Wheat Cultivars Research Articles

Heat stress during male meiosis impairs cytoskeletal organization, spindle assembly and tapetum degeneration in wheat.

The significance of heat stress in agriculture is ever-increasing with the progress of global climate changes. Due to a negative effect on the yield of staple crops, including wheat, the impairment of plant reproductive development triggered by high ambient temperature became a restraint in food production. Although the heat sensitivity of male meiosis and the following gamete development in wheat has long been recognized, a detailed structural characterization combined with a comprehensive gene expression analysis has not been done about this phenomenon. We demonstrate here that heat stress severely alters the cytoskeletal configuration, triggers the failure of meiotic division in wheat. Moreover, it changes the expression of genes related to gamete development in male meiocytes and the tapetum layer in a genotype-dependent manner. 'Ellvis', a heat-tolerant winter wheat cultivar, showed high spikelet fertility rate and only scarce structural aberrations upon exposure to high temperature. In addition, heat shock genes and genes involved in scavenging reactive oxygen species were significantly upregulated in 'Ellvis', and the expression of meiosis-specific and major developmental genes showed high stability in this cultivar. In the heat-sensitive 'Mv 17-09', however, genes participating in cytoskeletal fiber nucleation, the spindle assembly checkpoint genes, and tapetum-specific developmental regulators were downregulated. These alterations may be related to the decreased cytoskeleton content, frequent micronuclei formation, and the erroneous persistence of the tapetum layer observed in the sensitive genotype. Our results suggest that understanding the heat-sensitive regulation of these gene functions would be an essential contribution to the development of new, heat-tolerant cultivars.

Dual RNA-sequencing of Fusarium head blight resistance in winter wheat.

Fusarium head blight (FHB) is a devastating fungal disease responsible for significant yield losses in wheat and other cereal crops across the globe. FHB infection of wheat spikes results in grain contamination with mycotoxins, reducing both grain quality and yield. Breeding strategies have resulted in the production of FHB-resistant cultivars, however, the underlying molecular mechanisms of resistance in the majority of these cultivars are still poorly understood. To improve our understanding of FHB-resistance, we performed a transcriptomic analysis of FHB-resistant AC Emerson, FHB-moderately resistant AC Morley, and FHB-susceptible CDC Falcon in response to Fusarium graminearum. Wheat spikelets located directly below the point of inoculation were collected at 7-days post inoculation (dpi), where dual RNA-sequencing was performed to explore differential expression patterns between wheat cultivars in addition to the challenging pathogen. Differential expression analysis revealed distinct defense responses within FHB-resistant cultivars including the enrichment of physical defense through the lignin biosynthesis pathway, and DON detoxification through the activity of UDP-glycosyltransferases. Nucleotide sequence variants were also identified broadly between these cultivars with several variants being identified within differentially expressed putative defense genes. Further, F. graminearum demonstrated differential expression of mycotoxin biosynthesis pathways during infection, leading to the identification of putative pathogenicity factors.

Assessing genetic diversity of indigenous bread and durum wheat cultivars in Iran using inter simple sequence repeat (ISSR) markers

Assessing genetic diversity of indigenous bread and durum wheat cultivars in Iran using inter simple sequence repeat (ISSR) markers

Selenium biofortification impacts nutritional composition and storage proteins in wheat grains

Selenium (Se) biofortification of staple crops can be used as a valuable pathway to prevent Se deficiency in human diet. In this study, a pot experiment was performed under semi-controlled conditions to investigate the response of indigenous wheat cultivars to different Se concentrations (0 to 100 mg L-1) and to also assess the effects of Se foliar application on the storage proteins in wheat grains. A linear increase in Se concentrations in the grains of various wheat cultivars was observed (up to 158 μg kg-1) in response to Se application rates. It was observed that Gandum-1, Fakhar-e-Bhakkar-17, Ujala-16 and Anaj-17 were the most responsive wheat cultivars to Se application rates and accumulated the highest Se concentrations in grains. Though Se foliar treatments did not significantly affect the wheat yield, a highly significant correlation was observed between the Se application rates and the concentration of mineral nutrients (iron, zinc, calcium and potassium). Moreover, the exogenous Se supply considerably enhanced the concentrations of different storage proteins viz. albumin, globulin, prolamin and glutelin in wheat grains. The target hazard quotient of all Se application rates was found less than the toxic levels. In conclusion, wheat cultivars differ in their ability to accumulate Se concentrations in grains and biofortifying the most responsive wheat cultivars could be used as an efficient agronomic strategy to overcome widespread Se deficiency in human population.

