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Wheat has undergone a complex evolutionary history, which led to allopolyploidization and the hexaploid bread wheat Triticum aestivum. However, the significance of wheat genomic architecture for beneficial plant-microbe interactions is poorly understood, especially from a functional standpoint. In this study, we tested the hypothesis that wheat genomic architecture was an overriding factor determining root recruitment of microorganisms with particular plant-beneficial traits. We chose five wheat species representing genomic profiles AA (Triticum urartu), BB {SS} (Aegilops speltoides), DD (Aegilops tauschii), AABB (Triticum dicoccon) and AABBDD (Triticum aestivum) and assessed by qPCR their ability to interact with free-nitrogen fixers, 1-aminocyclopropane-1-carboxylate deaminase producers, 2,4-diacetylphloroglucinol producers and auxin producers via the phenylpyruvate decarboxylase pathway, in combination with Illumina MiSeq metabarcoding analysis of N fixers (and of the total bacterial community). We found that the abundance of the microbial functional groups could fluctuate according to wheat genomic profile, as did the total bacterial abundance. N fixer diversity and total bacterial diversity were also influenced significantly by wheat genomic profile. Often, rather similar results were obtained for genomes DD (Ae. tauschii) and AABBDD (T. aestivum), pointing for the first time that the D genome could be particularly important for wheat-bacteria interactions. This article is protected by copyright. All rights reserved.

For the palaeo-ecological development and interpretation of the macrofauna (Bivalvia and Gastropoda) of the Eemian Sea in the southwestern Baltic Sea region (NE Germany), up to date studies and summarising assessments are largely missing. With the main goal of revising the Eemian marine fauna, the authors have undertaken numerous new samplings in recent years. This study begins by focusing on the Warnow Bay in today's Warnow valley near Rostock. In addition to examining older data from the literature, the sandpit at Schwaan and drillings of the State Geological Survey from Boitin, Reez and Rostock were studied. Parallel to this, was also undertaken pollen analyses. Despite hundreds of drillings from the region of the former Warnow Bay, evidence of the marine Eemian was relatively rare. Apparently the sandy sediments were reworked and redistributed by glaciotectonic, glaciofluvial and fluvial processes during the Weichselian glaciation. There is as yet no definite proof of autochthonous marine sediments. They are predominantly shallow-marine sands several meters thick which are found mostly at a depth of about 30–20 m b.s.l. but more rarely also relatively close to the surface in opencast mining or cliff sections. The sands are rich in marine mollusc fauna of which 29 species have been identified so far and which also include Lusitanian specimens such as Acanthocardia paucicostata, Lucinella divaricata or Polititapes senescens. Account was also taken of accompanying marine fauna such as barnacles and echinoderms. In addition, the sediments contain fresh water molluscs also including the interglacial indicator species Belgrandia germanica.

Due to the advances in DNA markers, kompetitive allele-specific PCR (KASP) markers could accelerate breeding programs and genetically improve drought tolerance. Two previously reported KASP markers, TaDreb-B1 and 1-FEH w3, were investigated in this study for the marker-assisted selection (MAS) of drought tolerance. Two highly diverse spring and winter wheat populations were genotyped using these two KASP markers. The same populations were evaluated for drought tolerance at seedling (drought stress) and reproductive (normal and drought stress) growth stages. The single-marker analysis revealed a high significant association between the target allele of 1-FEH w3 and drought susceptibility in the spring population, while the marker–trait association was not significant in the winter population. The TaDreb-B1 marker did not have any highly significant association with seedling traits, except the sum of leaf wilting in the spring population. For field experiments, SMA revealed very few negative and significant associations between the target allele of the two markers and yield traits under both conditions. The results of this study revealed that the use of TaDreb-B1 provided better consistency in improving drought tolerance than 1-FEH w3.

