Durum Research Articles

Identification of effector genes of <i>Parastagonospora nodorum</i>, <i>P. pseudonodorum</i> in Tambov populations and sensitivity genes to NEs in varieties and hybrid lines of spring soft wheat

BACKGROUND: Parastagonospora nodorum and P. pseudonodorum are known for their ability to produce necrotrophic effectors that play an important role in micromycete pathogenicity. Fungal strains characterized by the presence of effector genes will be used to create artificial infectious backgrounds to identify sources and donors of resistance to fungal diseases. Selected varieties and lines that are donors of recessive alleles snn1 and snn3, which control plant resistance to fungal toxins PtrTox1 and PtrTox3, are recommended for inclusion in programs for breeding wheat for resistance to septoriosis pathogens. AIM: The aim of the work is to assess the populations of the fungi Parastagonospora nodorum and P. pseudonodorum in 2023 based on the presence of effector genes, as well as to identify alleles of Snn1/snn1, Snn3/snn3 genes that control the sensitivity or resistance of wheat to PtrTox1 and PtrTox3 toxins. MATERIALS AND METHODS: Infectious samples were collected in 2023 from spring wheat leaves. In addition, the material for the study was 2 varieties and 23 lines of spring soft wheat of local selection. Using the molecular markers Xfcp624 and Xcfd20, the presence of the Snn1 and Snn3-B1 alleles, which control sensitivity to the fungal toxins PtrTox1 and PtrTox3, was detected. RESULTS: Using molecular screening, ToxA and Tox1 genes were identified in genotypes of P. pseudonodorum isolates; Tox3 and Tox267 in P. nodorum isolates. 2 varieties of spring soft wheat and 11 hybrid lines carry a recessive allele snn1, which protects against the phytopathogen toxin PtrTox1; wheat variety Tambovchanka and 2 hybrid lines carry the recessive allele snn3 on chromosome B1, which confers resistance to the fungal toxin PtrTox3. CONCLUSIONS: The ToxA gene was found only among monoconidial isolates of P. pseudonodorum species obtained from leaves of spring soft wheat of Lebedushka variety. As a result of molecular screening, the Tox1 gene was identified among 70 P. pseudonodorum isolates (43,21% of those studied). The presence of the Tox3 and Tox267 genes was established in 30 isolates of P. nodorum species obtained from plant samples of spring durum wheat Donskaya Elegiya. Using the PCR method, donors of the snn1 and snn3 genes were identified.

Prospects for tritordeum (×Tritordeum martinii A. Pujadas, Nothosp. Nov.) cereal breeding: Key points for future challenges

AbstractTritordeum is the new cereal derived from crosses between the wild barley Hordeum chilense Roem. et Schultz. and either durum or bread wheat, resulting in hexaploid and octoploid tritordeums, respectively. The success of tritordeum as a crop depends on the effectiveness of its breeding programme. In this work, new advanced tritordeum lines are screened for grain carotenoid content and disease susceptibility to analyse the impact of the current breeding strategies and to identify their strengths and putative limitations for future challenges. We conclude that selection for grain carotenoid content, the main strength for the tritordeum commercialization, should be reinforced not only by using the diversity of H. chilense but also incorporating beneficial alleles from durum wheat. Furthermore, genes for stem rust resistance from the A and B wheat genomes must be incorporated into tritordeum breeding programme. Finally, when selecting for threshability, tritordeums without chromosome substitutions should be preferentially selected using a marker‐assisted selection approach.

Mapping seedling and adult plant leaf rust resistance genes in the durum wheat cultivar Strongfield and other Triticum turgidum (L.) lines.

Durum wheat (T. turgidum L.) is threatened by the appearance of new virulent races of leaf rust, caused by Puccinia triticina, in recent years. This study was conducted to determine the leaf rust resistance in a modern Canadian durum cultivar Strongfield. Six populations derived from crosses of Strongfield with six tetraploid wheat lines, respectively, were tested at seedling plant stage with different P. triticina races. Two of the populations were evaluated for adult plant leaf rust infection in Canada and Mexico. A stepwise regression joint linkage QTL mapping and analysis by MapQTL were performed. Strongfield contributed the majority of QTL detected, contributing seven QTL detected in field tests, and eight QTL conditioning seedling resistance. A 1B QTL, QLr-Spa-1B.1, from Strongfield had a significant effect in both Canadian and Mexican field tests, and corresponded with Lr46/Yr29. The remaining field QTL were found in only the Canadian or the Mexican environment, not both. The QTL from Strongfield on 3A, QLr-Spa-3A, conferred seedling resistance to all races tested and had a significant effect in the field in Canada. This is the first report of the QLr-Spa-3A and Lr46/Yr29 as key components of the genetic resistance in Canadian durum wheat. KASP markers were developed to detect the QLr-Spa-3A for use in marker assisted leaf rust resistance breeding. The susceptible parental lines contributed QTL on 1A, 2B and 5B that were effective in Mexican field tests that may be good targets to integrate into modern durum varieties to improve resistance to new durum virulent races.

