Assay on the impact of seed priming with ionic selenium, nanoselenium and microselenium on early growth, biomolecules and nutrient content in cucumber seedlings

Selenium (Se) is a beneficial nutrient for plants and its application as seed priming is associated with positive effects on their growth. The use of Se occurs in ionic or nanometric form, however, another possible use is in micrometric form, which to our knowledge has not been studied in plants. The objective of the study was to evaluate the seed priming of cucumber (Cucumis sativus L.) with sodium selenite (Na2SeO3), nanoparticles (SeNPs) and Se microparticles (SeMPs) at concentrations of 0, 0.1, 0.5, 1.0, 1.5 and 3.0 mg L-1 of Se, for each of the mentioned forms. Growth, biomass, vigor, biomolecules and nutrients were evaluated in cucumber seedlings grown in a growth chamber for 15 days. The results showed increases in seedling length and biomass for all Se forms, which was reflected in increases in vigor indices from 21.42% to 27.72% for vigor index 1 (length) and from 16.96% to 34.5% for vigor index 2 (biomass), with SeMPs standing out at 1.0 and 1.5 mg L-1. Regarding pigments, variable effects were observed, where some treatments did not modify the concentration of chlorophylls and carotenoids (SeMPs) and others negatively affected (SeNPs and Na2SeO3). Reduced glutathione increased from 13.48% to 31.59%, with SeMPs standing out at 1.0 and 1.5 mg L-1. Phenols, flavonoids, proteins, S, K and Mg were also increased with the different Se materials; however, P, Ca, Fe, Zn, Cu and Mn decreased with some Se treatments. The results indicate that it is advisable to apply Na2SeO3, SeNPs and SeMPs, mainly SeMPs at 1.0 and 1.5 mg L-1

Impact of water regimes on the chemical composition, antioxidant activity and quality of olive oil (Olea europaea L.) under semi-arid conditions in Tunisia

Water scarcity is the main challenge in irregular olive oil production in Tunisia. In olive orchards the use of deficit irrigation technique is the main method to optimize water saving and achieve sustainable olive production. The aim of this study was to assess four levels of drip irrigation (100% ETc, 60% ETc, 50% ETc and 40% ETc (evapotranspiration)) on ‘Chemlali’ and ‘Koroneiki’ olive oil varieties, in semi-arid conditions, for two consecutive crop years. The quality parameters, antioxidant compounds, and antioxidant properties against DPPH and ABTS cation radicals of oils, were evaluated. Moreover, the fatty acid composition of ‘Chemlali’ and ‘Koroneiki’ oils was determined through gas chromatographic analysis. The result showed that irrigation regimes had a moderate effect on the standard quality parameters (free fatty acids, peroxide value, K232 and K270) of virgin olive oil as well as on the composition of the fatty acids. The oil obtained from trees treated with 50% ETc irrigation strategy was characterized by a high content of oleic acid (approximately 61% for ‘Chemlali’ and 78% for ‘Koroneiki’), a low level of palmitic acid, a high content of phenolic compounds (217.44 and 198.99 mg of eq catechin kg-1 of oil for ‘Chemlali’ and ‘Koroneiki’, respectively), O-diphenols, chlorophyll and carotenoids and high antioxidant properties for both olive cultivars. Therefore, this method is considered the best irrigation strategy to optimize water management and improve the quality, the antioxidant content and properties of oil

Unraveling the chloroplast genome of Actiniopteris radiata from Saudi Arabia: Insights into genetic diversity in Pteridaceae

This study reports the chloroplast genome sequence of Actiniopteris radiata from Jazan, Saudi Arabia, marking it as the inaugural fern species of the Actiniopteris genus to be sequenced and analyzed. The chloroplast genome spans 148,219 bp with a GC content of 40.8% and contains 131 genes: 87 protein-coding genes (PCGs), 36 transfer RNAs (tRNAs), and 8 ribosomal RNAs (rRNAs). Comparative analyses with nine related species revealed a genome size range from 148,219 bp (A. radiata) to 154,106 bp (Pteris vittata), with GC content spanning 36.7% (Ceratopteris cornuta) to 44.4% (Adiantum shastense). The analysis identified 538 simple sequence repeats (SSRs) concentrated in the large single-copy (LSC) region. Codon usage analysis showed significant preferences, including an RSCU value of 0.36 for GCT in alanine codons. SNP analysis revealed 25,137 SNPs across the genome, yielding a dS/dN ratios indicative of purifying selection. Notable genes, such as psbD and psaA, exhibited high dS/dN ratios (46 and 8, respectively), suggesting adaptive evolution in photosynthetic pathways. Phylogenetic analysis confirmed the distinct evolutionary position of A. radiata within the Pteridoideae subfamily, highlighting its unique lineage in the absence of close relatives in existing databases. This research establishes a foundational resource for understanding fern evolution in the Pteridaceae family