Effects of arbuscular mycorrhizal fungi on uptake, partitioning and use efficiency of nitrogen in wheat

Arbuscular mycorrhizal fungi (AMF) can promote the growth and yield of crops by increasing the use of nutrients. However, the influence of AMF on the uptake, utilization and partitioning of nitrogen (N) from different sources remain uncertain. Therefore, we investigated AMF inoculation on plant biomass, N-uptake (from fertilizers and soil), -partitioning and N use-efficiency (NUE) in two wheat cultivars using 15N isotope labeling in a field and pot experiment. Results showed that AMF inoculation increased both plant biomass and N accumulation, and altered N partitioning in wheat. AMF inoculation significantly increased root N concentration and decreased grain N concentration (GNC) and leaf N concentration. The decrease in GNC by the AMF was mainly attributed to the variations in pre-anthesis accumulated N in vegetative organs and a reduction in the amount of N translocation. AMF significantly increased root dry weight by 13.5–18.2%, N uptake of the root by 25.4–37.2%. The N partitioning ratio in roots increased, but decreased in grains. Further, AMF significantly increased plant uptake of top-dressed 15N-labeled fertilizer by 15.0–17.8%. AMF promoted grain N absorbed from fertilizer (basal and topdressing fertilizer) but reduced its uptake from soil. Importantly, fertilizer N recovery efficiency (FNRE), N utilization efficiency (NUtE) and NUE were higher in AMF than in the control (CK), demonstrating the benefits of AMF inoculation on growth in wheat. Therefore, using AMF as biofertilizers in field conditions may be an effective agronomic practice in order to ensure sustainable production.

Proline-mediated redox regulation in wheat for mitigating nickel-induced stress and soil decontamination

Nickel (Ni) is known as a plant micronutrient and serves as a component of many significant enzymes, however, it can be extremely toxic to plants when present in excess concentration. Scientists are looking for natural compounds that can influence the development processes of plants. Therefore, it was decided to use proline as a protective agent against Ni toxicity. Proline (Pro) is a popularly known osmoprotectant to regulate the biomass and developmental processes of plants under a variety of environmental stresses, but its role in the modulation of Ni-induced toxicity in wheat is very little explored. This investigation indicated the role of exogenously applied proline (10 mM) on two wheat varieties (V1 = Punjab-11, V2 = Ghazi-11) exposed to Ni (100 mg/kg) stress. Proline mediated a positive rejoinder on morphological, photosynthetic indices, antioxidant enzymes, oxidative stress markers, ion uptake were analyzed with and without Ni stress. Proline alone and in combination with Ni improved the growth, photosynthetic performance, and antioxidant capacity of wheat plants. However, Ni application alone exhibited strong oxidative damage through increased H2O2 (V1 = 28.96, V2 = 55.20) accumulation, lipid peroxidation (V1 = 26.09, V2 = 38.26%), and reduced translocation of macronutrients from root to shoot. Application of Pro to Ni-stressed wheat plants enhanced actions of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and total soluble protein (TSP) contents by 45.70, 44.06, 43.40, and 25.11% in V1, and 39.32, 46.46, 42.22, 55.29% in V2, compared to control plants. The upregulation of antioxidant enzymes, proline accumulation, and uptake of essential mineral ions has maintained the equilibrium of Ni in both wheat cultivars, indicating Ni detoxification. This trial insight into an awareness that foliar application of proline can be utilized as a potent biochemical method in mitigating Ni-induced stress and might serve as a strong remedial technique for the decontamination of polluted soil particularly with metals.

Genome-wide association study of common resistance to rust species in tetraploid wheat.

