Wheat has a pivotal role in food chains and human diet, and the understanding of its productive and qualitative performance under elevated CO2 (e[CO2]) is therefore a primary research target. While e[CO2] generally boosts wheat yield and biomass, major concerns remain about the impact on qualitative traits. The use of biochar as amendment, thanks to its well-known ability to improve soil fertility and crop production and quality, could be a suitable solution to cope with the negative effect of e[CO2] on qualitative traits. To test this hypothesis, we present the results of an open field experiment investigating the combined effects of biochar application and e [CO2] on quantitative and qualitative performance of two commercial durum wheat (Triticum durum) cultivars (Aureo and Claudio). The experimental design included plots treated without [B0] or with 30 t ha-1 of biochar as amendment [B30] and grown at ambient a[CO2] and e[CO2] (570 ppm). Results indicated that biochar increased soil temperatures by +1 degrees C during winter, thus favouring an earlier phenology and average biomass (+10 % and +7.2 %) and yield (+13.2 % and +8.5 %) increase in both a[CO2] and e[CO2] treatments compared to the no biochar [B0] treatments. Biochar treatments also increased flag leaf chlorophyll and decreased flavonoids, and enhanced intrinsic water use efficiency due to increases in photosynthesis and decreases in stomatal conductance. Spike density, falling number and thousand kernel weight were positively and significantly altered by biochar amendment, whilst the remaining parameters mostly differed between cultivars only. By contrast, biochar application did not alleviate nitrogen reduction in grains and straw in both cultivars neither increase grain protein content, although it remained sufficient for pasta making under all treatment combinations. Accordingly, biochar use could be preferentially adopted for increasing the productivity of high-quality cultivars whose destination and industrial processing would not suffer from a decrease in quality parameters.

Reduced-tillering wheat (Triticum aestivum L.) lines carrying the tin (tiller inhibition) gene are characterized by high spike fertility and high grain weights. These traits may enable high yields under favorable climatic conditions, provided that the low tillering is offset by an adequate sowing rate. Field trials were conducted to evaluate the effect of the tin gene by comparing two pairs of near-isogenic lines (NILs), namely Janz ± tin and Kite ± tin, sown at a rate of 350 germinable seeds m-² across six environments (two sites × three years) in Italy (Sardinia and Emilia-Romagna). Seasonal rainfall (October–May) ranged from 311 to 784 mm, corresponding to mean grain yields between 3.5 and 6.7 t ha-1. On average, the tin lines yielded similarly to their free-tillering counterparts (4.67 vs. 4.78 t ha-1, respectively), owing to their higher grain weight (45.0 vs. 42.3 mg), which compensated for a lower grain number (10408 vs. 11554 m-²) resulting from fewer spikes m-2 (406 vs. 437), despite a similar number of grains per spike. The reduced fruiting efficiency of tin lines (56.0 vs. 65.6 grains g-1 of spike), likely due to an inefficient investment in chaff, may have constrained the expression of their typically high spike fertility. However, the lower spike number plasticity in tin lines was balanced by greater plasticity in grain weight, enabling comparable grain yield plasticity between NILs. Although the grain yield level and plasticity of tin lines were comparable to those of free-tillering lines, these results do not support their adoption in cropping systems targeting moderate to high yields. On the other hand, the findings do not rule out the potential benefits of introgressing tin genes into different genetic backgrounds or improving fruiting efficiency to overcome the limitations identified in this study.

Agriculture faces great challenges to overcome global warming and improve system sustainability, requiring access to novel genetic diversity. So far, wild populations and local landraces remain poorly explored. This is notably the case for the two diploid species, Brassica oleracea L. (CC, 2n=2x=18) and B. rapa L. (AA, 2n=2x=20). In order to explore the genetic diversity in both species, we have collected populations in their centre of origin, the Mediterranean basin, on a large contrasting climatic and soil gradient from northern Europe to southern sub-Saharan regions. In these areas, we also collected 14 populations belonging to five B. oleracea closely related species. Our objective was to ensure the absence of species misidentification at the seedling stage among the populations collected and to describe thereafter their origins. We combined flow cytometry, sequencing of a species-specific chloroplast genomic region, as well as cytogenetic analyses in case of unexpected results for taxonomic verification. Out of the 112 B. oleracea and 154 B. rapa populations collected, 103 and 146, respectively, presented a good germination rate and eighteen populations were misidentified. The most frequent mistake was the confusion of these diploid species with B. napus. Additionally for B. rapa, two autotetraploid populations were observed. Habitats of the collected and confirmed wild populations and landraces are described in this study. The unique plant material described here will serve to investigate the genomic regions involved in adaptation to climate and microbiota within the framework of the H2020 Prima project ‘BrasExplor’.