A sedimentological, geochronological, and geodynamic investigation of detailed micro- and meso-scale soft-sediment deformation structures (SSDS) within internally deformed layers on Gnitz Peninsula, Usedom Island, Germany, was performed in the last years. Five layers with SSDS were described of which four were possibly caused by glacial isostatic adjustment (GIA)-triggered earthquakes mirrored in liquefaction and reliquefaction phenomena (Pisarska-Jamroży et al., 2022). Hence, in line with earlier investigations and suggestions by Hoffmann and Reicherter (2012), the SSDS generation is related to oscillation of the Scandinavian Ice Sheet whose loading cycle caused stress changes likely releasing local earthquakes along pre-existing faults.Optically stimulated luminescence dating indicates a most probable time span of corresponding earthquake occurrence between 23.2 and 14.6 ka (including uncertainty). For the first time, glacially induced Coulomb failure stress changes were modelled for this area with a set of commonly accepted GIA models. They strongly support the interpretation of SSDS trapped in layers as seismites during that time. Using reliable fault parameters of faults in near vicinity of Gnitz Peninsula and suggested stress regimes and directions for northern Germany, the modelling can help indicate the most probable reactivated pre-Quaternary fault(s). If they can be confirmed after detailed palaeoseismological, geomorphological, geophysical, and structural investigations as so-called glacially induced fault(s), this would add another puzzle piece to a geodynamic scenario of glacially triggered faulting having affected an area from northern central Europe to northern Fennoscandia in the Late Pleistocene and Early Holocene.Our presentation will focus on the geodynamic setting of NE Germany, how it was changed during the last glaciation and how potentially reactivated faults can be determined.ReferencesHoffmann, G., Reicherter, K., 2012. Soft-sediment deformation of late Pleistocene sediments along the southwestern coast of the Baltic Sea (NE Germany). Int. J. Earth Sci. 101, 351-363, doi:10.1007/s00531-010-0633-z.Pisarska-Jamroży, M., Belzyt, S., Börner, A., Hoffmann, G., Kenzler, M., Rother, H., Steffen, R., Steffen, H., 2022. Late Pleistocene earthquakes imprinted on glaciolacustrine sediments at Gnitz Peninsula (Usedom Island, NE Germany). Quat. Sci. Rev. 296C, 107807, doi:10.1016/j.quascirev.2022.107807.

Plant genetic resources are stored and regenerated in > 1750 gene banks storing > 7,000,000 accessions. Since seeds are the primary storage units, research on seed longevity is of particular importance. Quantitative trait loci (QTL) analysis of 15 traits related to seed longevity and dormancy using 7584 high-quality SNPs recorded across 2 years and originated from five production years revealed a total of 46 additive QTLs. Exploration of the QTLs with epistatic effect resulted in the detection of 29 pairs of epistatic QTLs. To our information, this is only the second report of epistatic QTLs for seed longevity in bread wheat. We conclude that in addition to dense genetic maps, the epistatic interaction between loci should be considered to capture more variation which remained unnoticed in additive mapping.

Climate instability in the Eemian Interglacial is gaining more and more evidence. One of such oscillations in the Beckentin record is indicated by the disappearance of the Cladocera and changes in macroremains at the beginning of E4a (Corylus phase). They confirm the shallowing of the reservoir, probably caused by climate changes, but not reflected in the palynological record. However, a significant oscillation observed in the first half of the E5 (Carpinus phase), ~5860 years after the boreal forests subsided and ~6290 years after the onset of interglacial forestation, suggests that, although not being an analogue of the OHO (Older Holsteinian Oscillations) in MIS 11c and the 8.2 ka cold event in the Holocene, it is very similar to these oscillations. The Eemian oscillation was noted also in the Bispingen profile in northern Germany, ~6500 years after the interglacial forestation. However, the course of vegetation changes there differs from that in Beckentin. The analysis of macroremains and Cladocera confirms the disappearance of rush and water vegetation in the water reservoir at that time in Beckentin. These results confirm that numerous climatic oscillations could have occurred in the Eemian Interglacial.

