Barley Research Articles

Determination of resistance levels of Hordeum vulgare L. cultivars grown in Türkiye against Fusarium culmorum

Determination of resistance levels of Hordeum vulgare L. cultivars grown in Türkiye against Fusarium culmorum

Transcriptome signature for multiple biotic and abiotic stress in barley (Hordeum vulgare L.) identifies using machine learning approach

Barley (Hordeum vulgare L.) is exposed to various biotic and abiotic stresses, making it crucial to fully understand the gene signatures that respond to stress. This study utilizes machine learning to analyze transcriptomic data from 515 RNA-seq profiles across 18 independent studies, covering eleven abiotic and three biotic stress types. Through meticulous data preprocessing, including quality assessment and batch effect correction, we have identified 4,311 genes for further analysis. Feature selection was performed using five weighting algorithms, resulting in the prioritization of 400 core genes. Machine learning models, specifically Random Forest and C4.5, were optimized and evaluated using a 10-fold cross-validation approach. The C4.5 algorithm demonstrated superior accuracy in predicting stress-responsive signatures. Key genes, such as bHLH119 and E3 ubiquitin protein ligase DRIP2, were identified as potential biomarkers. Functional enrichment analysis, conducted through protein-protein interaction networks and Gene Ontology/KEGG pathway analysis, has revealed significant involvement in lipid biosynthesis, signal transduction, and defense response processes. These findings highlight the crucial roles of the identified biomarkers genes in barley's resilience to stress and provide potential targets for genetic improvement. Future research should focus on validating these biomarkers in different barley cultivars and under field conditions to enhance crop resilience against stressors.

Control efficacy and joint toxicity of broflanilide mixed with commercial insecticides to an underground pest, the black cutworm in highland barley.

The highland barley, Hordeum vulgare L., is a staple food crop with superior nutritional functions in Xizang, China. It is often damaged by the black cutworm, Agrotis ipsilon (Hufnagel), which is an underground pest and difficult to effectively manage. To introduce a novel insecticide with unique mode of action, broflanilide (BFL) and its binary mixtures with chlorantraniliprole (CAP), fluxametamide, β-cypermethrin or imidacloprid were screened out as seed treatment to control black cutworm in highland barley in the present study. In the laboratory bioassays, BFL had outstanding insecticidal activity to black cutworm with a median lethal dose (LD50) of 0.07 mg kg-1. The mixture of BFL × CAP at the concentration ratio of 7:40 exhibited the highest synergistic effect with a co-toxicity coefficient of 280.48. In the greenhouse pot experiments, BFL and BFL × CAP seed treatments at 8 g a.i. kg-1 seed could effectively control black cutworm, with a low percentage of injured seedlings <20% and high control efficacies of 93.33-100% during a period of 3-12 days after seed emergence. Moreover, BFL and BFL × CAP seed treatments could promote the seed germination and seedling growth of highland barley at the tested temperatures of 15, 20 and 25 °C. Our results indicated that BFL and BFL × CAP were effective and promising insecticides as seed treatment to control black cutworm in highland barley. © 2024 Society of Chemical Industry.

AAC Lariat barley

AAC Lariat is a hulled, two-row, spring, general purpose barley ( Hordeum vulgare L.) cultivar widely adapted to western Canada. It was developed from the cross AAC Synergy/TR09398 made in 2010 and it was evaluated in the Western Cooperative Two-row Barley Registration Test (2019–2020) before being registered in 2022. With its high yield, good standability, and disease resistance, AAC Lariat will offer a good production choice for feed growers across the Prairies.

AAC Choo spring barley

‘AAC Choo’ is a spring, two-row, general purpose barley ( Hordeum vulgare L.) released by the Ottawa Research and Development Centre, Agriculture and Agri-Food Canada. AAC Choo is high in yield, good lodging resistance, and moderately susceptible to Fusarium head blight (caused by Fusarium graminearum Schwabe). AAC Choo is recommended for commercial production in eastern Canada.

