (vegetation indices) during the reproductive stage than STR lines. In both groups, the responses to growing conditions were associated with the expression levels of dehydration-responsive transcription factors (DREB) leading to different performances of primary metabolism-related enzymes. Thus, the response of LTR lines under fair to good conditions was associated with higher transcription levels of genes involved in nitrogen (GS1 and GOGAT) and carbon (RCBL) metabolism, as well as water transport (TIP1.1). In conclusion, modern durum wheat lines differed in their response to water loss, the linear transpiration seemed to favor uptake and transport of water and nutrients, and photosynthetic metabolism led to higher grain yield except for very harsh drought conditions. The transpiration response to VPD may be a trait to further explore when selecting adaptation to specific water conditions. [ABSTRACT FROM AUTHOR]

Although the relevance of spike bracts in stress acclimation and contribution to wheat yield was recently revealed, the metabolome of this organ and its response to water stress is still unknown. The metabolite profiles of flag leaves, glumes and lemmas were characterized under contrasting field water regimes in five durum wheat cultivars. Water conditions during growth were characterized through spectral vegetation indices, canopy temperature and isotope composition. Spike bracts exhibited better coordination of carbon and nitrogen metabolisms than the flag leaves in terms of photorespiration, nitrogen assimilation and respiration paths. This coordination facilitated an accumulation of organic and amino acids in spike bracts, especially under water stress. The metabolomic response to water stress also involved an accumulation of antioxidant and drought tolerance related sugars, particularly in the spikes. Furthermore, certain cell wall, respiratory and protective metabolites were associated with genotypic outperformance and yield stability. In addition, grain yield was strongly predicted by leaf and spike bracts metabolomes independently. This study supports the role of the spike as a key organ during wheat grain filling, particularly under stress conditions and provides relevant information to explore new ways to improve wheat productivity including potential biomarkers for yield prediction. [ABSTRACT FROM AUTHOR]

Modern plant breeding practices have narrowed the genetic base of wheat throughout the world, increasing crop vulnerability. Therefore, there is clearly a need for introducing new germplasm in breeding programs to search for variability related to traits of agronomic interest for wheat improvement. The existence of subsets of accessions (core collections) that represent the diversity conserved in germplasm collections is a favored approach for breeders to explore novel variation and enhance the use of germplasm. In this study, a core collection of Spanish landraces of bread wheat has been created using high-throughput genotyping technologies (DArTseq), which yielded more than 50 K molecular markers. This marker system not only provides a robust estimate of the diversity, but also information about its distribution in the genome. Two core collections of 94 entries were created by using two common sampling strategies: the maximization strategy and the population structure-based method. Both core collections showed high geographic, phenotypic and genetic representativeness, but the collection obtained with the maximization strategy captured better the diversity displayed by the initial collection. This core collection, which includes a broad range of adapted genotypes, can be efficiently utilized for mining new alleles for useful traits in wheat breeding. [ABSTRACT FROM AUTHOR]