Comparative Study of the Technological Potential of Durum Wheat Varieties after Natural Aging

Background: Durum wheat [Triticum turgidum L. ssp. durum (Desf.) Husn.] is one of the most essential cereal species and is cultivated worldwide over almost 17 million ha, with a global production of 38.1 million tonnes in 2019 (Ioannis et al., 2020). Cereal grains have always been the main source of food for humans and domestic animals. In Algeria, cereal products, mainly wheat, play a strategic role in the food system and the national economy. Knowledge of the phenomena governing their preservation and mastery of storage techniques are crucial to the survival of the world’s population. The world human population is increasing day by day and estimated to reach 8.0 billion by 2025 and 8.9 billion by 2050. Methods: The ideal of this work was to study the effect of natural aging on the viability and technological quality of four kinds of durum wheat, saved for two years under two storage conditions, favorable conditions in the cold room, temperature (-04°C); moisture (12%) and inimical conditions (medium), temperature estimated between 11 and 37°C and relative moisture of 30 to 85 83%. To do this, a study of morphological, physiological, biochemical and technological parameters was initiated on the seed and on the whole factory. Result: The protein content values recorded are low compared to the control under both conditions (favorable, inimical) of natural aging; the differences are veritably largely significant. A significant increase in proline situations in seeds subordinated to natural aging compared to the control. Under good natural aging conditions, we notice that the different genotypes tested record low answerable sugar contents compared to the control; whereas under inimical NA conditions, we note a significant increase in answerable sugar content; the differences are veritably largely significant. The results attained show that, in general, the kinds are more sensitive to inimical conditions of natural aging, while without favorable conditions, the effect is less drastic.

Participatory Demonstration of Durum Wheat Production Blending Vertisols Management Technologies in Lume District, East Shewa, Ethiopia

Durum wheat production on Vertisols is constrained by waterlogging, where excessive soil moisture limits nutrient availability, resulting in lower yields and higher input demand. Aybar broad bed maker (BBM) was recommended to make broad beds and furrows (BBF) and drain the excess water although it is not widely adopted by farmers. Therefore, this demonstration activity was conducted to create awareness about the importance of BBF along with the recommended fertilizer rates in Lume district during the 2021 and 2022 main cropping seasons. Nine target farmers were purposefully selected based on the ground that their farms are waterlogged Vertisols. Aybar BBM to make the BBF with an 80 cm bed and 20 cm furrow width, while recommended fertilizers at a rate of 92 kg ha<sup>-1</sup> nitrogen (N) and 10 kg ha<sup>-1 </sup>phosphorous (P) were used. The yield data and farmers’ perception were analyzed using t-test, descriptive statistics, and narration, while partial budget analysis was conducted to examine the economic feasibility of the technologies. Results showed that growing durum wheat on BBF by applying the recommended N and P rates resulted in significantly higher grain yield (3474 kg ha<sup>-1</sup>) <i>with a 65.4% yield advantage </i>compared to ridge and furrow (RF) (2100 kg ha<sup>-1</sup>) with the blanket fertilizer rates. The partial budget analysis revealed that land preparation using Aybar BBM, alongside the recommended fertilizer rates, brought a net benefit of 48,563 ETB ha<sup>-1</sup> over the farmers' practice. Likewise, the marginal rate of return for changing from the local plow to Aybar BBM is 901.7%. The farmers also witnessed that the Aybar BBM even takes less plowing time and energy, and they want to continue to use it. <i>In light of these results, the study concludes that the use of Aybar BBM and recommended N and P rates, as a production package on waterlogged Vertisols, is profitable for farmers and recommends promoting and scaling up these technologies in the study area and other waterlogged Vertisols regions of the country.</i>