Oats are small grain cereals with a low carbon footprint, great significance in circular agriculture and in sustainable crop production, characterized by peculiar content in primary and secondary metabolites, which fits into a healthy food diet. Varietal innovation is a training factor to promote the cultivation of this cereal and allele mining is one of the pieces of the puzzle that supports breeding new varieties improved for agronomic and qualitative traits. This approach can be effectively used for discovery of superior alleles through "mining" the gene of interest from diverse genetic resources, ranging from germplasm collections to mutant ones, obtained, e.g., via Eco-TILLING and TILLING strategies. Wide collections of oat genetic resources are available worldwide in several private and public collections and Gene Banks, as the result of a decades-long effort by botanists and geneticists. Consequently, oat germplasm is included in the top 10 genetic resource collections held by Gene Banks. Core collections, useful to discover new alleles, have been developed in the frame of several projects and consortia. Novel genetic variation has been obtained with a TILLING approach and the derived populations are now available to study specific traits. Finally, high-quality genome references of oats at different ploidy level have been recently developed and are now available to the research community, as the primary starting point for an efficient allele mining activity.

Awns illustrate an important photosynthetic organ of the cereal spike, especially under water stress. Barley (Hordeum vulgare L.) spikes are distinguished by long awns; nevertheless, the actual changes in barley awn dimensions under drought stress have not been adequately studied. In the present work, six barley genotypes with varying degrees of drought tolerance were investigated in a 2-year field experiment under well-watered (WW) and terminal drought stress (TDS) conditions based on randomized complete block design with three replications. The results showed that although TDS caused a notable reduction in awn dimensions compared to WW, the density of barbs on the awn surface significantly increased in all barley genotypes. In addition, the barb contact angle decreased significantly under TDS conditions compared to WW. Awn area had a significantly positive correlation with thousand grain weight and grain yield in both treatments and growing seasons. Also, highly significant correlations were observed between leaf stomatal conductance, awn area, and barb density under both conditions. In TDS, two genotypes demonstrated lower carbon isotope discrimination: Morocco, with higher awn dimensions, and PBYT 46, with a higher increase in barbs density on the awn surface and a lower canopy temperature. This research underlines barbs density on the awn surface by reflecting the light and a lower increase in the canopy temperature plays a more pivotal role than awn dimensions on water use efficiency in barley under terminal drought.

Solina is an example of a bread wheat landrace that has been conserved in situ for centuries in Central Italy. A core collection of Solina lines sampled in areas at different altitudes and climatic conditions was obtained and genotyped. A clustering analysis based on a wide SNP dataset generated from DArTseq analysis outlined the existence of two main groups, which, after Fst analysis, showed polymorphism in genes associated with vernalization and photoperiod response. Starting from the hypothesis that the different pedoclimatic environments in which Solina lines were conserved may have shaped the population, some phenotypic characteristics were studied in the Solina core collection. Growth habit, low-temperature resistance, allelic variations at major loci involved in vernalization response, and sensitivity to photoperiod were evaluated, together with seed morphologies, grain colour, and hardness. The two Solina groups showed different responses to low temperatures and to photoperiod-specific allelic variations as well as the different morphology and technological characteristics of the grain. In conclusion, the long-term in situ conservation of Solina in environments sited at different altitudes has had an impact on the evolution of this landrace which, despite its high genetic diversity, remains clearly identifiable and distinct so as to be included in conservation varieties.