Comparative study of the effect of moderate and strong sodium chloride salinization on growth and photosynthetic apparatus of cultivated cereals

In a controlled environment, the effect of moderate (100 mM) and strong (200 mM) sodium chloride salinity on seed germination, seedling growth and the state of the photosynthetic apparatus (PSA) of barley (Hordeum vulgare L.) varieties Nur and wheat (Triticum aestivum L.) varieties Zlata was studied. It was found that with moderate salinization, the seeds of both species successfully germinated, but the growth of shoots and the accumulation of aboveground biomass were inhibited, which was partly due to a slowdown in the rate of photosynthesis. With strong salinity, distinct interspecific differences were observed in the response of plants. In particular, the number of germinated seeds decreased in barley, while in wheat it remained at the control level. In barley, shoot growth was inhibited to a greater extent, whereas in wheat, the accumulation of aboveground biomass was. The content of pigments in barley plants decreased, and the content of wheat increased. At the same time, stomatal conductivity decreased in both species and the rate of photosynthesis slowed down. It is concluded that based on the energy of germination and germination of seeds, it is possible to determine the salt resistance of species only to a high level of salinity (200 mM NaCl). Morphometric indicators of shoot growth make it possible to assess the resistance of plants to salinity already at lower salt concentrations (100 mM NaCl). For a more accurate comparative assessment of the salt resistance of species (varieties, varietals, genotypes) of cereals, not one, but several indicators should be used, reflecting not only the growth potential of plants, but also photosynthetic activity.

Sensitivity of the pathogen of barley brown rust (&lt;i&gt;Puccinia hordei&lt;/i&gt; G.H. Otth.) to fungicides – derivatives of triazoles and strobilurins

The sensitivity of the North Caucasian population of the pathogen of barley brown rust (Puccinia hordei G.H. Otth.) to fungicides derived from triazoles and strobilurines (preparations Amistar Gold, SK; Amistar Extra, SK; Baliy, KME; Delaro, KS) was determined. The work was carried out under controlled conditions of the greenhouse complex of the Federal National Research and Development Fund on winter barley of the susceptible Vivat variety of the Agricultural Scientific Center “Donskoy”. Winter barley plants in the germination phase were infected with the North Caucasian population of the barley brown rust pathogen. Fungicide treatment was carried out at the first signs of the disease with application rates of 0 (control, without treatment), 50, 100, 150 and 200% (the recommended application rate is assumed to be 100%). It was found that when treating infected barley plants with the fungicide Baliy, KME with different application standards, the biological effectiveness varied from 87.3 to 100%, Delaro, KS – from 78.1 to 100%, Amistar Extra, SK – from 79.2 to 100%, Amistar Gold, SK – from 85.3 to 100%. The use of the recommended dose of treatment(100%) contributed to a decrease in the development of brown rust in all variants by more than 96.9%. When using increased rates of fungicides (150, 200%), the biological efficiency was 100%. The high sensitivity of the North Caucasian population of the pathogen P. hordei to the active substances of the studied fungicides has been proven. For all the studied drugs, the values of LC50 and LC95 were significantly lower in comparison with the recommended concentration in the working solution. The result obtained was due to the content of active substances in fungicides from different chemical classes with different mechanisms of action, which provided high efficiency in suppressing the development of barley brown rust and reduced the risk of resistance.

Response of photosynthetic efficiency parameters and leaf area index of alternative barley genotypes to increasing sowing density

Alternative barley genotypes can be a source of genetic variability for breeding and raw material for functional food production. The reaction of these genotypes to diverse sowing densities is unknown. The study aimed to assess the response in physiological characteristics of alternative barley genotypes Hordeum vulgare var. rimpaui and H. v. var. nigricans to increasing sowing density. In a strict field experiment, two barley genotypes and five sowing densities were tested: 250, 300, 350, 400, and 450 grains m-2. Chlorophyll fluorescence indices, relative chlorophyll content (SPAD), and leaf area index (LAI) were assessed. The interaction of the study year, genotype, and sowing density significantly shaped the physiological indices of the canopy. When rainfall was deficient, the plants reduced their leaf area but had higher SPAD and PIabs of the flag leaf. In the year with optimal rainfall, LAI increased with increasing sowing density. In the dry year, PIabs of the flag leaf in H. v. var. rimpaui was the highest at 250 grains m-2 and decreased with increasing density, and in H. v. var. nigricans, it only reduced at 450 grains m-2 A strong negative relationship was observed between LAI and SPAD, as well as between LAI and PIabs. Sowing density had a significant effect on grain yield per plant, which was related to the physiological response. However, the genotypes tested responded differently to this factor. The results may by prove for agricultural practice and scientific research, particularly in relation to the optimal sowing density of alternative barley genotypes and the identification of density-tolerant genotypes in response to varying environmental conditions.