Rusts of the genus Puccinia are wheat pathogens. Stem (black; Sr), leaf (brown; Lr), and stripe (yellow; Yr) rust, caused by Puccinia graminis f. sp. tritici (Pgt), Puccinia triticina (Pt), and Puccinia striiformis f. sp. tritici (Pst), can occur singularly or in mixed infections and pose a threat to wheat production globally in terms of the wide dispersal of their urediniospores. The development of durable resistant cultivars is the most sustainable method for controlling them. Many resistance genes have been identified, characterized, genetically mapped, and cloned; several quantitative trait loci (QTLs) for resistance have also been described. However, few studies have considered resistance to all three rust pathogens in a given germplasm. A genome-wide association study (GWAS) was carried out to identify loci associated with resistance to the three rusts in a collection of 230 inbred lines of tetraploid wheat (128 of which were Triticum turgidum ssp. durum) genotyped with SNPs. The wheat panel was phenotyped in the field and subjected to growth chamber experiments across different countries (USA, Mexico, Morocco, Italy, and Spain); then, a mixed linear model (MLM) GWAS was performed. In total, 9, 34, and 5 QTLs were identified in the A and B genomes for resistance to Pgt, Pt, and Pst, respectively, at both the seedling and adult plant stages. Only one QTL on chromosome 4A was found to be effective against all three rusts at the seedling stage. Six QTLs conferring resistance to two rust species at the adult plant stage were mapped: three on chromosome 1B and one each on 5B, 7A, and 7B. Fifteen QTLs conferring seedling resistance to two rusts were mapped: five on chromosome 2B, three on 7B, two each on 5B and 6A, and one each on 1B, 2A, and 7A. Most of the QTLs identified were specific for a single rust species or race of a species. Candidate genes were identified within the confidence intervals of a QTL conferring resistance against at least two rust species by using the annotations of the durum (cv. 'Svevo') and wild emmer wheat ('Zavitan') reference genomes. The 22 identified loci conferring resistance to two or three rust species may be useful for breeding new and potentially durable resistant wheat cultivars.

Enhancing Wheat Crop Resilience to Drought Stress through Cellulolytic Microbe-Enriched Cow Dung Vermicompost.

Wheat, an important cereal crop, is commonly cultivated in arid and semiarid areas, and therefore, it often experiences water deficit conditions. The consequences of induced stress on wheat can be mitigated through vermicompost amendments. To address drought stress on wheat seedlings, a pot experiment was conducted in the wire-house in which two contrasting wheat cultivars, Faisalabad-08 (drought-tolerant) and Galaxy-13 (drought-sensitive), were exposed to three water level conditions: well-watered [D0, 70% of field capacity (FC)], moderate drought (D1, 45% FC), and severe drought (D2, 30% FC). Four rates of vermicompost, derived from cow dung enriched with cellulolytic microbes, were applied (VT0, control; VT1, 4 t ha-1; VT2, 6 t ha-1; and VT3, 8 t ha-1) to the experiment. Data on various physiological, biochemical, and enzymatic antioxidants were recorded. Our results demonstrated that the drought treatments significantly reduced nutrient accumulation, chlorophyll and SPAD values, and carotenoid content in both cultivars where the maximum reduction was recorded for severe drought stress. Nonetheless, the application of vermicompost significantly improved these traits, and statistically maximum chlorophyll contents, SPAD value, and total carotenoid contents were observed for VT1 in both cultivars under drought treatments. While the lowest chlorophyll and carotenoid contents were recorded for untreated replicated pots. Among the cultivars, Faisalabad-08 exhibited greater resistance to drought, as evidenced by higher values of the aforementioned traits compared to Galaxy-13. Soil-applied vermicompost also showed a positive influence on antioxidant enzyme activities in both wheat cultivars grown under well-watered as well as water-scarce conditions. The findings of this study revealed that drought conditions substantially decreased the enzymatic antioxidants and physiological and biochemical attributes of the wheat crop. However, soil-applied vermicompost, particularly at an optimum rate, had a positive impact on the wheat seedlings under drought conditions. Moving forward, exploring the potential of utilizing cellulolytic microbe-enriched cow dung vermicompost stands as a promising avenue to mitigate the detrimental effects of water stress on wheat. Further research in this direction could offer substantial insights into enhancing wheat resilience and productivity under water stress conditions.

A Combination of Three Genomic Regions Conditions High Level of Adult Plant Stripe Rust Resistance in Australian Wheat Cultivar Sentinel.