Phenotypic characterization and gene mapping of hybrid necrosis in Triticum durum–Haynaldia villosa amphiploids

Key messagePhenotypical, physiological and genetic characterization was carried out on the hybrid necrosis gene from Haynaldia villosa, and the related gene Ne-V was mapped to chromosome arm 2VL.Introducing genetic variation from wild relatives into common wheat through wide crosses is a vital strategy for enriching genetic diversity and promoting wheat breeding. However, hybrid necrosis, a genetic autoimmunity syndrome, often occurs in the offspring of interspecific or intraspecific crosses, restricting both the selection of hybrid parents and the pyramiding of beneficial genes. To utilize the germplasms of Haynaldia villosa (2n = 2x = 14, VV), we conducted wide hybridization between durum wheat (2n = 4x = 28, AABB) and multiple H. villosa accessions to synthesize the amphiploids (2n = 6x = 42, AABBVV). This study revealed that 61.5% of amphiploids derived from the above crosses exhibited hybrid necrosis, with some amphiploids even dying before reaching maturity. However, the initiation time and severity of necrosis varied dramatically among the progenies, suggesting that there were multiple genetic loci or multiple alleles in the same genetic locus conferring to hybrid necrosis in H. villosa accessions. Genetic analysis was performed on the F2 and derived F2:3 populations, which were constructed between amphiploid STH59-1 with normal leaves and amphiploid STH59-2 with necrotic leaves. A semidominant hybrid necrosis-related gene, Ne-V, was mapped to an 11.8-cM genetic interval on the long arm of chromosome 2V, representing a novel genetic locus identified in Triticum-related species. In addition, the hybrid necrosis was correlated with enhanced H2O2 accumulation and cell death, and it was influenced by the temperature and light. Our findings provide a foundation for cloning the Ne-V gene and exploring its molecular mechanism.

Zinc foliar application may alleviate drought stress in wheat species through physiological changes

Drought is the greatest threat to food security in the climate change scenario, which affects crop plants' growth and development by disturbing the plant's physiological and biochemical processes. Zinc (Zn) is an essential micronutrient in many metabolic processes and may improve plant tolerance to water deficit conditions besides its nutritional value.This study investigated the reaction of several wheat species with different ploidy levels to foliar Zn application under water stress. Water stress significantly reduced grain yield (GY), leaf relative water contents (RWC), chlorophyll (Chla and Chlb), and carotenoid (Car) contents. Water stress also impacted several other physiological characteristics by increasing leaf hydrogen peroxide (HP), free proline (Prl), malondialdehyde (MDA) contents, soluble protein (PC), sodium content (Na+), and antioxidant enzymes, including peroxidase (Pox), ascorbate peroxidase (Aes) and catalase (Cat). Remarkably, the Zn application alleviated yield reduction caused by water stress. Moreover, the Zn application increased grains' Zn, potassium content (K+), and K+/Na+ ratio, RWC, Chl, Car contents, Pox, Aes, and Cat activities while significantly reducing MDA, HP, and Na+ contents compared with the control treatment. Pox, Aes, and Cat activities increased to higher concentrations in 6x and 4x than in 2x, indicating that the 6x and 4x species responded better to water stress. Wild and landrace varieties of 4x, such as T. dicoccum, T. ispahanicum, and T. dicoccoides, showed better water stress tolerance than the landrace varieties of 2x and 6x species. These species may be a valuable genetic source for improving modern bread and durum wheat to water stress.

GeCKO: user-friendly workflows for genotyping complex genomes using target enrichment capture. A use case on the large tetraploid durum wheat genome