The continuous increase in global population prompts increased wheat production. Future wheat (Triticum aestivum L.) breeding will heavily rely on dissecting molecular and genetic bases of wheat yield and related traits which is possible through the discovery of quantitative trait loci (QTLs) in constructed populations, such as recombinant inbred lines (RILs). Here, we present an evaluation of 92 RILs in a bi-parental RIL mapping population (the International Triticeae Mapping Initiative Mapping Population [ITMI/MP]) using newly generated phenotypic data in 3-year experiments (2015), older phenotypic data (1997-2009), and newly created single nucleotide polymorphism (SNP) marker data based on 92 of the original RILs to search for novel and stable QTLs. Our analyses of more than 15 unique traits observed in multiple experiments included analyses of 46 traits in three environments in the USA, 69 traits in eight environments in Germany, 149 traits in 10 environments in Russia, and 28 traits in four environments in India (292 traits in 25 environments) with 7584 SNPs (292 × 7584 = 2 214 528 data points). A total of 874 QTLs were detected with limit of detection (LOD) scores of 2.01-3.0 and 432 QTLs were detected with LOD 3.0. Moreover, 769 QTLs could be assigned to 183 clusters based on the common markers and relative proximity of related QTLs, indicating gene-rich regions throughout the A, B, and D genomes of common wheat. This upgraded genotype-phenotype information of ITMI/MP can assist breeders and geneticists who can make crosses with suitable RILs to improve or investigate traits of interest.

Milk thistle, Silybum marianum (L.) Gaertn. (Asteraceae), is an economically important medicinal plant utilized for silymarin production. Moreover, the species has been positively evaluated for vegetable oil and biomass production. Despite these positive characteristics, milk thistle is still marked by traits that are typical of undomesticated species (most importantly natural fruit dispersal at maturity) and requires further genetic improvement for its complete exploitation. This manuscript summarizes all the information collected through time about a collection of nine milk thistle wild and mutant lines and it discusses the possible further utilization of these genotypes. The accessions are characterized by interesting traits related to: fruit silymarin composition (S. marianum chemotype A and B), fruit fatty acid composition (high oleic and high stearic acid lines), fruit condensed tannins content, vegetative biomass composition (modification of xylans or lignin content), vegetative biomass structure (dwarf and tall lines), modifications of leaf variegation (hypervareigated line) and different types of fruit shatter resistance at maturity. All the lines underwent subsequent generations of selfing and are stable for all the described traits. The accessions will be made available at the Genebank of the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK, Gatersleben) and may prove to be a useful genetic material for the improvement of qualitative fruit traits (silymarin quality, fatty acid composition) and for the further development of shatter-resistant S. marianum genotypes towards the complete domestication of this promising species.

Key Message: Association genetic analysis empowered us to identify candidate genes underlying natural variation of morpho-physiological, antioxidants, and grain yield-related traits in barley. Novel intriguing genomic regions were identified and dissected. Abstract: Salinity stress is one of the abiotic stresses that influence the morpho-physiological, antioxidants, and yield-related traits in crop plants. The plants of a core set of 138 diverse barley accessions were analyzed after exposure to salt stress under field conditions during the reproductive phase. A genome-wide association scan (GWAS) was then conducted using 19,276 single nucleotide polymorphisms (SNPs) to uncover the genetic basis of morpho-physiological and grain-related traits. A wide range of responses to salt stress by the accessions was explored in the current study. GWAS detected 263 significantly associated SNPs with the antioxidants, K+/Na+ content ratio, and agronomic traits. Five genomic regions harbored interesting putative candidate genes within LD ± 1.2 Mbp. Choromosome 2H harbored many candidate genes associated with the antioxidants ascorbic acid (AsA) and glutathione (GSH), such as superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR), under salt stress. Markedly, an A:C SNP at 153,773,211 bp on chromosome 7H is located inside the gene HORVU.MOREX.r3.7HG0676830 (153,772,300–153,774,057 bp) that was annotated as l-gulonolactone oxidase, regulating the natural variation of SOD_S and APX_S. The allelic variation at this SNP reveals a negative selection of accessions carrying the C allele, predominantly found in six-rowed spring landraces originating from Far-, Near-East, and central Asia carrying photoperiod sensitive alleles having lower activity of enzymatic antioxidants. The SNP-trait associations detected in the current study constitute a benchmark for developing molecular selection tools for antioxidant compound selection in barley.