A seedling susceptible Australian common wheat cultivar Sentinel showed resistance to stripe rust under field conditions. A Sentinel/Nyabing3 (Nyb3)-derived recombinant inbred line (RIL) population was phenotyped. A DArTseq marker-based linkage map of the Sentinel/Nyb3 RIL population was used to determine the chromosomal location of the adult plant stripe rust resistance possessed by Sentinel. Three consistent quantitative trait loci (QTL); QYr.sun-1BL, QYr.sun-2AS and QYr.sun-3BS were detected, and they on an average explained 18%, 15.6% and 10.6% of the variation in stripe rust response, respectively. All three QTL were contributed by Sentinel. QYr.sun-1B corresponded to the previously characterized gene Yr29. Sentinel expressed resistance at the four-leaf stage at 21 ± 2 °C in the greenhouse. Monogenic segregation among the RIL population was observed when screened at the four-leaf stage at 21 ± 2 °C in the greenhouse, and the underlying resistance locus was temporarily named YrSen. QYr.sun-3BS peaked on YrSen. QYr.sun-2AS was mendelized by generating and phenotyping a mongenically sgregating F6 RIL population, and it was temporarily designated YrSen2. RILs carrying Yr29, YrSen and YrSen2 in combination exhibited responses like the parent Sentinel. Based on a comparison of the genomic locations and resistance expression with stripe rust resistance genes previously located in their respective chromosomes, QYr.sun-2AS (YrSen2) and QYr.sun-3BS (YrSen) were concluded to represent new loci.

Variation of Fusarium Head Blight Attack in Semidwarf Wheat Cultivars and Relationship with Stripe Rust Attack

Fusarium head blight (FHB) is a major threat to wheat production worldwide. We studied the Type 2 resistance of nineteen winter wheat cultivars under artificial inoculation by injecting spores of two Fusarium isolates into central florets of spikes. Weather conditions and Fusarium isolates used for artificial inoculations strongly influenced Fusarium attacks, but we also observed significant differences between cultivars. Six semidwarf wheat cultivars carrying Rht-B1b allele had significantly lower average Area Under Disease Progress Curve (AUDPC) than other cultivars, including two taller cultivars. Three of the six best resistant wheat cultivars carried the 1A-1R translocation, suggesting a beneficial effect of this rye chromatin presence on reducing the Fusarium head blight attack. Presence of stripe rust attacks significantly increased the area under disease development curve for Fusarium head blight, demonstrating the importance of debilitating effects of other biotic stresses.

Physiological and molecular responses of a resistant and susceptible wheat cultivar to the fungal wheat pathogen Zymoseptoria tritici.

Zymoseptoria tritici is the causal agent of Septoria tritici blotch (STB), one of the most economically destructive wheat foliar diseases. In this study, we explore the physiological and molecular changes elicited in two wheat cultivars with divergent responses (Taichung 29 = susceptible, and Shafir = resistant) upon infection by Z. tritici. Our aim is to uncover novel insights into the intricate mechanisms that govern wheat defense against Z. tritici infection. Our quantitative histopathological study showed that H2O2 accumulated in the resistant cultivar to a higher degree compared to the susceptible cultivar at the biotrophic and switching phase. Additionally, we combined qPCR with a targeted quantitative HPLC technique to evaluate the expression profiles of 13 defense-related genes and profile the polyphenolic compounds induced differentially in the STB susceptible and resistant cultivar. Our finding indicated that five out of 13 genes were strongly up-regulated in the resistant cultivar compared with that of the susceptible one at eight days post-inoculation (dpi), corresponding to the transition phase present in the infection process of Z. tritici. Finally, our targeted HPLC analysis demonstrated that the traced phenolic compounds were highly elevated in the susceptible cultivar infected by Z. tritici compared with that of the resistant cultivar. In conclusion, our comprehensive analysis unveils a robust defense response in the resistant wheat cultivar Shafir, characterized by heightened H2O2 accumulation, significant up-regulation of key defense-related genes during the transition phase, and a distinct profile of polyphenolic compounds, shedding light on the intricate mechanisms contributing to its resistance against Z. tritici, thereby providing valuable insights for the development of more resilient wheat varieties.

