The present study aimed to evaluate the ameliorative effects of foliar-applied nanoparticles on growth, nutrient uptake, essential oil content, and physiological responses of Pelargonium graveolens under salt stress. A factorial experiment was conducted based on a completely randomized design with 3 replications. Plants were subjected to three salinity levels (0, 75, and 150 mM sodium chloride) and foliar spray of TiO2 (2 mg L⁻¹), Mn oxide-graphene oxide (10 mg L⁻¹), molybdenum trioxide nanoparticles (0.5 µM), or no spray (control). Salt stress significantly reduced biomass, nutrient content (N, P, Ca), and adversely enhanced malondialdehyde content. The highest biomass and nutrients content were observed under no-saline conditions + all nanoparticle treatments, and under 75 mM NaCl + Mn oxide-GO and MoO₃ sprays. Essential oil content was the highest at 0 mM and 150 mM NaCl + MoO₃, and at 75 mM NaCl + all three foliar treatments. MDA levels peaked at 44 (75 mM NaCl) and 49 nmol g⁻¹ FW (150 mM NaCl) without foliar sprays. In conclusion, P. graveolens tolerated salinity of up to 75 mM NaCl when supplemented with foliar Mn oxide-GO and MoO₃ nanoparticles. These treatments mitigated salinity-induced oxidative damages, improved nutrient status and enhanced essential oil yield, highlighting their potential as stress-alleviating agents under saline conditions.
Cryopreservation offers a valuable approach for the long-term conservation of plant genetic resources, but its influence on seed viability and plant development remains underexplored. This study investigates the physiological and biochemical effects of different pre-cryopreservation drying treatments on Catharanthus roseus seeds. Seeds were subjected to silica gel desiccation and oven drying before immersion in liquid nitrogen (-196°C). Results showed that a moderate oven drying period (10 minutes) preserved high seed viability and led to optimal plantlet growth, mirroring untreated controls. In contrast, prolonged silica gel drying (3, and 9 hours) as well as drying for 20 min in oven significantly reduced germination rates, plantlet height, biomass, and levels of carbohydrates and alkaloids. Anatomical evaluations revealed improved vascular and mesophyll structures in plantlet leaves derived from oven-dried seeds, while moderate silica gel exposure increased epidermal thickness, indicating enhanced stress resilience. Hormonal analyses showed higher gibberellic acid (GA₃) and lower abscisic acid (ABA) levels in successfully germinated seeds. In conclusion, the study emphasizes the importance of pre-cryopreservation drying for optimizing plantlet performance and plant development with implications for pharmaceuticals. Thus, this research contributes to refining cryopreservation strategies for sustainable conservation of medicinal plants like Catharanthus roseus plants.
Litchi (Litchi chinensis Sonn.) is a high-value tropical fruit, yet it suffers from rapid postharvest deterioration. This research appraised the combined effects of chitosan (CHT) coatings and hot water (HW) treatments on the shelf life, physicochemical quality, and antioxidant retention of litchi cv. China-3. Fruits were treated with 0.5% or 1% CHT, alone or following HW immersion (50°C for 5 minutes), and stored at ambient temperature. The combination of CHT with HW significantly reduced weight loss, decay, and browning index, while extending shelf life 35.71% longer than untreated fruits. This treatment preserved firmness, attenuated the decline in titratable acidity (TA), and minimized increases in total soluble solids (TSS). After 9 Days of Storage (DAS) at ambient temperature, fruits treated with 0.5% CHT + HW maintained higher levels of β-carotene (6.84 µg/100 g), total sugar (TS) (21.27%), ascorbic acid (46.99 mg/100 g), phenolics (12.60 mg/g), and flavonoids (3.13 mg/g) compared to untreated fruits, indicating a beneficial effect on the nutritional quality of the fruits. The antioxidant activity (DPPH* scavenging activity) was also significantly higher (45.04%) in treated fruits compared to the control (29.75%). Furthermore, compared to the control, the treatment delayed colour degradation, preserved lightness (L*=22.14), and achieved superior sensory ratings in flavour, sweetness, appearance, and overall acceptability. These findings suggest that combining 0.5% CHT with HW is an eco-friendly postharvest strategy to enhance storage stability, retain nutritional and sensory qualities in litchi.
Digitalis purpurea L. is a valuable medicinal and ornamental species, but its conventional propagation is constrained by low seed germination and high genetic variability. The present study aimed to develop an efficient and reproducible in vitro regeneration system for D. purpurea through both direct and indirect organogenesis by optimizing explant type and plant growth regulator (PGR) combinations. Among the explants evaluated, hypocotyl-cotyledon (flamingo) explants exhibited the highest morphogenic competence, whereas leaf and root explants showed no regenerative response under any treatment. In direct organogenesis, MS medium supplemented with 0.25 mg L⁻¹ thidiazuron (TDZ) was the most effective, producing the maximum shoot length (6.3 mm) and shoot number (8.6 shoots per explant). Indirect organogenesis was strongly influenced by auxin type, with callus induction reaching 100% in flamingo explants cultured on media containing 0.5-1 mg L⁻¹ NAA, while 2,4-D was markedly less effective. Shoot regeneration from callus was significantly enhanced by cytokinin-polyamine interactions, with the highest shoot proliferation (up to 28 shoots per callus) and superior shoot elongation obtained on MS medium supplemented with 0.25-0.5 mg L⁻¹ BAP in combination with 50 mg L⁻¹ putrescine. Root induction was optimized on half-strength MS medium containing IBA, where 0.25 mg L⁻¹ IBA resulted in the highest rooting frequency (91%), maximum root number, and well-developed roots. Overall, this study highlights the critical role of explant selection and tailored PGR-polyamine combinations in establishing a high-efficiency micropropagation protocol for D. purpurea, providing a reliable platform for large-scale propagation and future biotechnological applications.
Ferulic acid (FA) and salicylic acid (SA) are phenolic compounds with recognized potential as metabolic elicitors in plants. This study evaluated the effects of exogenous application of FA and SA (0.5 mmol L⁻¹), applied individually or in combination, on the morphophysiological and biochemical responses of tomato cv. Santa Clara. The experiment was conducted in a greenhouse using plants cultivated in pots. Morphophysiological evaluations included growth and yield parameters, while biochemical analyses comprised photosynthetic pigments, soluble sugars, and phenolic compounds in the fruits. FA increased chlorophyll content and soluble sugars, whereas SA enhanced the accumulation of polyphenols and flavonoids. The combined application of FA+SA led to greater increases in leaf area, plant height, fruit number, fruit diameter, and biomass production, particularly root dry mass. In addition, the combined treatment improved the accumulation of bioactive compounds associated with fruit nutritional quality. Overall, the results indicate that FA and SA, particularly when applied together, represent a promising strategy to enhance tomato growth, productivity, and fruit quality under protected cultivation conditions.