Here we report radiocarbon measurements made on wheat seed tissue (Triticum aestivum L.; winter or spring type growth habit), from the seed archive of the IPK Gatersleben, Sachsen-Anhalt, Germany, which was harvested between 1946 and 2020. The results give an overview of 75 years of radiocarbon concentration evolution in agricultural plant products. The wheat tissue radiocarbon concentrations follow known pre- and post-bomb radiocarbon records, such as the atmospheric Jungfraujoch, Schauinsland, and NH1 datasets. Based on a Northern Hemisphere growing period from April to July, the Gatersleben seed tissue radiocarbon concentration indicates incorporation of fossil carbon of about 1% with respect to the high alpine, clean-air CO2 of the Jungfraujoch station between 1987 and 2019. We propose to use the pre- and post-bomb radiocarbon record of Gatersleben wheat as a reference in forensic investigations, such as the age estimation of paper by analyzing starch used in paper manufacture. Additionally, an advantage of the record reported here lies in its extensibility by adding new analyses from future harvests.

In non-celiac gluten sensitivity (NCGS), the elimination of wheat results in a clear symptom improvement, but gluten has still not been proven as (the sole) trigger. Due to the increase in the prevalence of gluten-related diseases, the breeding of high-performance wheat cultivars is discussed as a trigger. To analyze the immune stimulation and signal pathways, the immune cells of healthy subjects and patients with NCGS were stimulated with gliadins from wheat, and the expression and secretion of interleukin 1ß (IL1ß) and interleukin 6 (IL6) were studied. To determine the impact of wheat breeding, the monocyte cell line THP1 and human immune cells were stimulated with gliadin, glutenin, and albumin/globulin fractions of ancient and modern cereals, and expression of inflammatory molecules was checked. Immune cells of patients with NCGS showed an increased expression of IL1ß and IL6 after stimulation with gliadins compared to immune cells of healthy controls. Gliadins caused a strong activation of P-STAT3 in immune cells of healthy controls, and inhibitors of JAK and NFκB pathways considerably reduced this response. In addition to gliadins, we further showed that glutenins and albumin/globulins from all wheat cultivars from the last century, and especially from einkorn and spelt, also markedly induced the expression of inflammatory genes in THP1 and human immune cells. There was no correlation between enhanced immune stimulation and ancient or modern cultivars. This does not support the hypothesis that modern wheat breeding is responsible for the increase in gluten-related diseases. An altered immune situation is suggested in patients with NCGS.

Increased salinity is one of the major consequences of climatic change affecting global crop production. The early stages in the barley (

The genetic diversity among an international collection of 40 maize accessions has been evaluated using DNA ISSR fingerprinting. Among the 180 ISSR markers scored by 15 primers, 161 markers (89.59%) were polymorphic and 19 were unique in 16 accessions. A cluster tree based on the average distance coefficients and the Dice similarity indices divided the accessions into three major groups, each including clusters of accessions assigned to their subspecies. However, a low level of genetic differentiation among the accessions was demonstrated by the STRUCTURE analysis of ISSR data in agreement with the low gene flow (Nm) value among the accessions. A scatter diagram of the principal component analysis (PCA) based on ISSR data analysis revealed that the accessions were differentiated into three groups comparable to those produced by the cluster analysis, in which some accessions of the same subspecies showed a close similarity to each other. A scatter diagram of the principal coordinate analysis (PCoA) based on the drought tolerance indices (DTIs) showed that nine genetically similar accessions share drought tolerance characteristics; these include four of subsp. indurata, three of subsp. everata, and two of subsp. indentata. An abundance of unique ISSR alleles found in the 16 accessions, including the nine drought-tolerant accessions, represents rich untapped genetic resources and these accessions may be exploited in the future breeding of maize commercial lines.