BackgroundGenotyping of individuals plays a pivotal role in various biological analyses, with technology choice influenced by multiple factors including genomic constraints, number of targeted loci and individuals, cost considerations, and the ease of sample preparation and data processing. Target enrichment capture of specific polymorphic regions has emerged as a flexible and cost-effective genomic reduction method for genotyping, especially adapted to the case of very large genomes. However, this approach necessitates complex bioinformatics treatment to extract genotyping data from raw reads. Existing workflows predominantly cater to phylogenetic inference, leaving a gap in user-friendly tools for genotyping analysis based on capture methods. In response to these challenges, we have developed GeCKO (Genotyping Complexity Knocked-Out). To assess the effectiveness of combining target enrichment capture with GeCKO, we conducted a case study on durum wheat domestication history, involving sequencing, processing, and analyzing variants in four relevant durum wheat groups.ResultsGeCKO encompasses four distinct workflows, each designed for specific steps of genomic data processing: (i) read demultiplexing and trimming for data cleaning, (ii) read mapping to align sequences to a reference genome, (iii) variant calling to identify genetic variants, and (iv) variant filtering. Each workflow in GeCKO can be easily configured and is executable across diverse computational environments. The workflows generate comprehensive HTML reports including key summary statistics and illustrative graphs, ensuring traceable, reproducible results and facilitating straightforward quality assessment. A specific innovation within GeCKO is its 'targeted remapping' feature, specifically designed for efficient treatment of targeted enrichment capture data. This process consists of extracting reads mapped to the targeted regions, constructing a smaller sub-reference genome, and remapping the reads to this sub-reference, thereby enhancing the efficiency of subsequent steps.ConclusionsThe case study results showed the expected intra-group diversity and inter-group differentiation levels, confirming the method's effectiveness for genotyping and analyzing genetic diversity in species with complex genomes. GeCKO streamlined the data processing, significantly improving computational performance and efficiency. The targeted remapping enabled straightforward SNP calling in durum wheat, a task otherwise complicated by the species' large genome size. This illustrates its potential applications in various biological research contexts.

Effect of Na2SO4 Application on the Growth, Yield and Cd uptake of Wheat

Objective: Durum wheat accumulates more cadmium (Cd) in the grain than bread wheat. The aim of this study was to determine the effect of Na2SO4 salt on Cd uptake in wheat grain. Material and Method: The experiment was conducted by using durum wheat cultivar (Triticum durum, cvs. Balcalı-2000) under greenhouse condition. After 43 day of growth in the greenhouse, the shoots were harvested and dried at 70 ºC for determination of shoot dry matter production. It was also analyzed Cd concentration in shoot. The concentration of shoot Cd was measured by (ICP-OES, Varian, Australia). Results: Our results conclude that soil salinity increases Cd accumulation in the shoot even when soil Cd rates are very low. Furthermore, salinity in Cd-contaminated soils may accelerate cadmium transport to the shoot. Conclusions: The findings of this study revealed that shoot Cd concentration increased with increasing applied Cd and Na2SO4 rates.

The Combined ICP-MS, ESEM-EDX, and HAADF-STEM-EDX Approach for the Assessment of Metal Sub-Micro- and Nanoparticles in Wheat Grain.

Metal sub-microparticles (SMPs) and nanoparticles (NPs) presence in food is attributable to increasing pollution from the environment in raw materials and finished products. In the present study, a multifaceted analytical strategy based on Environmental Scanning Electron Microscopy and High-Angle Annular Dark-Field-Scanning Transmission Electron Microscopy coupled with Energy-Dispersive X-ray Spectroscopy (ESEM-EDX, HAADF-STEM-EDX) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was proposed for the detection and characterization of metal and metal-containing SMPs and NPs in durum wheat samples, covering a size measurement range from 1 nm to multiple µm. ESEM-EDX and ICP-MS techniques were applied for the assessment of SMP and NP contamination on the surface of wheat grains collected from seven geographical areas characterized by different natural and anthropic conditions, namely Italy, the USA, Australia, Slovakia, Mexico, Austria, and Russia. ICP-MS showed significant differences among the mean concentration levels of metals, with the USA and Italy having the highest level. ESEM-EDX analysis confirmed ICP-MS concentration measurements and measured the highest presence of particles < 0.8 µm in size in samples from Italy, followed by the USA. Less marked differences were observed when particles < 0.15 µm were considered. HAADF-STEM-EDX was applied to a selected number of samples for a preliminary assessment of internal contamination by metal SMPs and NPs, and to expand the measurable particle size range. The multifaceted approach provided similar results for Fe-containing SMPs and NPs. ICP-MS and ESEM-EDX also highlighted the presence of a significant abundance of Ti- and Al-containing particles, while for STEM-EDX, sample preparation artifacts complicated the interpretation. Finally, HAADF-STEM-EDX results provided relevant information about particles in the low nm range, since, by applying this technique, no particles smaller than 50 nm were observed in accordance with ESEM-EDX.