Exploring the effects of barley (Hordeum vulgare L.) germination on chemical composition, phytic acid, and potential malt prebiotic properties

Germination is a complex process that triggers physical, chemical, and structural changes in grains, including macromolecule hydrolysis such as fiber components like β-glucans, and phenolic compound liberation, which may exhibit prebiotic effects. This work studies the impact of varied germination conditions on barley chemical composition, phytic acid content, and phenolic compound profile to obtain a potential prebiotic source. A combination of two temperatures (20 and 25°C) and times (35 and 72 h) was evaluated. Ungerminated barley and malt obtained under traditional brewing conditions (20°C for 95.5 h) were also analyzed. Bifidobacterium animalis subsp. lactis INL1 and B. lactis BB-12® were used to assess the potential prebiotic capacity. Barley germination at 25°C for shorter times (35–72 h) induced less starch, sugars, and β-glucans degradation than brewing malt. However, only brewing malt effectively reduced the content of phytic acid. Germination at 25°C produced a higher release of phenolic compounds. Malt obtained after germination at 20°C for 35 h was sufficient to produce a fermentable substrate by probiotic bacteria and did not stimulate pathogen-like strains. These results highlight the prebiotic potential of barley malt and uncover previously unexplored properties of this cereal, laying the groundwork for further investigation.

Multi-population GWAS detects robust marker associations in a newly established six-rowed winter barley breeding program.

Genome-wide association study (GWAS) is a powerful tool for identifying marker-trait associations that can accelerate breeding progress. Yet, its power is typically constrained in newly established breeding programs where large phenotypic and genotypic datasets have not yet accumulated. Expanding the dataset by inclusion of data from well-established breeding programs with many years of phenotyping and genotyping can potentially address this problem. In this study we performed single- and multi-population GWAS on heading date and lodging in four barley breeding populations with varying combinations of row-type and growth habit. Focusing on a recently established 6-rowed winter (6RW) barley population, single-population GWAS hardly resulted in any significant associations. Nevertheless, the combination of the 6RW target population with other populations in multi-population GWAS detected four and five robust candidate quantitative trait loci for heading date and lodging, respectively. Of these, three remained undetected when analysing the combined populations individually. Further, multi-population GWAS detected markers capturing a larger proportion of genetic variance in 6RW. For multi-population GWAS, we compared the findings of a univariate model (MP1) with a multivariate model (MP2). While both models surpassed single-population GWAS in power, MP2 offered a significant advantage by having more realistic assumptions while pointing towards robust marker-trait associations across populations. Additionally, comparisons of GWAS findings for MP2 and single-population GWAS allowed identification of population-specific loci. In conclusion, our study presents a promising approach to kick-start genomics-based breeding in newly established breeding populations.

A Comprehensive Analysis of the 9-Cis Epoxy Carotenoid Dioxygenase Gene Family and Their Responses to Salt Stress in Hordeum vulgare L.