Correlação entre resistência à brusone em cultivares de trigo e taxa de esporulação de conídios de Pyricularia oryzae Triticum

ABSTRACT: The use of resistant wheat cultivars is a fundamental strategy to minimize the damages caused by blast, a disease caused by the fungus Pyricularia oryzae Triticum (PoT). The objetive of this stydy was to (a) evaluate the reaction to blast of Brazilian wheat cultivars and (b) determine whether there is correlation between severity of symptoms on wheat spikes and “sporulation rate of PoT conidia per gram of wheat spike rachis” (Rscon). Plants of 16 wheat cultivars were grown in greenhouse until flowering (Zadoks stage 65), when their spikes were inoculated with a suspension formed by mixing the conidia of three PoT isolates. The evaluated variables were blast severity on spikes at 5, 7 and 11 days after inoculation (dai) and Rscon. Rachis were evaluated individually to determine the Rscon. Correlation analyzes were carried out between blast severity means on spikes of cultivars at 5, 7 and 11 dai and Rscon. The cultivars TBIO Mestre, TBIO Aton, ORS 1401, ORS 1403, ORS Destak, ORS Feroz, and CD 116 stood out for being classified in the statistical groups with the highest resistance to blast for the four variables considered in the study. The correlation between blast severity on spikes at 5, 7 and 11 dai and Rscon is at most moderate.

Characterization of wheat genotypes for PEG-induced physiological drought stress at seedling stage

Abiotic stresses like drought frequently reduce the productivity of wheat, an important global cereal crop farmed for food, feed and raw materials. Therefore, attempt should be made to search for drought tolerance in wheat cultivars. The purpose of the study was to look into how morphological features thirty wheat genotypes were affected by PEG-induced physiological drought stress at germination and seedling stages. Seven morphological traits viz germination percentage, root number, shoot length, shoot fresh weight, root fresh weight, shoot dry weight, root dry weight was measured at 14 days of stress condition and significant variation was observed in most of the traits due to genotypes, treatments, and genotype × treatment interaction. Drought stress causes a significant decrease in almost all morphological traits during the germination and early seedling stages, and among the genotypes SA-2 and SA-3 were performed best. A positive significant correlation was found among the morphological traits, except for fresh and dry weight of shoot. Principle Component Analysis (PCA) showed that only first two PCs were significant and had eigenvalues > 1. The first two PCs cover the 72.78% of total variation. Multi Trait Stability Index (MTSI) showed that SA-3, SA-2, BL-1020 and PV-79 performed well in drought stress condition and these genotypes can be further used for breeding program to develop drought tolerant high yielding wheat variety.

QTL Mapping for Adult-Plant Resistance to Leaf Rust in Italian Wheat Cultivar Libellula.

Wheat leaf rust (Lr), which is caused by Puccinia triticina Eriks. (Pt), is one of the most important wheat diseases affecting wheat production globally. Using resistant wheat cultivars is the most economical and environmentally friendly way to control leaf rust. The Italian wheat cultivar Libellula has demonstrated good resistance to Lr in field studies. To identify the genetic basis of Lr resistance in 'Libellula', 248 F6 recombinant inbred lines from the cross 'Libellula'/'Huixianhong' was phenotyped for Lr severity in seven environments: the 2014/2015, 2016/2017, 2017/2018, and 2018/2019 cropping seasons at Baoding, Hebei Province, and the 2016/2017, 2017/2018, and 2018/2019 crop seasons at Zhoukou, Henan Province. Bulked segregant analysis and simple sequence repeat markers were then used to identify the quantitative trait loci (QTLs) for Lr adult-plant resistance in the population. Six QTLs were consequently detected and designated as QLr.hebau-1AL and QLr.hebau-1AS that were presumed to be new and QLr.hebau-1BL, QLr.hebau-3AL, QLr.hebau-4BL, and QLr.hebau-7DS that were identified at similar physical positions as previously reported QTLs. Based on chromosome positions and molecular marker tests, QLr.hebau-1BL and QLr.hebau-7DS share similar flanking markers with Lr46 and Lr34, respectively. Lr46 and Lr34 are race nonspecific adult plant resistance (APR) genes for leaf rust and stripe rust and powdery mildew. QLr.hebau-4BL showed multiple disease resistance to leaf rust, stripe rust, Fusarium head blight, and powdery mildew. The QTL identified in this study, as well as their closely linked markers, may potentially be used in marker-assisted selection in wheat breeding.