Mapping nutrient and soil fertility indexes for Durum Wheat in the La Mina region of Algeria

The growing population coupled with a reduction in available agricultural land per capita necessitates smart management practices to boost production per unit area and enhance overall land productivity, ultimately ensuring food security. Thus, evaluating soil fertility and productivity is crucial for sustainable agriculture. This study aims to assess the chemical fertility status of the soils within the irrigated perimeter of la Mina, a region in Algeria known for Durum Wheat production. Thirty-two soil samples were collected from the study area and subjected to analysis for total N, available P and K, and organic matter (OM) concentration. All the soils were basic (pH 7.63–8.95), had low concentrations of total N (0.04 and 0.19 %), low concentrations of available P (7.36 – 30 mg kg−1), low concentrations of available K (<0.4 Cmol kg−1) and low concentrations of OM (0.67–2.37 % by weight). Using a Nutrient Index classification, the overall classification of the soils of the irrigated perimeter of la Mina were low for N, P, K and OM. In addition, the Soil Fertility Index revealed three levels of fertility with a dominance of fertility level 5 (low). Application of the FertiliCalc software for the evaluation of nutrient requirements of Durum Wheat showed average requirements of 183 kg ha−1 for N, 65.8 kg ha−1 for P and 579 kg ha−1 for K. In light of these findings, appropriate agricultural practices, including the addition of fertilizers, are required to build and maintain the needs of Durum Wheat in the study area.

Seminal root angle is associated with root system architecture in durum wheat

AbstractOptimal root system architecture (RSA) is critical for efficient resource capture in soils, hence being an interest in crop breeding. Seminal root angle (SRA) at the seedling stage in durum wheat has been suggested to be a good indicator of RSA. However, research on correlating such laboratory‐based seedling root phenotyping to RSA at later phases of plant growth is limited, resulting in the importance of root trait variation seen in seedlings often being overstated. To explore the role of SRA in modifying RSA at later phases of plant growth, we assessed 11 genotypes contrasting in SRA (wide and narrow), grown in a rhizobox designed for phenotyping root systems of plants during late‐tillering. Aboveground traits and root dry mass in different soil depths and across the entire soil volume were measured manually, while root architectural traits were extracted using image analysis and summarised by multiple factor analysis to describe RSA. When comparing the wide and narrow genotypes, no differences were detected for aboveground traits and total root dry mass. However, differences were observed in the allocation of root dry mass at different depths. The wide and narrow genotypes showed distinct RSAs, particularly in the upper soil (0–30 cm). The wide genotypes exhibited a ‘spread‐out’ root system with dense and thin roots, whereas the narrow genotypes had a compact root system with fewer but thicker roots. Our study demonstrated a clear difference in RSA between the wide and narrow genotypes, highlighting the association between SRA on the direction and distribution of root growth in plants at later growth stages.

Lipids and Fatty Acid Composition Reveal Differences between Durum Wheat Landraces and Modern Cultivars.

Durum wheat (Triticum turgidum L. ssp. durum) landraces, traditional local varieties representing an intermediate stage in domestication, are gaining attention due to their high genetic variability and performance in challenging environments. While major kernel metabolites have been examined, limited research has been conducted on minor bioactive components like lipids, despite their nutritional benefits. To address this, we analyzed twenty-two tetraploid accessions, comprising modern elite cultivars and landraces, to (i) verify if the selection process for yield-related traits carried out during the Green Revolution has influenced lipid amount and composition; (ii) uncover the extent of lipid compositional variability, giving evidence that lipid fingerprinting effectively identifies evolutionary signatures; and (iii) identify genotypes interesting for breeding programs to improve yield and nutrition. Interestingly, total fat did not correlate with kernel weight, indicating lipid composition as a promising trait for selection. Tri- and di-acylglycerol were the major lipid components along with free fatty acids, and their relative content varied significantly among genotypes. In particular, landraces belonging to T. turanicum and carthlicum ecotypes differed significantly in total lipid and fatty acid profiles. Our findings provide evidence that landraces can be a genetically relevant source of lipid variability, with potential to be exploited for improving wheat nutritional quality.

Is the CslF6 gene involved in the accumulation of (1,3;1,4)-β-D-glucan in wheats, their wild relatives and their hybrids?