Barley (Hordeum vulgare L.) is among the earliest crops to be cultivated and is also considered a crucial staple crop. Nevertheless, the negative effects of abiotic stress on both the quality and productivity of barley are significant. Nine-cis-epoxycarotenoid dioxygenases (NCEDs) are rate-limiting enzymes in plants that cleave carotenoids and produce abscisic acid (ABA). The poor utilization of barley NCEDs in stress-resistant genetic breeding is due to the lack of appropriate information about their potential function in abiotic stress. The current study revealed five NCED genes in the barley genome (HvNCED1—HvNCED5), which are distributed unevenly on barley chromosomes. The PF03055 domain is present in all HvNCEDs, and they encode 413~643 amino acids. Phylogenetic analysis showed that NCED genes were categorized into three distinct clades, confirming the homology of NCED genes between H. vulgare L., Arabidopsis thaliana L., and Oryza sativa L. Expression analysis revealed that HvNCED1 is significantly upregulated under high salt stress, indicating its potential role in enhancing salt tolerance. In contrast, HvNCED3 and HvNCED4 exhibited downregulation, suggesting a complex regulatory mechanism in response to varying salt stress levels. These findings will enhance our comprehension of the genetic composition and evolutionary development of the HvNCED gene family and provide a basis for future research on their role in response to salt-induced stress.

Assessment of the Biocontrol Efficacy of Silver Nanoparticles Synthesized by Trichoderma asperellum Against Infected Hordeum vulgare L. Germination

This study investigated the biosynthesis, statistical optimization, characterization, and biocontrol activity of silver nanoparticles (AgNPs) produced by newly isolated Trichoderma sp. The Trichoderma asperellum strain TA-3N was identified based on the ITS gene sequence, together with its phenotypic characteristics (GenBank accession number: OM321439). The color change from light yellow to brown after the incubation period indicates AgNPs biosynthesis. The UV spectrum revealed a single peak with the maximum absorption at 453 nm, indicating that T. asperellum produces AgNPs effectively. A Rotatable Central Composite Design (RCCD) was used to optimize the biosynthesis of AgNPs using the aqueous mycelial-free filtrate of T. asperellum. The optimal conditions for maximum AgNPs biosynthesis (156.02 µg/mL) were predicted theoretically using the desirability function tool and verified experimentally. The highest biosynthetic produced AgNPs by T. asperellum reached 160.3 µg/mL using AgNO3 concentration of 2 mM/mL, initial pH level of 6, incubation time of 60 h, and biomass weight of 6 g/100 mL water. SEM and TEM imaging revealed uniform spherical shape particles that varied in size between 8.17 and 17.74 nm. The synthesized AgNPs have a Zeta potential value of −9.51 mV. FTIR analysis provided insights into the surface composition of AgNPs, identifying various functional groups such as N–H, -OH, C-H, C=O, and the amide I bond in proteins. Cytotoxicity and genotoxicity assays demonstrated that AgNPs in combination with T. asperellum can mitigate the toxic effects of Fusarium oxysporum on barley. This intervention markedly enhanced cell division rates and decreased chromosomal irregularities. The results indicate that AgNPs synthesized by T. asperellum show the potential as an eco-friendly and efficient method for controlling plant diseases. Further studies are necessary to investigate their possible use in the agricultural sector.

Soil and Leaf Diagnostics of Nitrogen Content in the Cultivation of Different Varieties of Various Ecotypes of Spring Barley (&lt;i&gt;Hordeum vulgare&lt;/i&gt; L.)

