Exogenously applied silver nanoparticles (AgNPs) differentially affect bacterial blight disease control in twenty-seven wheat cultivars.

The bacterial blight of wheat is an important global disease causing a significant decline in crop yield. Nanotechnology offers a potential solution for managing plant diseases. Therefore, this research aimed to investigate the effectiveness of silver nanoparticles (AgNPs) in controlling bacterial blight in 27 locally grown wheat cultivars. The study examined the impact of AgNPs at three distinct time points: 1, 3, and 5 days after the onset of the disease. Biochemical assay revealed that one day after applying the disease stress, the Inia cultivar had the highest amount of soluble protein (55.60 µg.g-1FW) content in the treatment without AgNPs. The Azadi cultivar, without AgNPs treatment, had the lowest amount of soluble protein content (15.71 µg.g-1FW). The Tabasi cultivar had the highest activity of the superoxide dismutase (SOD) (61.62 mM.g-1FW) with the combination treatment of AgNPs. On the other hand, the Karchia cultivar had the lowest SOD activity (0.6 mM.g-1FW) in the treatment of disease without AgNPs. Furthermore, three days after the application of stress, the Mahdavi cultivar had the highest amount of soluble protein content (54.16 µg.g-1FW) in the treatment of disease without AgNPs. The Niknejad cultivar had the highest activity of the SOD (74.15 mM.g-1FW) with the combined treatment of the disease without AgNPs. The Kavir cultivar had the lowest SOD activity (1.95 mM.g-1FW) and the lowest peroxidase (POX) activity (0.241 mM g-1FW min-1) in the treatment of the disease with AgNPs. Five days after exposure to stress, the Mahooti cultivar had the highest SOD activity (88.12 mM.g-1FW) with the combined treatment of the disease with AgNPs, and the Karchia cultivar had the lowest SOD activity (2.39 mM.g-1FW) in the treatment of the disease with AgNPs. Further, the results indicated that exposure to AgNPs could improve the antioxidant properties of wheat seeds in blight-infected and disease-free conditions in some cultivars.

Application of artificial neural networks to classify Avena fatua and Avena sterilis based on seed traits: insights from European Avena populations primarily from the Balkan Region.

BACKGROUND: Avena fatua and A. sterilis are challenging to distinguish due to their strong similarities. However, Artificial Neural Networks (ANN) can effectively extract patterns and identify these species. We measured seed traits of Avena species from 122 locations across the Balkans and from some populations from southern, western, and central Europe (total over 22 000 seeds). The inputs for the ANN model included seed mass, size, color, hairiness, and placement of the awn attachment on the lemma. RESULTS: The ANN model achieved high classification accuracy for A. fatua and A. sterilis (R2 > 0.99, RASE < 0.0003) with no misclassification. Incorporating geographic coordinates as inputs also resulted in successful classification (R2 > 0.99, RASE < 0.000001) with no misclassification. This highlights the significant influence of geographic coordinates on the occurrence of Avena species. The models revealed hidden relationships between morphological traits that are not easily detectable through traditional statistical methods. For example, seed color can be partially predicted by other seed traits combined with geographic coordinates. When comparing the two species, A. fatua predominantly had the lemma attachment point in the upper half, while A. sterilis had it in the lower half. A. sterilis exhibited slightly longer seeds and hairs than A. fatua, while seed hairiness and mass were similar in both species. A. fatua populations primarily had brown, light brown, and black colors, while A. sterilis populations had black, brown, and yellow colors. CONCLUSIONS: Distinguishing A. fatua from A. sterilis based solely on individual characteristics is challenging due to their shared traits and considerable variability of traits within each species. However, it is possible to classify these species by combining multiple seed traits. This approach also has significant potential for exploring relationships among different traits that are typically difficult to assess using conventional methods.

Seed bio-priming with beneficial Trichoderma harzianum alleviates cold stress in maize.