Mixed linkage (1,3;1,4)-β-d-glucan (MLG) is a well-recognized bioactive carbohydrate and dietary fibre with expanding applications in food industry. The MLG are small components of the cell wall of vegetative tissues of cereals synthetized by members of the Cellulose Synthase-Like genes (Csl). Within the family, the CslF6 has been the major contributor in wheat. It is of significant health and economic benefits to enhance MLG content in wheat, a staple grain with naturally low MLG levels. This study investigated the role of CslF6 gene in MLG synthesis and analysed total MLG contents, cell wall monosaccharide, glycosidic linkage composition, and profile of major comprising oligosaccharides of MLG in various wheat genotypes, their wild relatives (Aegilops caudata and Dasypyrum villosum), and hybrids between them. We observed a relationship between CslF6 gene expression and MLG accumulation across the different wheat lines. While Aegilops caudata and Dasypyrum villosum exhibited higher MLG content than other genotypes, hybrid breeding led to an increase in MLG content by 24.4% in durum wheat and 43.3% in T. aestivum. Variations in the ratios of major oligosaccharides released from MLG by lichenase treatment and in the compositions of cell wall monosaccharides and glycosidic linkages were also found. This study demonstrates that HPAEC-PAD and GC–MS-based glycomics are invaluable tools to assist breeders in selecting high MLG lines.

Potential for and impacts of mainstreaming diversification crops through institutional catering

IntroductionIn France, land use is dominated by a narrow range of crops. As crop diversification is increasingly promoted to transform the food system, outlets for diversification crops need to be identified. We assess the scope for introducing diversification crops from farmers’ fields to canteen plates, and the agroecological, environmental, work-related and nutritional impacts of their introduction.MethodsWe focus on three diversification crops: chickpea, squash, and millet, to partly replace soft wheat, potato, and durum wheat, respectively. For each crop, we define three scenarios of low (1), medium (2) and high (3) integration into institutional catering on a national scale. We assess the scenarios against the amount of diversification cropland area needed and their expected impacts.ResultsDiversification crops can be developed through institutional catering. Taking the case of chickpea, in Scenario 1, chickpea flour is introduced in a cake served once every 20 days, replacing 30% of the soft wheat flour used. This amounts to 874 ha cropped. In Scenario 2, chickpea flour partly replaces wheat flour in all preparations, and 4,048 ha are required. In Scenario 3, raw chickpeas are also introduced into new recipes and 20,958 ha are needed. All three diversification crops support the establishment of agroecological cropping systems, with enhanced nutrient cycling in particular, and reduce their environmental footprint, notably by avoiding pesticide use. Diversification crops do not generate work constraints for farmers and cooks. However, they have a lower productivity per unit area than the reference crops, although they do improve several nutrition parameters such as fiber intake.DiscussionWe show for the first time that institutional catering provides a tangible outlet for developing diversification crops and improving the sustainability of agriculture. Our scenarios can support concerted actions between farmers, supply-chain actors, cooks and policy makers, as well as communication to eaters surrounding their impacts on agriculture.

Response of immature and mature embryos of modern Egyptian commercial durum (Triticum durum Desf.) and bread wheat (Triticum aestivum L.) for in Vitro culture

Response of immature and mature embryos of modern Egyptian commercial durum (Triticum durum Desf.) and bread wheat (Triticum aestivum L.) for in Vitro culture

Wheat dwarfing reshapes plant and fungal development in arbuscular mycorrhizal symbiosis.

The introduction of Reduced height (Rht) dwarfing genes into elite wheat varieties has contributed to enhanced yield gain in high input agrosystems by preventing lodging. Yet, how modern selection for dwarfing has affected symbiosis remains poorly documented. In this study, we evaluated the response of both the plant and the arbuscular mycorrhizal fungus to plant genetic variation at a major Quantitative Trait Locus called QTL 4B2, known to harbor a Rht dwarfing gene, when forming the symbiosis. We used twelve inbred genotypes derived from a diversity base broadened durum wheat Evolutionary Pre-breeding Population and genotyped with a high-throughput Single Nucleotide Polymorphism (SNP) genotyping array. In a microcosm setup segregating roots and the extra-radical mycelium, each wheat genotype was grown with or without the presence of Rhizophagus irregularis. To characterize arbuscular mycorrhizal symbiosis, we assessed hyphal density, root colonization, spore production, and plant biomass. Additionally, we split the variation of these variables due either to genotypes or to the Rht dwarfing genes alone. The fungus exhibited greater development in the roots of Dwarf plants compared to non-Dwarf plants, showing increases of 27%, 37% and 51% in root colonization, arbuscules, and vesicles, respectively. In addition, the biomass of the extra-radical fungal structures increased by around 31% in Dwarf plants. The biomass of plant roots decreased by about 43% in mycorrhizal Dwarf plants. Interestingly, extraradical hyphal production was found to be partly genetically determined with no significant effect of Rht, as for plant biomasses. In contrast, variations in root colonization, arbuscules and extraradical spore production were explained by Rht dwarfing genes. Finally, when mycorrhizal, Dwarf plants had significantly lower total P content, pointing towards a less beneficial symbiosis for the plant and increased profit for the fungus. These results highlight the effect of Rht dwarfing genes on both root and fungal development. This calls for further research into the molecular mechanisms governing these effects, as well as changes in plant physiology, and their implications for fostering arbuscular mycorrhizal symbiosis in sustainable agrosystems.