The possibility of an earlier and more accurate prediction of protein accumulation in grains of different varieties of spring barley of steppe and Western European ecotypes was investigated. The experiments were conducted in the central part of the Voronezh region in the Research Institute of the Central Research Center “Kamennaya Steppe” in 2019–2021. Basically, a positive and high correlation was found between the nitrogen content in the soil and the elements of productivity, which allowed us to judge the importance of mineral nutrition for the formation of grain productivity of barley. In crops of barley varieties without the use of fertilizers in all phases of plant development, the production process, depending on the nitrogen content in the soil, was more intense than in variants with the use of fertilizers. With the use of fertilizers, the intensity of the production process decreased by 5.5% during tillering and by 25.0% during the earing phase. A fairly close positive correlation was noted between the indicators of stem length (r = 0.66–0.68), productive stem (r = 0.52–0.59) and yield (r = 0.78–0.79) with nitrogen content in the soil from the tillering phase to milk ripeness in both non-fertilized and fertilized variants. A positive correlation of nitrogen content in leaves with a mass of 1000 grains was revealed: r = 0.60, 0.50–0.70, respectively, in the experimental variants. In 2021, provided with moisture, the nitrogen content in the leaves in the fertilized version was 30.8% in steppe samples and 11.8% in western samples compared with the control. The efficiency of fertilizers in the conditions of arid 2019 was reduced to 7.1–8.1%. On average over the years, when analyzing the indicators of leaf diagnostics, the effectiveness of fertilizer application in steppe varieties was 20.3, 21.1 and 8.9% in the phases of tillering, earing, and milk ripeness, while in Western varieties it was significantly less – 10.4, 11.4 and 6.1%. The maximum effect of the use of fertilizers for the grain mass index per 1 m2 was obtained in the dry 2019: 27.0 and 34.7%, respectively, depending on the group of varieties (steppe and western). The indicators of protein content in grain and its vitreousness of steppe varieties significantly exceeded the indicators of Western varieties by years and variants of the experiment. It has been shown that the use of mineral fertilizers at a dose of N60P60K60 when sowing in arid conditions was effective for barley cultivation. This technique increased the yield and weight of 1000 grains due to the high accumulation of nitrogen in the leaves by the end of the growing season, which further contributed to an increased accumulation of protein in the grain and its vitreousness, especially in varieties of steppe origin.

Accumulation of Anthocyanin in the Aleurone of Barley Grains by Targeted Restoration of the MYC2 Gene

Blue barley grain pigmentation results from anthocyanin accumulation in the aleurone layer. Anthocyanins are known for their beneficial effects on human health. The gene encoding the MYELOCYTOMATOSIS 2 (MYC2) transcription factor is potentially responsible for the blue coloration of the aleurone. In non-pigmented barley, a single nucleotide insertion in this gene causes a frameshift mutation with a premature stop codon. It was hypothesized that restoring the MYC2 reading frame could activate anthocyanin accumulation in the aleurone. Using a targeted mutagenesis approach in the present study, the reading frame of MYC2 was restored in the non-pigmented cultivar Golden Promise. Genetic constructs harboring cas9 and gRNA expression units were developed, pre-validated in protoplasts, and then functional MYC2 alleles were generated at the plant level via Agrobacterium-mediated transformation. Anthocyanin accumulation in the aleurone layer of grains from these mutants was confirmed through microscopy and chemical analysis. The expression of anthocyanin biosynthesis genes was analyzed, revealing that the restoration of MYC2 led to increased transcript levels of F3H and ANS genes. These results confirm the critical role of the MYC2 transcription factor in the blue aleurone trait and provide a biotechnological solution for enriching barley grain with anthocyanins.

The effect of seaweed fertilisation on sulfur isotope ratios (δ34S) and grain size in barley: implications for agronomy and archaeological research

IntroductionStable sulfur isotope ratios (δ34S) in bone collagen are often employed to study the consumption of marine and freshwater fish, wetland grazing, marine foraging patterns, and the possible geographic origins of food sources. However, a recent small-scale crop experiment showed that biofertilisation with seaweed can elevate δ34S in Celtic beans by ca. 10 ‰. Consumption of this food could erroneously suggest a marine diet and therefore has important implications for the reconstruction of past diets and dietary origins. However, limited research has so far been undertaken on cereals.MethodsTo address this issue, a large-scale field trial was undertaken on the Orkney Islands, whereby bere barley (a Scottish landrace, Hordeum vulgare L.) was biofertilised with seaweed at different dosages (25 t/ha, 50 t/ha), with a mineral NPK fertiliser, and left unfertilised as a control.ResultsThe total barley biomass yield was higher and barley grains were enlarged following all fertilisation treatments compared to the control barley. Barley grain and straw from seaweed-fertilised crops had more elevated δ34S values by around 2–3 ‰ compared to unfertilised plants, while the NPK-fertilised grains and plants had δ34S values 1 ‰ lower.DiscussionThese results confirm previous hypotheses that seaweed fertilisation can elevate cereal δ34S values. The comparatively small δ34S difference between control and seaweed fertilised crops in this field trial is likely due to background elevated δ34S values in the soil (+12.7 ‰), which in turn may be due to long-term exposure to oceanic-influenced rain and sea spray and/or possible historical application of seaweed, or the underlying bedrock composition. The results of this study show that seaweed fertilisation can increase barley grain sizes and δ34S values, and thus should be considered when reconstructing land management and dietary practices in the archaeological record.