One hundred years ago N.I. Vavilov formulated the Law of homologous series in hereditary variability. Among the broad range of examples that encouraged N.I. Vavilov to make this important generalization, homologous series in plant height variability were mentioned. In the current review, we compare data collected over the century on genetic basis and molecular mechanisms behind the series in plant height variability with the stress on “Green revolution” genes. Application of fertilizers boosted redirection of artificial selection from tall-growing varieties to those with reduced height. The sources of GA-sensitive and GA-insensitive reduced height (Rht) genes in wheat and rice first were involved in crosses in Japan and China. The commercially valuable alleles of the Rht genes were spread broadly in varieties released in 1960s all over the world. Results of genetic studies into inheritance of the Rht genes are summarized for rice and wheat (together with further Triticeae crops–barley and rye). Three orthologous series of reduced plant height genes have been found within Triticeae tribe species and rice: (1) wheat Rht12 and rye Ddw1; (2) wheat Rht-B1/D1 and barley Dwf2; (3) barley denso/sdw1 and rice sd1. Molecular and cell mechanisms underlying plant reduced height are considered with focus on metabolic pathways regulated by commercially valuable alleles of Rht genes: GA-insensitive Rht-B1/D1 and GA-sensitive sd1, denso/sdw1, Rht8, Rht12, Rht18, Ddw1. Overall, in spite of similar metabolic pathways, the certain genes conferring variability for plant height are often distinct, resulting in existence of several “short” orthologous series of genes rather than one series through different cereal taxa.

The properties of the root system are especially important under drought, which is currently the most significant climate threat worldwide. The aim of this work was to investigate the relationship between the root system development and vernalization requirements under contrasting irrigation conditions in bread wheat using lines with alien introgressions. A set of single chromosome substitution lines Chinese Spring (Synthetic 6x, AABBDD) and D-genome derived introgression lines were used to study the relationships. It was found that 1A substitution resulted in a substantial reduction of root length and weight while 5D substitution, on the contrary, led to a significant increase compared to the recipient and the donor under both irrigation regimes. The greatest root weight, root length, and number of days to flowering were detected in the lines carrying a common introgression fragment of the 5D chromosome connected with the molecular marker Xgwm292 and the Vrn-D1 gene. The lines with the introgression in this region had a significantly larger root length and weight compared with the recipient and donor under all conditions of irrigation. The combination of prolonged vernalization and drought negatively affected the development of roots in all lines with the most pronounced effect on root weight. With the use of monosomic analysis, it was shown that the Vrn-A1 gene has a substantial reducing effect on the root length and weight. The revealed relationship between the flowering time and root system development can be used for breeding of wheat cultivars more adapted for growing in arid conditions.

Delayed luminescence (DL) has been widely studied for its applications in developmental biology and describes a phenomenon whereby biological materials radiate for a relatively long time (seconds and more) after illumination. Researchers have postulated that DL is potentially useful for determining the physiological status of biological materials, including crop seeds. Until recently this claim only remained within academia and there have been no known reports for the advancement of its use in seed testing and genebank management. This article examines the gaps in knowledge for adopting DL for seed testing by reviewing the history of DL applications in analytical studies of crop seeds and the incompletely understood mechanisms within seeds for displaying DL. We identified a need for more experimental data to validate the DL mechanisms in seeds before the procedure can be used for seed testing.