Agriculture faces great challenges to overcome global warming and to improve system sustainability, requiring access to novel genetic diversity. So far, wild populations and local landraces remain poorly explored. This is notably the case for the two diploid species, Brassica oleracea L. (CC, 2n=2x=18) and B. rapa L. (AA, 2n=2x=20). In order to explore genetic diversity in both species, we have collected numerous populations in their center of origin, the Mediterranean basin, on a large contrasting climatic and soil gradient from northern Europe to southern sub-Saharan regions. In these areas, we also collected 14 populations belonging to five B. oleracea closely related species. Before further genetic and agronomic investigations, we controlled the absence of species misidentification using flow cytometry, sequencing of species specific chloroplast genomic region, as well as cytogenetic analyses in case of unexpected results. Looking at the 102 B. oleracea and 146 B. rapa populations showing a good germination among the 112 and 154 populations collected, seventeen populations were misidentified. The most frequent mistake was a confusion of these diploid species with B. napus . Additionally for B. rapa , 2 autotetraploid populations were observed. Habitats of the collected wild populations and landraces are described in our work. This provides a unique plant material characterization that will pave the way for further analyses investigating the genomic regions involved in climatic and microbiota adaptation. This research is supported by the H2020 Prima project ‘BrasExplor’.

Triticale is currently grown throughout the world with a wider diffusion in Europe, with Poland, Belarus, Germany, France and Spain as major producers. Although triticale occupies a very small fraction of the Italian cultivated land (16,000 ha of harvested area, mean value of the past 5 years), a continuous interest for this crop and its possible uses explains the work and progress made by breeding activities in different periods. The aim of this review is to report some experiences related to the cultivation of triticale in Italy. A general long-term view of the performance of triticale varieties in Italy has been distilled from a large amount of data derived from the pluri-decennial Italian national variety trials network. This activity, historically coordinated by CREA-GB, extends over several decades and examines the agronomic performance, in different Italian environments, of the most widespread and emerging varieties of triticale. Indications on new breeding targets can be deduced from the elaborations in the frame of both climatic change and market demands.

Exome sequencing-based allele mining for frost tolerance suggests HvCBF14 rather than CNV at Fr-H2 locus is the main responsible of frost tolerance in barley. Wild relatives, landraces and old cultivars of barley represent a reservoir of untapped and potentially important genes for crop improvement, and the recent sequencing technologies provide the opportunity to mine the existing genetic diversity and to identify new genes/alleles for the traits of interest. In the present study, we use frost tolerance and vernalization requirement as case studies to demonstrate the power of allele mining carried out on exome sequencing data generated from > 400 barley accessions. New deletions in the first intron of VRN-H1 were identified and linked to a reduced vernalization requirement, while the allelic diversity of HvCBF2a, HvCBF4b and HvCBF14 was investigated by combining the analysis of SNPs and read counts. This approach has proven very effective to identify gene paralogs and copy number variants of HvCBF2 and the HvCBF4b-HvCBF2a segment. A multiple linear regression model which considers allelic variation at these genes suggests a major involvement of HvCBF14, rather than copy number variation of HvCBF4b-HvCBF2a, in controlling frost tolerance in barley. Overall, the present study provides powerful resource and tools to discover novel alleles at relevant genes in barley.

While the general effect of CO2 enrichment on photosynthesis, stomatal conductance, N content, and yield has been documented, there is still some uncertainty as to whether there are interactive effects between CO2 enrichment and other factors, such as temperature, geographical location, water availability, and cultivar. In addition, the metabolic coordination between leaves and grains, which is crucial for crop responsiveness to elevated CO2, has never been examined closely. Here, we address these two aspects by multi-level analyses of data from several free-air CO2 enrichment experiments conducted in five different countries. There was little effect of elevated CO2 on yield (except in the USA), likely due to photosynthetic capacity acclimation, as reflected by protein profiles. In addition, there was a significant decrease in leaf amino acids (threonine) and macroelements (e.g. K) at elevated CO2, while other elements, such as Mg or S, increased. Despite the non-significant effect of CO2 enrichment on yield, grains appeared to be significantly depleted in N (as expected), but also in threonine, the S-containing amino acid methionine, and Mg. Overall, our results suggest a strong detrimental effect of CO2 enrichment on nutrient availability and remobilization from leaves to grains.