First Reported Sexual Recombination Between Pyrenophora teres Isolates from Barley and Barley Grass.

Barley grass (Hordeum leporinum), which often occurs in proximity to commercial barley (H. vulgare) cultivars, is an alternative host to Pyrenophora teres, an economically important pathogen causing net blotch in barley. This study is the first to report the sexual recombination of P. teres isolates collected from barley with those collected from barley grass. The sexual recombination between P. teres isolates from barley and barley grass was confirmed using a neighbor-net network and haploblock plots based on whole-genome sequencing of seven progeny isolates. Pathogenicity assays revealed that P. teres isolates from barley grass were not host specific and could infect both barley and barley grass, and the progeny isolates were virulent on commercially grown barley cultivars. Our results contradict previous population and pathogenicity studies of P. teres isolates obtained from barley and barley grass that have reported that the two populations are genetically distinct and host specific, suggesting that isolates collected from barley or barley grass could be two different entities. Despite the genetic divergence of P. teres isolates from barley and barley grass revealed through our phylogenomic analysis, there seems to be no complete host or reproductive separation between these populations. Therefore, there is a potential for generation of novel pathotypes through sexual recombination between P. teres isolates associated with barley and barley grass, with a risk of increased impacts on commercial barley cultivars that do not carry resistance to these pathotypes.

Lowering the carbon footprint of beer through waste breadcrumb substitution for malted barley: Life cycle assessment and experimental study

Beer is the most produced and consumed alcoholic beverage in the world, but the agricultural production of its most common ingredient, i.e. malted barley, is a significant contributor to the overall environmental footprint of beer. In addition, food wastage, particularly bread with millions of slices wasted daily, poses a waste management challenge across the globe. This study aims to address both issues through brewing beer with waste bread that would have otherwise ended up in landfill by replacing a portion of malted barley with waste bread. A sourdough pale ale was brewed at various bread percentages to understand how the inclusion of bread changed the sugar profile and fermentability of the beer. The samples were mashed at two different temperatures, 65 °C and 70 °C, to assess the impacts of mashing. It was found that the volume of alcohol produced declined with increasing bread amounts, but brewing with up to 60 wt% bread produced the same volume of alcohol as a standard beer. A life cycle assessment was performed to quantify the change in cradle to grave environmental impact for brewing beers with varying bread percentages with the view to conduct more targeted feasibility studies in the future with waste bread substitution. Significant reductions in emissions were observed as regards global warming potential, terrestrial ecotoxicity, acidification, eutrophication, ozone depletion, and abiotic depletion of fossil fuels. In particular, the global warming potential for the real-life example microbrewery studied in this work was decreased by 7.13% of the total carbon dioxide equivalent annually, demonstrating the environmental advantages of brewing beer with waste bread.

Relay Intercropping of Soybean and Winter Barley in Polish Climatic Conditions—Importance of Strip Width and Yearly Weather

Climate change and the increasing demand for food necessitate innovative agricultural methods. Relay intercropping, where one crop is sown into another already-grown crop, offers a promising alternative to traditional systems. In the 2021/22 and 2022/23 seasons, a field experiment was conducted to assess the relay intercropping of winter barley (Hordeum vulgare L. ssp. polistichon) with soybean (Glycine max (L.) Merr). This experiment took place at the Brody Experimental and Educational Station of the University of Life Sciences in Poznań, Poland. Soybean was sown into designated strips within the barley field, and both crops were cultivated simultaneously until the barley was harvested. After the barley harvest, the soybean plants continued to grow and were harvested at full maturity. The results varied between the two years of this experiment. In the first year, characterized by drought conditions, the soybean yield was completely lost, while the barley maintained a stable yield. In the second year, with more favorable weather, the yields of barley and soybean were interdependent. The use of the relay intercropping system did not increase the Land Equivalent Ratio (LER) above 1. Additionally, total protein yield remained consistent across different cultivation systems. Relay intercropping can serve as a method for protecting crop protein yields under adverse weather conditions and may offer a viable alternative for soybean cultivation in challenging climates.