Microsatellite (SSR) markers with known precise intrachromosomal locations are widely used for mapping genes in rye and for the investigation of wheat-rye translocation lines and triticale highly demanded for mapping economically important genes and QTL-analysis. One of the sources of novel SSR markers in rye are microsatellites transferable from the wheat genome. Broadening the list of available SSRs in rye mapped to chromosomes is still needed, since some rye chromosome maps still have just a few microsatellite loci mapped. The goal of the current study was to integrate wheat EST-SSRs into the existing rye genetic maps and to construct a consensus rye microsatellite map. Four rye mapping populations (P87/P105, N6/N2, N7/N2 and N7/N6) were tested with CFE (EST-SSRs) primers. A total of 23 Xcfe loci were mapped on rye chromosomes: Xcfe023, -136 and -266 on chromosome 1R, Xcfe006, -067, -175 and -187 on 2R, Xcfe029 and -282 on 3R, Xcfe004, -100, -152, -224 and -260 on 4R, Xcfe037, -208 and -270 on 5R, Xcfe124, -159 and -277 on 6R, Xcfe010, -143 and -228 on 7R. With the exception of Xcfe159 and Xcfe224, all the Xcfe loci mapped were found in orthologous positions considering multiple evolutionary translocations in the rye genome relative to those of common wheat. The consensus map was constructed using mapping data from the four bi-parental populations. It contains a total of 123 microsatellites, 12 SNPs, 118 RFLPs and 2 isozyme loci.Микросателлитные (SSR) маркеры широко используют для картирования генов ржи и анали- за транслокационных линий пшеницы и тритикале. SSR-маркеры с известной внутрихромосомной локализацией очень востребованы для картирования экономически значимых генов и QTL- анализа. Одним из источников новых SSR-маркеров у ржи являются микросателлитные маркеры пшеницы. Несмотря на не- сколько наборов микросателлитных маркеров, доступных у ржи, по-прежнему необходимо расширение списка SSR, сопоставленных с хромосомами ржи, поскольку на некоторых генетических картах количество SSR-маркеров невелико. Цель настоящего исследования состояла в том, чтобы интегрировать EST-SSR пшеницы в существующие генетические карты ржи и построить консенсусную микросателлитную карту ржи. Четыре картирующих популяции ржи (P87/P105, N6/N2, N7/N2 и N7/N6) тестировали с использова- нием праймеров CFE (EST-SSR). В результате в молекулярно-генетические карты ржи было интегрирова- но 23 микросателлитных локуса Xcfe: Xcfe023, -136 и -266 на хромосоме 1R, Xcfe006, -067, -175 и -187 на 2R, Xcfe029 и -282 на 3R, Xcfe004, -100, -152, -224 и -260 на 4R, Xcfe037, -208 и -270 на 5R, Xcfe124, -159 и -277 на 6R, Xcfe010, -143 и -228 на 7R. За исключением Xcfe159 и Xcfe224, все картированные локусы Xcfe были обнаружены в ортологичных позициях с учетом множественных транслокаций в ходе эволюции генома ржи по сравнению с пшеницей. Консенсусная карта построена с использованием данных по четырем картирую- щим популяциям ржи. Она содержит в общей сложности 123 микросателлитных маркера, 12 SNP, 118 RFLP и 2 изоферментных локуса.

Epidemiologic studies suggest an increasing prevalence of celiac disease and non-celiac gluten/wheat sensitivity. With wheat proteins being the main triggers, changes in wheat protein composition are discussed as a potential cause. The goals of breeding toward increased yield and resistance might have inadvertently contributed to a higher immunostimulatory potential of modern wheat cultivars compared to old wheat cultivars. Therefore, agronomic characteristics, protein content, and gluten composition of 60 German winter wheat cultivars first registered between 1891 and 2010 grown in 3 years were analyzed. While plant height and spike density decreased over time, yield and harvest index increased. The protein and gliadin contents showed a decreasing trend, whereas glutenin contents increased, but there were no changes in albumin/globulin and gluten contents. Overall, the harvest year had a more significant effect on protein composition than the cultivar. At the protein level, we found no evidence to support an increased immunostimulatory potential of modern winter wheat.

