Severe water stress conditions limit growth and development of floricultural crops which affects flower quality. Hence, development of effective approaches for drought tolerance is crucial to limit recurring water deficit challenges. Foliar application of various plant growth regulators has been evaluated to improve drought tolerance in different floricultural crops; however, reports regarding the role of chitosan (Ci) on seasonal flowers like calendula are still scant. Therefore, we evaluated the role of Ci foliar application on morphological, physiological, biochemical, and anatomical parameters of calendula under water stress conditions. Different doses of Ci (0, 2.5, 5, 7.5, 10 mg L−1) were applied through foliar application to evaluate their impact in enhancing growth and photosynthetic pigments of calendula. The optimized Ci level of 7.5 mg L−1 was further evaluated to study mechanisms of water stress tolerance in calendula. Ci application significantly increased biomass and pigments in calendula. Ci (7.5 mg L−1) resulted in increased photosynthetic rate (72.98%), transpiration rate (62.11%), stomatal conductance (59.54%), sub-stomatal conductance (20.62%), and water use efficiency (84.93%). Furthermore, it improved catalase, guaiacol peroxidase, and superoxide dismutase by 56.70%, 64.94%, and 32.41%, respectively. These results highlighted the significance of Ci in inducing drought tolerance in pot marigold.
Salt stress is hampering plant growth and development especially in arid and semiarid regions due to enhanced evapotranspiration and underground brackish irrigation water. A pot experiment was therefore conducted to assess the malicious effects of salinity on two potato (Solanum tuberosum L.) cultivars namely N-Y LARA and 720-110 NARC. Various salinity levels (control, 2.5, 5.0, 7.5, 10.0 and 12.5 dS m -1 , developed with NaCl) were induced after 30 days of tuber emergence. Both the cultivars proved to be significantly (p≤0.05) affected by salt stress. However, N-Y LARA was less affected than 720-110 NARC. Salinity stress drastically reduced potassium (K + ) contents, protein contents, water relations and gas exchange attributes. However, sodium (Na + ) contents, Na + : K + ratio, leaf electrolyte leakage, proline contents, melondialdehyde (MDA) contents and antioxidant enzymes activities like superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were increased with increasing salinity stress. Conclusively, salt tolerance potential is cultivar dependent as both cultivars exhibited diverse performance vis-à-vis various studied attributes against different NaCl levels.
Strawberry is a delicate fruit with a short shelf life after harvest. High metabolic activities and fungal decay deteriorate its quality. In an attempt to extend its shelf life and maintain its quality while retaining its antioxidant potential, the harvested fruits of strawberry cv. Chandler were dipped in 30% eucalyptus leaf extract (ELE). Weight loss, fungal decay index, percentage of decayed fruits, respiration rate, and electrolyte leakage were all reduced in ELE-treated strawberries. The enzymatic activities of catalase in fruits increased initially until the fifth day of storage but then started to decline during the later period while superoxide dismutase and peroxidase activities continued to rise until the 10th day and then declined. With higher contents of total phenolics, ascorbic acid, total antioxidants, and anthocyanin, the application of ELE maintained the general acceptance, firmness, flavor, and marketable fruit percentage. Titrable acidity (TA) and sugar–acid ratio (SAR) were also significantly affected by ELE application. A declining trend was observed in TA during storage, along with an increase in SAR. The pH and soluble solid contents of strawberry juice were not significantly changed by the application of ELE; however, both attribute scores were greater than those for the control. In conclusion, ELE could be used as an environmentally safe method to postpone senescence and maintain postharvest quality for up to 15 days.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.