Comparative RNA profiling identifies stage-specific phasiRNAs and coexpressed Argonaute genes in Bambusoideae and Pooideae species.

PhasiRNAs (phased, small interfering RNAs) play a crucial role in supporting male fertility in grasses. Earlier work in maize (Zea mays) and rice (Oryza sativa) - and subsequently many other plant species - identified premeiotic 21-nt and meiotic 24-nt phasiRNAs. More recently, a group of premeiotic 24-nt phasiRNAs was discovered in the anthers of two Pooideae species, barley (Hordeum vulgare) and bread wheat (Triticum aestivum). Whether premeiotic 24-nt phasiRNAs and other classes of reproductive phasiRNAs are conserved across Pooideae species remains unclear. We conducted comparative RNA profiling of three anther stages in six Pooideae species and one Bambusoideae species. We observed complex temporal accumulation patterns of 21-nt and 24-nt phasiRNAs in Pooideae and Bambusoideae grasses. In Bambusoideae, 21-nt phasiRNAs accumulated during meiosis, whereas 24-nt phasiRNAs were present in both premeiotic and postmeiotic stages. We identified premeiotic 24-nt phasiRNAs in all seven species examined. These phasiRNAs exhibit distinct biogenesis mechanisms and potential Argonaute effectors compared to meiotic 24-nt phasiRNAs. We show that specific Argonaute genes co-expressed with stage-specific phasiRNAs are conserved across Bambusoideae and Pooideae species. Our degradome analysis identified a set of conserved miRNA target genes across species, while 21-nt phasiRNA targets were species-specific. Cleavage of few targets was observed for 24-nt phasiRNAs. In summary, this study demonstrates that premeiotic 24-nt phasiRNAs are present across Bambusoideae and Pooideae families, and the temporal accumulation of other classes of 21-nt and 24-nt phasiRNA differs between bamboo and Pooideae species. Furthermore, targets of the three classes of phasiRNAs may be rapidly evolving or undetectable.

Field versus controlled environmental experiments to evaluate the heat stress response of barley (Hordeum vulgare L.)

The complexity of heat stress hinders both the exploration of the genetic basis of stress response and breeding of genotypes with increased stress tolerance. Our main goal was to analyze and compare the possibilities of evaluating heat stress responses of barley cultivars in field sowing and controlled environmental experiments. For this purpose, a four-year field-sown experiment was carried out at one location in a panel of 190 winter and facultative barleys. In parallel, a subset of 28 cultivars were included into controlled environmental tests, where their reactions were determined to single heat stress treatment applied at heading and to combined heat stresses applied at first node appearance and then at heading. Based on the grain-yield related parameters, seven distinct clusters of the cultivars could be established with specific reaction patterns across the years. There was one year with close to optimal weather conditions and one year, when heat stress occurred during flowering and grain setting, making it possible to evaluate the heat stress responses of the 190 barley genotypes. In the heat stress prone 2022 year, the general trends were a strong reduction in the reproductive tiller number and a slight reduction in the fertility. In several groups, these negative effects were compensated with significant increases in grain number per ears and with strong increases in the average grain weight. Under controlled conditions, heat stress significantly reduced most of the grain-yield related traits. Among the more tolerant genotypes, two basic response types could be distinguished. One group was able to better preserve the grain number and weight in the main ear under heat stress, while the other was more able to allocate resources into the side tillers during the recovery period. In the combined heat stress, the average trait values were similar to those in the single stress or even lower, and there was no general priming effect clearly detectable. In the case of the 28 genotypes, there were significant correlations between the stress-induced changes in grain-yield related traits measured under field and under controlled conditions, underlining the possibility of combining the information originating from the two different environments.