The genomic landscape of recombination plays an essential role in evolution. Patterns of recombination are highly variable along chromosomes, between sexes, individuals, populations, and species. In many eukaryotes, recombination rates are elevated in sub-telomeric regions and drastically reduced near centromeres, resulting in large low-recombining (LR) regions. The processes of recombination are influenced by genetic factors, such as different alleles of genes involved in meiosis and chromatin structure, as well as external environmental stimuli like temperature and overall stress. In this work, we focused on the genomic landscapes of recombination in a collection of 916 rye (Secale cereale) individuals. By analyzing population structure among individuals of different domestication status and geographic origin, we detected high levels of admixture, reflecting the reproductive biology of a self-incompatible, wind-pollinating grass species. We then analyzed patterns of recombination in overlapping subpopulations, which revealed substantial variation in the physical size of LR regions, with a tendency for larger LR regions in domesticated subpopulations. Genome-wide association scans (GWAS) for LR region size revealed a major quantitative-trait-locus (QTL) at which, among 18 annotated genes, an ortholog of histone H4 acetyltransferase ESA1 was located. Rye individuals belonging to domesticated subpopulations showed increased synaptonemal complex length, but no difference in crossover frequency, indicating that only the recombination landscape is different. Furthermore, the genomic region harboring rye ScESA1 showed moderate patterns of selection in domesticated subpopulations, suggesting that larger LR regions were indirectly selected during domestication to achieve more homogeneous populations for agricultural use.

Conservation of plant genetic diversity is fundamental for crop improvement, increasing agricultural production and sustainability, especially in the face of climatic changes. Although seed longevity is essential for the management of seed banks, few studies have, so far, addressed differences in this trait among the accessions of a single species. Eight Pisum sativum L. (pea) accessions were investigated to study the impact of long-term (approximately 20 years) storage, aiming to reveal contrasting seed longevity and clarify the causes for these differences. The outstanding seed longevity observed in the G4 accession provided a unique experimental system. To characterize the biochemical and physical status of stored seeds, reactive oxygen species, lipid peroxidation, tocopherols, free proline and reducing sugars were measured. Thermoanalytical measurements (thermogravimetry and differential scanning calorimetry) and transmission electron microscopy combined with immunohistochemical analysis were performed. The long-lived G4 seeds neither consumed tocopherols during storage nor showed free proline accumulation, as a deterioration hallmark, whereas reducing sugars were not affected. Thermal decomposition suggested a biomass composition compatible with the presence of low molecular weight molecules. Expansion of heterochromatic areas and reduced occurrence of γH2AX foci were highlighted in the nucleus of G4 seeds. The longevity of G4 seeds correlates with the occurrence of a reducing cellular environment and a nuclear ultrastructure favourable to genome stability. This work brings novelty to the study of within-species variations in seed longevity, underlining the relevance of multidisciplinary approaches in seed longevity research.

Association genetic analysis empowered us to identify candidate genes underlying natural variation of morpho-physiological, antioxidants, and grain yield-related traits in barley. Novel intriguing genomic regions were identified and dissected. Salinity stress is one of the abiotic stresses that influence the morpho-physiological, antioxidants, and yield-related traits in crop plants. The plants of a core set of 138 diverse barley accessions were analyzed after exposure to salt stress under field conditions during the reproductive phase. A genome-wide association scan (GWAS) was then conducted using 19,276 single nucleotide polymorphisms (SNPs) to uncover the genetic basis of morpho-physiological and grain-related traits. A wide range of responses to salt stress by the accessions was explored in the current study. GWAS detected 263 significantly associated SNPs with the antioxidants, K