While crop breeding represents a key factor in terms of effectiveness and affordability in the adaptation of agriculture to stress conditions, phenotyping is perceived as a major bottleneck to achieving genetic advance. Crops in the field experience the simultaneous occurrence of multiple stresses, which vary depending on the location, year and management conditions. Even under the so-called "optimal agronomic conditions", crops under field conditions may experience some degree of stress. The review addresses the methodology of field phenotyping in environments with multiple stresses where genotype by environment (and even by management) interactions are common, the ideotypes that may work, and the phenotypic traits that characterise such ideotypes that are the most useful for identifying better adapted genotypes. Mediterranean wheat is taken as a case study. Integrative phenotypic traits have intrinsic value in terms of information about crop adaptability to growing conditions in a wide sense, thus inherently accounting for the occurrence of "hidden" stresses. Indeed, this has implications when considering genotype by environment interactions. Thus, such integrative traits, when evaluated under real (i.e. field) conditions, account for the crop's performance under scenarios where the interaction between environmental growing conditions is the norm. Three categories of traits may comprise the ideotypic characteristics when phenotyping wheat for Mediterranean environments: phenology, water status and plant growth. While these characteristics are not fully independent of each other, they should represent the crop's performance reasonably well over a wide range of Mediterranean scenarios. It is in such a context that this review examines the case of wheat and other small grain cereals growing under Mediterranean conditions and illustrates how a few phenotyping traits, related to crop growth, water status and phenology, may define ideotypes well adapted to a wide range of environmental conditions, where non-crossover interactions exist. This is despite the fact that across such a range of environmental conditions, multistressors are present and are variable in nature, intensity and timing. Thus, for a wide range of Mediterranean conditions, the genotypes chosen correspond to ideotypes that exhibit more effective use of water and stronger growth. It is not only the characteristics of the ideotypes, but also the appropriate phenotypic traits characterising these ideotypes that are integrative in nature, meaning that they inform about crop performance over time (e.g. stable carbon isotope composition) and/or at the highest organisational level (e.g. canopy assessed via remote sensing). At the functional level, these traits guide improvements in the capture of resources such as water or radiation, rather than how efficiently these resources are being used. • Crops in the field experience simultaneous occurrence of multiple stresses. • Ideotypes can be formulated based on characters phenotyped with integrative traits. • A few traits may define wheat ideotypes that are well adapted to a wide range of Mediterranean conditions. • Classical ways to display GxE interaction help to assess trait performance across growing conditions. • These traits guide improvements in the capture of resources, rather than how efficiently they are being used. [ABSTRACT FROM AUTHOR]

Highlights • Genetic gain of durum wheat in Spain slowed after the green revolution until reach a plateau in the last decade. • However, genetic gain was positively related with the mean and maximum daily temperatures of the testing sites. • The genetic advance was related to improvement in kernels m−2 and kernels spike−1. Abstract This paper addresses the question of whether there has been any genetic gain in yield for durum wheat released in Spain after the Green Revolution and assesses the agronomical and physiological traits associated with evolution of the crop during this time. Field experiments were carried out with a wide range of durum wheat cultivars (released in Spain from 1980 to 2009) and were conducted in different sites embracing a wide range of growing temperatures and water regimes at Aranjuez and Zamadueñas during three consecutive growing seasons (2013/14, 2014/15, 2015/16) under rainfed and supplemental irrigation and at Coria for two consecutive seasons (2014/15 and 2015/16) under rainfed conditions alone. Grain yield increased with the year of release of cultivars at a rate of 24 kg ha−1 y−1 (0.44% y−1) from 1980 to 2003, with no clear additional improvements thereafter. The moderate grain yield improvement from 1980 and 2003 was associated with kernels m−2 and kernels spike−1, with an increase of 117 kernels m−2 y−1 and 0.24 kernels spike−1 y−1, respectively. Moreover, aerial biomass at harvest and grain nitrogen yield increased with the year of release of cultivars for the entire period. However, no differences were found for thousand kernel weight, number of spikes m−2, days to heading, plant height, harvest index, canopy temperature depression, carbon isotope discrimination or grain nitrogen concentration. Overall, these results indicated that the rate of genetic progress in the yield of durum wheat in Spain after the Green Revolution has been low and has even stopped during the last decade, while no clear trend in some grain quality traits (TKW and grain N concentration) was recorded. However, the absolute and relative genetic gains estimated for yield were positively associated with the average mean and maximum daily temperatures from sowing to harvest of the testing site, which suggest that breeding has been performed under high-temperature environments. [ABSTRACT FROM AUTHOR]