Fusarium species causing head blight in wheat and barley show no vertical races

On a global scale, Fusarium head blight (FHB) is one of the most noxious diseases of wheat and barley. One or two Fusarium species out of 17 pathogens implicated in the complex FHB disease do not have vertical races following infection in bread wheat; however, no reports support this observation in durum wheat and barley. To end this, 16 fungal isolates of varying aggressiveness of four Fusarium species were tested on eight bread and durum wheat and barley cultivars covering a wide range from moderate resistance to susceptibility. Nine pathogenic components obtained under in vitro, growth chamber and field conditions were measured to determine whether true vertical races exist within the four tested Fusarium species. Although combined analysis of bio-experiments showed that isolate × cultivar interactions were significant, this relationship was unstable over experiments. However, the tested three bread wheat, three durum wheat and two barley cultivars showed consistent resistance to fungal isolates within each tested species, showing that F. culmorum, F. solani, F. verticillioides, and F. equiseti do not have vertical races. Our data concluded that the resistance to FHB in wheat and barley was of the horizontal and non-species specific type. There was no signal for any vertical genes in all tested Fusarium species. Consequently, the resistance genes in sources presently employed in breeding programs are not expected to succumb to new FHB races in the near future. To our best knowledge, this is the first report to show the absence of vertical Fusarium races upon infection durum wheat and barley, and is harmony with earlier reports conduced with bread wheat infected with F. graminearum and F. culmorum.

Examine the Effects of Inter Row Spacing, Weeding Frequency and Weed Infestation on Agro Morphological Traits and Yield of Durum Wheat (Triticuma Durum Desf.) Variety in Bedesa, Oromia, Ethiopia

According to study, durum wheat (Triticum durum Desf.), is an important food crop in the world, with an estimated annual production of 36 million tons. Randomized complete block design was employed. With a relative density 74.6%, broadleaved weed species were the most dominant followed by grasses with relative density of 24.3%. Number of tillers per plant, plant height, Grains per spike, aboveground biomass yield, and grain yield were affected by the interaction of weeding frequency and spacing. Spacing and Weeding frequency were significantly affected days to heading, spike length, thousand grain weight and harvest index. Wider spacing, four wedding and control weeding frequencies had significantly yield components of durum wheat. Highest dry biomass weight was achieved by treatments with 10 cm row spacing for both grass and wide weed species. As study sowing durum wheat with 30 cm row spacing and keeping it completely weed free resulted in optimum growth and grain yield.

Induction of oxidative stress in a variety of durum wheat (Triticum durum Desf) exposed to recommended doses of pesticides

The objective of this study was to assess the toxicity of two pesticides (Prosaro® XRT and Decis® EC 25) widely used in the agricultural region of El-Tarf located in northeastern Algeria, as well as their combinations on a variety of durum wheat “Triticum durum Desf”. The toxicity of these products was evaluated using physiological (chlorophyll) and biochemical parameters (proteins, glutathione, catalase activity and glutathione S-transferase, acetylcholine esterase, lipoxygenase). The recommended dose and its double were tested individually and in combination for this. It should be noted that the protocol used and the initial concentrations selected are the same as those used in the field. After D7 and D14 of exposure, all dosages were administered. The results obtained revealed a decrease in chlorophyll contents and Glutathione levels as well as an induction of total proteins and the different enzymatic activity (catalase, glutathione S-transferase, lipooxygenase) and this for the two root and leaf compartments. Thus, it turns out that the concentrations used in open fields are not harmful to the plant but generate free radicals which are taken care of by the latter’s defense system, thus allowing it to tolerate these stress conditions. Keywords: toxicity, pesticides, Triticum durum, oxidative stress, stress biomarkers