A core set of 138 diverse barley accessions were exposed to salt stress under field conditions at the reproductive phases, and then a genome-wide association scan (GWAS) was conducted using 19,276 single nucleotide polymorphisms (SNPs) to uncover the genetic basis of morpho-physiological and agronomic traits. A wide range of responses among the accessions to the salt stress was explored in the current study. GWAS detected 299 significantly associated SNPs with the antioxidants, K+/Na+ ratio, and agronomic traits. Five genomic regions harbor interesting putative candidate genes within LD ±1.2 Mbp. Exclusively, 2H harbors many candidate genes associated with antioxidant contents such as SOD, APX, GR, AsA, and GSH under salt stress. Markedly, on chromosome 7H at 153773211 bp, A:C SNP is physically located inside the gene HORVU.MOREX.r3.7HG0676830.1 (153,772,300- 153,774,057 bp) that annotated as L-gulonolactone oxidase, regulating the natural variation of SOD_S and APX_S. The allelic variation at this SNP reveals a negative selection of accessions carrying C allele which are predominantly landraces originated from Far-, Near-East carrying photoperiod sensitive alleles having lower activity of enzymatic antioxidants. The SNP-trait associations detected in the current study constitute a benchmark for developing molecular selection tools for antioxidant compound selection in barley.

Background and aims Pb and Sn concentration increase rapidly due to the industrial revolution and cause a significant reduction in wheat production and productivity. Understanding the genetic control of Pb and Sn tolerance is very important to produce wheat cultivars that are tolerant to such metals. Methods Extensive genetic analyses using genome-wide association study, functional annotation, and gene enrichment were investigated in a set of 103 highly diverse spring wheat genotypes. Kernel traits such as kernel length (KL), kernel diameter (KD), kernel width (KW), and 1000-kernel weight (TKW) were measured under each metal as well as under controlled conditions. Results The GWAS identified a total of 131, 126, and 115 markers that were associated with kernel traits under Ctrl, Pb, and Sn. Moreover, the stress tolerance index (STI) for Pb and Sn was calculated and GWAS revealed 153 and 105 significant markers, respectively. Remarkably, one SNP Ku_c269_2643 located within TraesCS2A02G080700 gene model was found to be associated with KL under the three conditions. The results of gene enrichment revealed three, three, and six gene networks that have an association with the processes involved in kernel formation. The target alleles of all significant markers detected by GWAS were investigated in the most tolerant wheat genotypes to truly select the candidate parents for crossing in future breeding programs. Conclusion This is the first study that unlocked the genetic control of kernel yield under controlled and heavy metals conditions. Understanding the genetic control of kernel traits under heavy metals will accelerate breeding programs to improve wheat tolerance to Pb and Sn.

Seed storage is important to farmers, breeders and for germplasm preservation. During storage, seeds accumulate damage at the structural and metabolic level, which disrupt their function and reduce resistance to adverse external conditions. In this regard, issues related to seed aging prove to be relevant for maintaining the viability of genetic collections. We analyzed morphological characteristics of grains and their coat color for 44 recombinant inbred lines (RILs) of bread wheat grown in four different seasons, 2003, 2004, 2009 and 2014. Our investigations were performed in 2020. For 19 RILs from the same seasons germination was evaluated. Our results demonstrate that genotype significantly affects the variability of all seed traits, and the year of harvesting affects about 80% of them (including all the traits of shape and size). To identify the trend between changes in grain characteristics and harvesting year, we estimated correlation coefficients between them. No significant trend was detected for the grain shape/size traits, while 90% of the color traits demonstrated such a trend. The most significant negative correlations were found between the harvesting year and the traits of grain redness: the greater the storage time, the more intensive is red color component for the grains. At the same time, it was shown that grains of longer storage time (earlier harvesting year) have lighter coat. Analysis of linear correlations between germination of wheat seeds of different genotypes and harvesting years and their seed traits revealed a negative linear relationship between the red component of coat color and germination: the redder the grains, the lower their germination rate. The results obtained demonstrate manifestations of metabolic changes in the coat of grains associated with storage time and their relationship with a decrease of seed viability.