Although goldenrod (Solidago canadensis) is considered an invasive plant in many countries, it is a global cut-flower species. In addition, demand for goldenrod has increased significantly in recent years. Thus, the present study aimed to evaluate the response of Solidago canadensis cv. Tara to brassinosteroids (BRs) at levels of 0.10⁻³, 10⁻⁶, and 10⁻⁸ M, and chitosan at 0, 100, 150, and 200 mg/L as a foliar application to increase the quality and quantity of production, and its polyphenolic compounds. Moreover, antibacterial activity and genetic polymorphism for both untreated and the optimally treated goldenrod were investigated. The results showed that the highest mean of growth characteristics was found when plants were treated with BRs at 10⁻⁸ M, whereas the longer vase life was obtained using 200 mg/L chitosan. Furthermore, higher pigment values, N, P, K, and total phenolic content, antioxidant capacity, chlorogenic acid, and rutin content were detected on plants treated with 200 mg/L chitosan. In addition, foliar application with 200 mg/L chitosan caused higher antibacterial activity among the control and BRs. The optimal treatment of BR at 10⁻⁸ M (89%) showed a low genetic similarity, based on sequence-related amplified polymorphism (SRAP) analysis, comparable with the control and 200 mg/L chitosan. BR at 10⁻⁸ M and 200 mg/L chitosan showed a significant enhancement of growth parameters. As a result, it can be concluded that goldenrod, as a herb extract, shows significant promise as a natural preservative in pharmaceutical, food, and cosmetic products.

Calendula officinalis is well-Known for medical, ornamental, and cosmetic uses. This plant has a variety of secondary metabolites (carotenoids, flavonoids, steroids, and terpenoids) that may be a source of antioxidants. These chemical components have various biological effects, such as antioxidant, anti-cancer, and anti-inflammatory activates. However, salinity stress limited the growth and productivity of Calendula officinalis as a result of physiological, biochemical, and morphological changes. Hydrogel use is an alternative for reducing the harmful impact of salt stress. So, this study aimed to estimate the effects of hydrogel applied in Calendula officinalis grown under salt stress. The experiment design includes three replications, a factorial randomized complete block design with two factors, using three concentrations of salinity (0, 200 and 3000 ppm) and three different levels of hydrogel polymer (0, 0.4, and 0.6% w/w) both added to the soil before planting and the interaction between them. The results observed that the most significant increase in growth and flowering parameters was treatment with hydrogel alone at 0.6% (w/w). Similarity, salt tolerance index (STI), photosynthetic pigments in fresh leaves, lycopene and β-carotene pigments in fresh petals, elements (N, P, and K) in shoot and root and protein analysis. Whereas the highest content of total sugar, phenol, proline, antioxidant enzymes activity Catalase (CAT),Superoxide dismutase (SOD), and Peroxidase (POD), content of elements (Na and Cl), and decreased of some protein bands in the leaves and total free amino acid content was obtained from plants treated with salinity at 3000 ppm alone without hydrogel. In addition, the interaction between hydrogel at 0.6% (w/w) and 3000 ppm salinity showed a positive impact on most growth parameters and chemical analysis as well as overcoming the negative effect of salinity stress of Calendula officinalis L. plant.

Background: Nanotechnology has provided innovative use of various materials with unique properties. These substances may react positively in plants, and the induction of bioactive compounds and antioxidant activity is particularly remarkable. Ornamental plant production is a positive economic activity of great interest, especially Carnation (Dianthus caryophyllus L.). This plant is more attractive for its various colors, but the flower quality and its longevity can diminish very fast. Thus, examining methods capable of improving flower quality and vase life is crucial. Additionally, carnation can be used to treat coronary and nervous disorders. Carnation contains compounds that calm the nervous system and minimize swelling and inflammation. Objective: This research aimed to evaluate the effect of silica nanoparticles (SiO₂ NPs) on the growth, bioactive chemical analysis, enzyme activity, and antioxidant accumulation. Material and methods: The different rates of SiO₂ NPs (0, 150, and 300 ppm) were used in two ways: foliar spray and soil drench; it was applied 3 times. The first application was after 3 weeks of transplanting and repeated with 21-day intervals. Results and conclusion: The results showed that foliar application of SiO₂ NPs increased all morphological and flowering traits compared with drench and the control, higher levels of photosynthetic pigments and anthocyanin, greater total phenols, total sugars, and total free amino acids were obtained from plants treated with foliar spray 300 ppm followed than 150 ppm. In addition, the greatest levels of enzyme activity were recorded with plants treated with foliar spray of SiO₂ NPs at a rate of 300 ppm, as well as improved anatomical structure of the stem and stomata properties compared with the drench method and control. Similarly, SiO₂ NPs application method is more critical than their concentration. Therefore, it is recommended that foliar spraying of SiO₂ NPs at 300 ppm can enhance plant growth, flowering, bioactive compounds, enzyme activity, and anatomical structure of the stem of carnation plants while adding SiO₂ NPs drench at a rate of 150 ppm had rather acceptable findings.

Solidago canadensis L. cv. ʽTaraʼ as important flower production and traditional medicine. Heavy metals such as lead (Pb) have harmful effects on ornamental plants. So, this study aimed to reduce the toxic effect of Pb on Solidago canadensis plant through spermine(SPM) application. Plants were grown in treated soils with different Pb levels (0, 400, and 800 ppm) and sprayed with spermine at 0, 1 and 2 mM. Plant height, leaf number, total leaf area, stem diameter, number of inflorescences, length of inflorescences stem, fresh & dry weights of shoot, root & inflorescences and flowering period were recorded as growth characters. Photosynthetic pigments, antioxidant enzymes, total sugars, total soluble phenols, total free amino acids, proline, minerals (N, P, K, Pb) and protein as chemical contents. Results showed that Pb at 800 ppm resulted in the lowest values for most tested characteristics, but increased Pb level in shoots and roots. Spermine treatments especially 2mM were highly significant in most characteristics under Pb conditions, except Pb concentration reduction as compared to the control. Results provided evidence that spermine minimized the adverse effects of lead (Pb) stress and could play an essential role in providing stress tolerance.

This study aim to use environmentally friendly material (Linseed and citrus oils) to reduce the harmful effect of water deficit on Khaya senegalensis plant due to its economic importance as a source of wood in addition to many uses of alternative medicine. Therefore, Khaya senegalensis plants were grown in green house with three irrigation intervals (5, 7 and 9 days) and oils foliar spray as linseed oil (Lin) at (0, 5, 7%) and citrus oils at (0, 1, 2%). The results indicated that the 9 days irrigation interval gave the lowest values of the most studied growth parameters, water relations (relative water content (RWC%), water retention capacity (WRC) and membrane stability index(MSI%), photosynthesis pigments, chlorophyll stability index (CSI%), minerals content, total free amino acid while increased values of electrolyte leakage (EL%), total sugar, total phenol, and antioxidant enzymes activities(Catalase (CAT), Peroxidase (POX), Superoxide dismutase (SOD)). Both oils treated especially linseed oil, at 7% increased values of all parameters and chemical composition compared with untreated plants plus different irrigation intervals, except EL% was decreased. The data provided evidence that linseed and citrus oils treatment reduces the adverse effect of water deficit on Khaya senegalensis plants and can play a role in providing stress tolerance.