Maize is one of the major crops in the world and the most productive member of the Gramineae family. Since cold stress affects the germination, growth, and productivity of corn seeds, the present study aimed to investigate the effect of seed biopriming with Trichoderma harzianum on the tolerance of two genotypes of maize seedlings to cold stress. This study was conducted in triplicates in factorial experiment with a complete randomized block design (CRBD). The study was conducted in the greenhouse and laboratory of the University of Mohaghegh Ardabili, Ardabil, Iran. Experimental factors include two cultivars (AR68 cold-resistant and KSC703 cold-sensitive maize cultivars), four pretreatment levels (control, biopriming with T. harzianum, exogenous T. harzianum, and hydropriming), and two levels of cold stress (control and cold at 5 °C) in a hydroponic culture medium. The present study showed that maize leaves' establishment rate and maximum fluorescence (Fm) are affected by triple effects (C*, P*, S). The highest establishment (99.66%) and Fm (994 units) rates were observed in the KP3 control treatment. Moreover, among the pretreatments, the highest (0.476 days) and the lowest (0.182 days) establishment rates were related to P0 and P3 treatments, respectively. Cultivar A showed higher chlorophyll a and b, carotenoid content, and establishment rate compared to cultivar K in both optimal and cold conditions. The highest root dry weight (11.84 units) was obtained in cultivar A with P3 pretreatment. The pretreatments with T. harzianum increased physiological parameters and seedling emergence of maize under cold and optimal stress conditions. Pretreatment and cultivar improved catalase activity in roots and leaves. Higher leaf and root catalase activity was observed in the roots and leaves of cultivar K compared to cultivar A. The cold treatment significantly differed in peroxidase activity from the control treatment. Cultivar K showed higher catalase activity than cultivar A. The main effects of pretreatment and cold on polyphenol oxidase activity and proline content showed the highest polyphenol oxidase activity and proline content in hydropriming (H) treatment. Cold treatment also showed higher polyphenol oxidase activity and proline content than cold-free conditions.

Microbial seed coating: An attractive tool for sustainable agriculture.

Seed coating is considered one of the best methods to promote sustainable agriculture where the physical and physiological properties of seeds can be improved to facilitate planting, increase growth indices and alleviate abiotic and biotic stresses. Several methods of seed coating are used to attain good application uniformity and adherence in the seed coating process. Seed coating has been tested in seeds of various plant species with different dimensions, forms, textures, and germination types. Plant beneficial microorganisms (PBM), such as rhizobia, bacteria, and fungi inoculated via seed inoculation can increase seed germination, plant performance and tolerance across biotic (e.g., pathogens and pests) and abiotic stress (e.g., salt, drought, and heavy metals) while reducing the use of agrochemical inputs. In this review, the microbial seed coating process and their ability to increase seed performance and protect plants from biotic and abiotic stresses are well discussed and highlighted in sustainable agricultural systems.

Efficacy of biological agents and fillers seed coating in improving drought stress in anise.

Many plants, including anise, have tiny, non-uniform seeds with low and light nutrient reserves. The seeds also show a weak establishment, especially under stressful conditions where their accurate planting in the soil and optimal yield are tough. This study sought to improve anise seeds' physical and physiological characteristics under drought stress. To this end, two factorial experiments under laboratory and greenhouse conditions were performed in a completely randomized design with 4 and 3 replications, respectively. Five levels of seed inoculation (inoculation with T36 and T43 of Trichoderma harzianum, and CHA0 and B52 of Pseudomonas fluorescent, and non-inoculation which means that control seeds were not treated with microbial inoculant), three levels of coating (K10P20, K10P10V5, and non-coating), and three levels of drought stress (0, -3, and -6 bars) were considered as the factorial experiment [vermiculite (V), kaolin (K), and perlite (P) numbers refer to the amount of material used in grams]. The laboratory experiment revealed that the combined treatments of bio-agents with coating increased the physical and germination characteristics of anise seeds compared to the control treatment. The greenhouse experiment showed that drought stress reduced the initial growth indices. Still, the combination treatments of biological agents and coating (fillers) could alleviate the destructive effects of drought stress to some extent and improve these indices. The best treatment was provided by T36 and K10P20 in both experiments, which significantly increased morphological indices.