Identifying traits conferring high yield in target environments has become a main concern of wheat breeders. This is particularly relevant for the current Mediterranean conditions as well as for the expected scenarios driven by climate change for central and northern Europe. The objective of this study was to identify breeding traits conferring adaption of high-yielding European wheat cultivars to actual Mediterranean conditions. Twelve elite winter wheat cultivars from different European (northern, central and southern) regions were grown under Mediterranean continental conditions across three consecutive crop seasons and three different topdressing nitrogen fertilization levels. Phenology was assessed throughout the crop cycle. At maturity, grain yield (GY), grain number and thousand kernel weight (TKW) were determined. Further, carbon (δ13C) and nitrogen (δ15N) stable isotope compositions and nitrogen concentration (N) were analyzed in mature grains as proxies for water and nitrogen status, respectively. The nitrogen fertilization effect was minor for GY compared with the season and genotypic effects. Concerning genotypic performance, the effect of phenology varied across seasons, with longer crop durations being associated with higher GY under the wettest season (2017–2018), no effect under mildly wet conditions (2019–2020) and being negatively associated with GY under dry conditions (2018–2019). Furthermore, the relative duration of each phenological stage had an effect on genotypic performance, particularly during the dry season (2018–2019). Moreover, regardless of the season considered, the highest-yielding genotypes were associated with better water status (lower δ13C). Under wet season conditions, northern European genotypes had 6 % higher yields, whereas in the dry season, southern European genotypes had 2 % higher yields. The differences in GY among the top wheat cultivars originating from different European regions were fairly minor across the seasons and across the N fertilization levels recommended in the region. The study suggests that, depending on the season, selection for the high-yielding conditions of central and northern Europe also delivers genetic increases in grain yield under Mediterranean conditions. • Recommended N topdressing levels place wheat fertilization in the saturation zone. • Genotypic yield performance is associated with higher grain number rather than weight. • Crop duration and phenology are key to adapting genotypes to Mediterranean conditions. • Regardless of the season, the best genotypes exhibit better water status (lower δ13C). • Some northern European wheat cultivars are well adapted to Mediterranean conditions. [ABSTRACT FROM AUTHOR]

Crop performance is very dependent on roots because they determine the capture of water and nutrients, and the crop's subsequent growth and productivity. Durum wheat is a major crop in the Mediterranean region, where water and nitrogen availability limit its productivity. Therefore, the focus of this study was to uncover the response of root and shoot traits in durum wheat to different Mediterranean growing conditions and how they relate to better growth and yield performance. For this purpose, crop performance was evaluated in a set of modern durum wheat cultivars grown during four consecutive seasons and under contrasting water regimes, temperatures and nitrogen supplies, totalling 12 different growing conditions. Grain yield, biomass, other crop-growth traits (plant height, PH, and the Normalised Difference Vegetation Index, NDVI), together with physiological indicators of water (carbon isotope composition, δ13C, and canopy temperature depression, CTD) and nitrogen (nitrogen isotope composition, δ15N, and grain nitrogen yield, GNY) status were assessed. In addition, root architecture and distribution were measured using shovelomics and soil coring, and the provenance of the water captured by roots was determined by comparing the oxygen (δ18O) and hydrogen (δ2H) isotope compositions of water at the base of the stem, with water in different soil sections. Water and nitrogen status indicators combined with shovelomic traits allowed development of yield-prediction models. while higher yields were associated in most cases with better water status, root architecture was very responsive to different growing conditions. Overall, genotypes better adapted to rainfed conditions exhibited roots favouring deeper water extraction, whereas under support irrigation, the root system enabled water extraction from the topsoil as from deeper soil sections. Our study also highlights the limitation of shovelomics and soil coring as phenotyping approaches and proposes the δ18O of stem water as a promising functional phenotypic approach. [Display omitted] • Water availability is the main environmental factor limiting durum wheat yield. • Durum wheat root architecture shows high plasticity under Mediterranean conditions. • Under rainfed conditions, higher yields are associated with deeper roots. • Under irrigation, higher yielding crops combined shallow and deep roots. • We propose the δ18O of stem water as a phenotypic trait informing about soil water uptake. [ABSTRACT FROM AUTHOR]