Eggplant (Solanum melongena L.) yield is highly sensitive to N fertilization, the excessive use of which is responsible for environmental and human health damage. Lowering N input together with the selection of improved Nitrogen-Use-Efficiency (NUE) genotypes, more able to uptake, utilize, and remobilize N available in soils, can be challenging to maintain high crop yields in a sustainable agriculture. The aim of this study was to explore the natural variation among eggplant accessions from different origins, in response to Low (LN) and High (HN) Nitrate (NO3-) supply, to identify NUE-contrasting genotypes and their NUE-related traits, in hydroponic and greenhouse pot experiments. Two eggplants, AM222 and AM22, were identified as N-use efficient and inefficient, respectively, in hydroponic, and these results were confirmed in a pot experiment, when crop yield was also evaluated. Overall, our results indicated the key role of N-utilization component (NUtE) to confer high NUE. The remobilization of N from leaves to fruits may be a strategy to enhance NUtE, suggesting glutamate synthase as a key enzyme. Further, omics technologies will be used for focusing on C-N metabolism interacting networks. The availability of RILs from two other selected NUE-contrasting genotypes will allow us to detect major genes/quantitative trait loci related to NUE.

Eggplant (Solanum melongena L.) yield is highly sensitive to N fertilization, whose excessive use is responsible of environment and human health damages. Lowering N input together with the selection of improved Nitrogen-Use-Efficiency (NUE) genotypes, more able to uptake, utilize and remobilize N available in soils, could be challenging to maintain high crop yields in a sustainable agriculture. The aim of this study was to explore the natural variation among eggplant accessions from different origins, in response to Low (LN) and High (HN) Nitrate (NO3 - ) supply, to identify NUE-contrasting genotypes and their NUE-related traits, in hydroponic and greenhouse pot experiments. Two eggplants, AM222 and AM22, were identified as N-use efficient and inefficient, respectively, in hydroponic, and these results were confirmed in pot experiment, when crop yield was also evaluated. Overall, our results indicated the key role of N-utilization component (NUtE) to confer high NUE. The remobilization of N from leaves to fruits may be a strategy to enhance NUtE, suggesting GS as a key enzyme. Further, -omics technologies will be employed focusing on C-N metabolism interacting networks. The availability of RILs from other two selected NUE-contrasting genotypes, will allow us to detect major genes/QTL related to NUE. This article is protected by copyright. All rights reserved.

The rising atmospheric CO2, concentration is expected to exert a strong impact on crop production, enhancing crop growth but threatening food security and safety. An improver wheat, a hybrid, and its parents were grown at elevated CO2, e[CO2] in open field, and their yield and rheological, nutritional, and sanitary quality were assessed. For all cultivars, grain yield increased (+16%) and protein content decreased (-7%), accompanied by a reduction in dough strength. Grain nitrogen yield increased (+24%) only in ordinary bread making cultivars. e[CO2] did not result in significant changes in phenolic acid content and composition, whereas it produced a significant increase in the deoxynivalenol content. Different responses to e[CO2] between cultivars were found for yield parameters, while the effect on qualitative traits was quite similar. In the upcoming wheat cropping systems, agronomic practices and cultivar selection suited to guarantee higher nitrogen responsiveness and minimization of sanitary risk are required.

Under global climate change forecasts, the pressure of environmental stressors (and in particular drought) on crop productivity is expected to rise and challenge further global food security. The application of beneficial microorganisms may represent an environment friendly tool to secure improved crop performance and yield stability. Accordingly, this current study aimed at elucidating the metabolomic responses triggered by mycorrhizal (Funneliformis mosseae) inoculation of durum (Triticum durum Desf.; cv. 'Mongibello') and bread wheat cultivars (Triticum aestivum L.; cv. 'Chinese Spring') under full irrigation and water deficit regimes. Metabolomics indicated a similar regulation of secondary metabolism in both bread and durum wheat cultivars following water limiting conditions. Nonetheless, a mycorrhizal fungi (AMF) x cultivar interaction could be observed, with the bread wheat cultivar being more affected by arbuscular colonization under water limiting conditions. Discriminant compounds could be mostly related to sugars and lipids, both being positively modulated by AMF colonization under water stress. Moreover, a regulation of metabolites related to oxidative stress and a tuning of crosstalk between phytohormones were also evidenced. Among the latter, the stimulation of the brassinosteroids biosynthetic pathway was particularly evident in inoculated wheat roots, supporting the hypothesis of their involvement in enhancing plant response to water stress and modulation of oxidative stress conditions. This study proposes new insights on the modulation of the tripartite interaction plant-AMF-environmental stress.