Morphological characterization and biostimulation of growth, production, and quality of ‘chiltepín’ (Capsicum annuum var. glabriusculum) using an agroecological approach

Of the primary challenge faced in the domestication of chiltepín (Capsicum annuum L. var. glabriusculum [Dunal] Heiser & Pickersgill), the specific requirements of its natural habitat are most important. Therefore, the objective of this research was to conduct a morphological characterization of chiltepín and evaluate the impact of biostimulants on its growth, production, and quality when cultivated outside its native environment. The study was conducted using a completely randomized block design with four treatments (T1-BF, T2-RT, T3-RB, and T4-Ctrl), four replications, and five plants per experimental unit. Morphological analyses revealed significant phenotypic variability between the wild and domesticated varieties, reflecting ecological adaptations and selective pressures that have shaped its evolution. Additionally, the chiltepín showed an outstanding response to biostimulant treatments, particularly T1-BF and T2-RT; these treatments had a significant impact on plant growth and development, improving parameters such as height, stem diameter, chlorophyll content, and canopy density during the first 30 days after transplanting (DAT). Furthermore, these treatments enhanced fruit production and quality, increasing fresh weight (47%), dry weight (46%), length, and length-to-width ratio. These results not only highlight the value of the knowledge gained about the phenotypic features of chiltepín, but also the potential of the agroecological approach using biostimulants to optimize the development, production, and quality of this crop

Influence of genotype, climatic factors and sowing time on maize yield and water release rate

The objective of this paper was to determine the optimal sowing periods for maize in alluvial soil in the semiarid conditions of the southern of Serbia during two successive growing seasons of six maize genotypes from three FAO ripening groups and three sowing periods. Different climatic conditions, temperatures, and amounts of precipitation levels during the examined research period, as well as different sowing periods, had a significant effect on grain yield and yield characteristics variation. The 2014 growing season was more favorable due to a well-distributed rainfall pattern during the critical stages of maize growth, which positively affected thousand-kernel weight and grain yield. Grain yield was significantly higher in 2014 compared to 2015, which was less favorable due to high temperatures and reduced rainfall during the critical growth stages. The genotypes NS 5051 and ZP 555 demonstrated the greatest stability in the number of grains per cob during the second sowing period in the 2014 season. The greatest stability in thousand-kernel weight was achieved by genotype NS 6030 in all three sowing periods in the 2014 season. The genotypes NS 5051 and ZP 555 showed the highest stability of grain yield in all three sowing periods in 2014, and positive interaction with the environment was achieved during the second sowing period in 2015. The results indicate the need for a localized approach when selecting hybrids and adjusting optimal sowing periods to mitigate the negative effects of climate change and to get maximize yield

Induction and expression of systemic resistance to downy mildew disease in grapevine by chitosan

Grapes represent a significant agricultural product globally. Despite their significance and value, grapes face numerous challenges, including disease. Grapevines are susceptible to various pathogens, with downy mildew caused by Plasmopara viticola, being the most damaging. In the twentieth century, contact and systemic fungicides were developed to combat plant pathogens, such as downy mildew. Recently, there has been a growing demand to minimize fungicide use and shift towards sustainability through implementing eco-friendly practices. Utilizing plant defense elicitors to stimulate disease resistance in grapevines is a crucial strategy. We conducted experiments in the field over two seasons, 2021 and 2022, at two different locations using two grape cultivars (‘Flame’ and ‘Crimson’). Four concentrations of chitosan (1, 2, 4, and 8 mM) were applied. The results indicated that chitosan could induce systemic resistance against downy mildew caused by P. viticola by activating the salicylic acid (SA) pathway, increasing the plant’s concentrations of SA and phenols, and augmenting the efficacy and activity of defense enzymes. The treatment also significantly enhanced the yield production of 1.3-glucanase, chitinase, peroxidase, and polyphenol oxidase. The present study assessed the efficacy of chitosan as a resistance inducer in managing grapevine downy mildew and examined its mechanism of action

Evaluating salt tolerance of chickpea genotypes based on morpho-physiological and biochemical parameters

Screening for salinity stress is complicated due to variations in response and sensitivity at different developmental stages of the chickpea crop life cycle. Evaluation of the performance of chickpea in response to NaCl-induced salinity stress at the initial vegetative phase is a quick and cost-effective method for assessing tolerance and survival compared to traditional field approaches. An experiment was carried out under hydroponic conditions to evaluate the performance of two chickpea genotypes (‘Elmo’ and ‘Orion’), under different salinity stress levels (25, 50 and 75 mM NaCl). Increased levels of NaCl in the growing medium caused a significant decrease in leaf relative water content, where the percentage of reduction at the highest salt level was approximately 16.9% compared to the control. ‘Orion’ was able to produce and accumulate a higher amount of proline (3.45 µmol g dwt.-1), compared to the ‘Elmo’ (2.95 µmol g dwt.-1), which enabled plants to absorb a greater quantity of water and maintain a higher relative water content in the ‘Orion’ (88%) compared to ‘Elmo’ (84.1%), and accordingly the percentage of solutes leakage and MDA content were significantly higher in ‘Elmo’ (72.2% and 49.7 µmol g dwt.-1, respectively) compared to ‘Orion’ (60.3% and 29.5 µmol g dwt. -1, respectively). The results indicate the importance of the osmotic adjustment mechanism in maintaining protoplast hydration and membrane stability under salinity stress. Based on the investigated parameters, genotypic differences were found in the response to salt treatments. ‘Orion’ genotype was found to be more salt-tolerant compared to ‘Elmo’ one