Impact of foliar application of iron and zinc fertilizers on grain iron, zinc, and protein contents in bread wheat (Triticum aestivum L.).

Micronutrient deficiencies, particularly iron (Fe) and zinc (Zn), are prevalent in a large part of the human population across the world, especially in children below 5 years of age and pregnant women in developing countries. Since wheat constitutes a significant proportion of the human diet, improving grain Fe and Zn content in wheat has become important in improving human health. This study aimed to quantify the effect of foliar application of iron sulfate heptahydrate (FeSO4.7H2O) and zinc sulfate heptahydrate (ZnSO4.7H2O) and their combination on grain Fe and Zn concentrations, as well as grain protein content (GPC). The study also aimed to assess the utility of these applications in large field conditions. To address this issue, field experiments were conducted using 10 wheat cultivars and applying a foliar spray of FeSO4.7H2O (0.25%) and ZnSO4.7H2O (0.50%) separately (@400 L of solution in water per hectare during each spray) and in combination at two different crop growth stages (flowering and milking) for three consecutive crop seasons (2017-2020). The study used a split-plot design with two replications to assess the impact of foliar application on GFeC, GZnC, and GPC. In addition, an experiment was also conducted to assess the effect of soil (basal) @ 25 kg/ha ZnSO4, foliar @ 2 kg/ha, ZnSO4.7H2O (0.50%), and the combination of basal + foliar application of ZnSO4 on the grain micronutrient content of wheat cultivar WB 02 under large field conditions. GFeC increased by 5.1, 6.1, and 5.9% with foliar applications of FeSO4, ZnSO4, and their combination, respectively. GZnC increased by 5.2, 39.6, and 43.8% with foliar applications of FeSO4, ZnSO4, and their combination, respectively. DBW 173 recorded the highest increase in GZnC at 56.9% with the combined foliar application of FeSO4 and ZnSO4, followed closely by HPBW 01 at 53.0% with the ZnSO4 foliar application, compared to the control. The GPC increased by 6.8, 4.9, and 3.3% with foliar applications of FeSO4, ZnSO4, and their combination, respectively. Large-plot experiments also exhibited a significant positive effect of ZnSO4 not only on grain Zn (40.3%, p ≤ 0.001) and protein content (p ≤ 0.05) but also on grain yield (p ≤ 0.05) and hectoliter weight (p ≤ 0.01), indicating the suitability of the technology in large field conditions. Cultivars exhibited a slight increase in GFeC with solitary foliar applications of FeSO4, ZnSO4, and their combination. In contrast, a significant increase in GZnC was observed with the foliar application of ZnSO4 and the combined application of FeSO4 and ZnSO4. In terms of GPC, the most significant enhancement occurred with the foliar application of FeSO4, followed by ZnSO4 and their combination. Data demonstrated the significant effect of foliar application of ZnSO4 on enhancing GZnC by 39.6%. Large plot experiments also exhibited an increase of 40.3% in GZnC through the foliar application of ZnSO4, indicating the effectiveness of the technology to be adopted in the farmer's field.

Wheat cultivars grain yield and quality traits variability under conditions of southern Pannonian plain

In order to meet milling industry and grain producers' requirements, wheat grain needs to possess good technological quality, and high and stable grain production. This study analyzed 30 varieties of winter wheat over four growing seasons (2015/16, 2016/17, 2017/18, and 2018/19) at the location Rimski Šančevi, Serbia. The studied traits were under the control of genotype, environment, and their interaction. The analysis of variance (ANOVA) revealed that the influence of the factors varied depending on the studied trait. Thousand grain weight showed the highest variability depending on genotype influence, protein content and sedimentation value that were mostly affected by environmental conditions, while the genotype and environment interaction had the greatest impact on hectoliter weight and grain yield. Using principal component analysis significant positive relationship was observed between protein content and sedimentation value, and between thousand grain weight and hectoliter weight. It was also shown that yield and thousand grain weight, sedimentation value and hectoliter weight are positively related. A strong negative association was noted between grain yield and protein content. The protein content and hectoliter weight did not show any dependency. All analyzed traits are significant for breeding programs, emphasizing the importance of developing high-quality varieties with high yield potential and tolerance to adverse environmental conditions.