Climate change is increasing drought events and decreasing water availability. Tomato is commonly transplanted to an open field after seedling production in a nursery, requiring large volumes of water. Arbuscular mycorrhizal (AM) fungi help plants cope with drought stress; however, their effects depend on plant genotype and environmental conditions. In this study, we assessed the interactions among different tomato seedling genotypes and two AM fungi, Funneliformis mosseae and Rhizophagus intraradices, under two water regimes, full and reduced. Our results showed that F. mosseae was more effective than R. intraradices in the mitigation of drought stress both in old and modern genotypes. However, seedlings inoculated with R. intraradices recorded the highest values of leaf area. 'Pearson' and 'Everton' genotypes inoculated with F. mosseae recorded the highest values of root, leaf, and total dry weights under reduced and full irrigation regimes, respectively. In addition, 'Pearson' and 'H3402' genotypes inoculated with F. mosseae under a reduced irrigation regime displayed high values of water use efficiency. Our results highlight the importance of using AM fungi to mitigate drought stress in nursery production of tomato seedlings. However, the development of ad hoc AM fungal formulations, which consider genotype x AM fungi interactions, is fundamental for achieving the best agronomic performances.

Yield of processing tomato (Solanum lycopersicum L.) increased (similar to 50%) in Italy since the 1930's. The aim of this work was to assess the changes in yield components associated with morphological, physiological and fruit quality traits in processing tomato cultivars cropped in Italy from the mid-1930s until nowadays, introduced by breeding in six representative cultivars. Marketable yield showed an increase of 0.6% per year of release since the 1930's. The highest marketable yield was obtained in modem cultivars due to a higher harvest index, fruit number and the ratio between ripe fruit and total fruit in comparison with the old ones. However, no single trait drove the highest marketable yield in modem cultivars. In fact, both morphological (smaller plant height and leaf area index) and physiological (accelerated plant senescence, higher leaf nitrogen status, and lower potential plant water and chlorophyll contents) traits contributed to increase marketable yield in modem cultivars. Moreover, total plant dry weight (shoot + fruit) of a single plant decreased, whereas its total fruit fresh weight and fruit dry matter content were stable and not correlated with the year of release, thus suggesting that a higher sink strength and homogeneity of fruit ripening were also involved in the highest marketable yield showed by modern cultivars. A great effort of breeders was done in the improvement of important fruit quality traits required by Italian canning industries. Fruit colour and Brix yield were positively correlated with the year of release, while viscosity and total carotenoids were negatively correlated with the year of release. However, no improvement was achieved for important traits such as soluble solids content, fruit dry weight and total fruit yield, which instead should be considered in the future breeding programmes, to improve both yield and quality of processing tomato.

Six processing tomato seedlings, representative of cultivars widely cultivated over the last 80 years in Southern Europe, were compared to assess the physiological responses to chilling. Low temperature stress was applied for 24 h (1 degrees C, day and night). PEARSON, the oldest cultivar, reported the highest values of chlorophyll content both using DUALEX (Chl(DX) = 23.11) and SPAD (Chl(SPAD) = 35.27) and nitrogen balance index (NBIDX = 29.62) measured with DUALEX, before chilling stress. The cultivar E6203 was the least sensitive to chilling with the highest value of maximal photosystem II (PSII) efficiency (F-v/F(m)2 = 0.64) at recovery and visual regrowth score (VS3 = 4.0) at regrowth period. As regards chilling tolerance in terms of maximal PSII efficiency, few differences were observed among the cultivars, apart from C33, that was the most sensitive. On the other hand, a better regrowth was recorded in the modem ones. Strong correlations were found between the different parameters investigated both before (SPAD and DUALEX) and after the chilling stress (maximal PSII efficiency, SPAD and electrolyte leakage). SPAD values at regrowth were shown to be a good indicator of tomato chilling status at regrowth period. Analysis of genetic similarity based on microsatellite markers clearly discriminated modern and old varieties according to the year of release. This information could be useful in breeding programs for new cultivars suitable for early transplant, when chilling injury can happen.