Bio-efficacy of plant extracts against a major stored grain insect pest bruchid beetle F. Callosobruchus maculatus (Coleoptera: Bruchidae)

A considerable portion of crops is lost due to the use of non-selective crop protection agents. Consequently, there is growing pressure on the agrochemical industry to develop new crop protection solutions that are both environmentally friendly and safe for consumers. The current study investigates the bio-efficacy of plant extracts (Melia azedarach L., Nicotiana rustica L., Azadirachta indica L., Nicotiana tabacum L., and Thuja orientalis L.,) against Callosbruchus maculatus. The extracts of these plants were tested at six different concentrations (5, 10, 15, 20, 25, and 30%) using distilled water as a control. The experiments were replicated four times. Overall mean minimum oviposition (131.75), adult emergence (73.78%), infestations (28.14%) and host seed weight loss (12.54%) were observed with N. tabacum. Contact and residual methods were used to evaluate the toxic effects of the plant extract after 24-, 48-, 72- and 96-hours’ exposure period. The LC50 and LC90 values were determined by probit analysis. In case of residual toxicity, out of the five plant species extract, N. tabacum was the most toxic against C. maculatus with LC50 of 0.92% and LC90 of 4.77 % respectively. In contact toxicity N. tabacum was found effective against C. maculatus with LC50 of 0.14% and LC90 of 1.59% respectively. Alkaloids, saponins, di-terphenes, phyto-sterol, flavonoids and phenols were detected in the aqueous extracts of selected plant species. The current study highlights the efficacy of N. tabacum, N. rustica and A. indica for the management of C. maculatus. Further investigation is therefore necessary to evaluate the potential of these plant species for the production of new bio-pesticides as safer and eco-friendlier alternative to synthetic pesticides

Site-specific factors influencing Hymenoscyphus fraxineus spore dispersal: the role of understorey vegetation and slope steepness in ash dieback spread

Ash dieback (ADB), caused by Hymenoscyphus fraxineus, is a severe threat to Fraxinus excelsior populations across Europe, with spore dispersal playing a critical role in disease progression. While broad-scale environmental drivers of spore dispersal are well studied, site-specific factors remain underexplored. This review uniquely explores how understorey and slope steepness influence the dispersal, deposition, and development of H. fraxineus spores, along with stand management strategies reported to impact ADB disease progression. The dense understorey vegetation creates microclimatic conditions favouring spore development and retention through increased humidity, reduced airflow, and light accessibility, while also potentially modifying transmission dynamics. Slope steepness may affect spore dynamics through gravity-driven movements of infected ash rachises, and microclimatic variation associated with slope aspect. Understanding these site-specific effects can enhance disease management strategies aimed at conserving tolerant individuals and preserving the genetic basis of tolerance for future Fraxineus excelsior generations. The review also identifies knowledge gaps and highlights the need for empirical research on context-specific management strategies across diverse forest landscapes

Effects of different ratios of nitrogen–calcium fertilization on growth and photosynthetic characteristics in the endangered plant Excentrodendron hsienmu seedlings

Excentrodendron hsienmu, a karst-endemic tree species of high ecological and economic value, is classified as endangered and nationally protected in China. This study aimed to establish a theoretical basis for the propagation and conservation of E. hsienmu by evaluating the effects of nitrogen–calcium fertilization on seedling growth and photosynthetic performance. One-year-old seedlings were subjected to nine treatment combinations of pure nitrogen (1.0, 2.0, 3.0 g/plant) and pure calcium (1.5, 3.0, 4.5 g/plant). Results showed that all fertilization treatments significantly improved seedling growth and photosynthetic traits compared to the control. The N2Ca2 treatment (2.0 g N and 3.0 g Ca per plant) yielded the highest increases in height (26.20 cm), ground diameter (6.96 mm), total biomass (85.64 g), root system development, and chlorophyll content. Additionally, photosynthetic parameters such as net photosynthetic rate (13.96 µmol·m-²·s-¹) and transpiration rate (4.21 mmol·m-²·s-¹) were significantly enhanced under N2Ca2. All measured characteristics, except stomatal conductance, differed significantly from the control (p < 0.05). These findings provide a scientific foundation for the optimized cultivation, restoration, and conservation of E. hsienmu