Molecular and agro-morphological diversity assessment of some bread wheat genotypes and their crosses for drought tolerance.

Wheat, a staple cereal crop, faces challenges due to climate change and increasing global population. Maintaining genetic diversity is vital for developing drought-tolerant cultivars. This study evaluated the genetic diversity and drought response of five wheat cultivars and their corresponding F1 hybrids under well-watered and drought stress conditions. Molecular profiling using ISSR and SCoT-PCR markers revealed 28 polymorphic loci out of 76 amplified. A statistically significant impact of parental genotypes and their crosses was observed on all investigated agro-morphological traits, including root length, root weight, shoot length, shoot weight, proline content, spikelet number/spike, spike length, grain number/spike, and grain weight/spike. The parental genotypes P1 and P3 had desirable positive and significant general combining ability (GCA) effects for shoot fresh weight, shoot dry weight, root fresh weight, root dry weight, shoot length, and root length under well-watered conditions, while P3 and P5 recorded the highest GCA estimates under drought stress. P3 and P4 showed the highest GCA effects for number of spikelets per spike, the number of grains per spike, and grain weight per spike under normal conditions. P5 presented the maximum GCA effects and proved to be the best combiner under drought stress conditions. The cross P1× P3 showed the highest positive specific combining ability (SCA) effects for shoot fresh weight under normal conditions, while P2×P3 excelled under water deficit conditions. P1× P2, P1 × P3, and P4× P5 were most effective for shoot dry weight under normal conditions, whereas P1×P3 and P3×P5 showed significant SCA effects under drought stress. Positive SCA effects for root fresh weight and shoot length were observed for P3×P5 under stressed conditions. Additionally, P4×P5 consistently recorded the highest SCA for root length in both environments, and P3×P5 excelled in the number of spikelets, grains per spike, and grain weight per spike under drought conditions. The evaluated genotypes were categorized based on their agronomic performance under drought stress into distinct groups ranging from drought-tolerant genotypes (group A) to drought-sensitive ones (group C). The genotypes P5, P2×P5, and P3×P5 were identified as promising genotypes to improve agronomic performance under water deficit conditions. The results demonstrated genetic variations for drought tolerance and highlighted the potential of ISSR and SCoT markers in wheat breeding programs for developing drought-tolerant cultivars.

Different Level of Tolerance to Herbicides is Displayed by Triticum aestivum L. Cultivars Depending on Herbicide Category and Mode of Application

Abstract Herbicides (HBs) are an integral part of modern agricultural practice globally as one of the most suitable methods for chemical weed control. Hence, they may inadvertently damage crops through similar mechanisms well-functioning at weeds. Tolerance to three categories of treatments (tribenuron-methyl, 2,4 D and their combination), and the impact of the mode of application (pre-treatment of seeds or spraying on plants) was assessed through morphometric analysis (total plant length, root length, stem length, lengths of the first three leaves, relative water content-RWC), and pigment content analysis for some wheat (Triticum aestivum L.) cultivars in use in Albania. Results speak of a cultivar specific tolerance to each HB category, discriminating “Dajti” as the most resistant cultivar, and suggesting that the stress imposed to plants by the combination of HBs can produce significant differences in pigment content. The mode of treatment, on the other side showed that glyphosate pre-treatment of seeds led to inhibition of germination, and plants germinated from seed pre-treatment with in 2,4-D displayed significant modification of plant morphology, and germination rate, and had limited impact on RWC. On contrary, few statistically significant changes in morphometric traits and pigments content were evidenced when plants were treated with 2,4-D or glyphosate after the germination. In conclusion, the combination of HBs produced significant changes in plant pigments content compared to the impact of each HB alone, and the pre-treatment of seeds lead either to inhibition or delayed germination. Based on the above we recommend avoiding these practices, and suggest further exploration of alternative HB combinations and modes of treatment before large scale applications.

Selenium accumulation in grains of wheat cultivars grown in selenium-rich areas in China

Selenium accumulation in grains of wheat cultivars grown in selenium-rich areas in China

矮杆冬小麦新品种盈亿166原种种子生产技术规程

矮杆冬小麦新品种盈亿166原种种子生产技术规程