---

In this study, the impact of marigold and spirulina, both in isolation and in conjunction with one another, was analyzed on several indicators relating to growth, immunity, survival, and levels of astaxanthin present in zebrafish tissue. 120 zebrafish were randomly allocated to 10 litre aquariums across four different treatment groups (with three replications in each group, each containing 30 fish). The control diet is based on the basic diet, the second treatment diet contains 25 g/kg of spirulina powder (SP) on the basic diet, the third treatment diet contains 25 g/kg of marigold powder (MG) on the basic diet, and the fourth treatment diet It also contains 25 grams of marigold powder (MG) and 25 grams of spirulina (SP+MG)/kg of the basic feed. At the end of the experiment, some immune indicators and astaxanthin were checked in the tissue. The results of this study show the significant effect of spirulina (SP), marigold powder (MG), and the combination of spirulina and marigold powder (SP+MG) on immunity, and astaxanthin. Especially the marigold and the combined treatment of spirulina and marigold showed better performance (P<0.05). respectively, SP+MG and MG treatment significantly increased total protein, lysozyme, and astaxanthin in fish tissue, and the highest amount of IgM was observed in MG treatment (P<0.05). However, no significant difference was observed in relation to growth and survival.

 

---

In the present study, the extract containing bioactive compounds from marigold (Calendula officinalis L.) medicinal plant was extracted using water, ethanol, acetone, ethanol/water and acetone/water as solvent. Among the solvents studied, the ethanolic extract contained the highest total phenolic compounds. The effect of the solvent to raw material ratio (40:1-10:1 mL/g) and particle size (0.5-2.36 mm) on the quantitative and qualitative properties of ethanolic extract at ambient temperature (25°C) were investigated. Based on the results, the highest crude extraction yield and total phenolic compounds equal to 3.5 ± 0.17% and 36.94 ± 0.81 mg GAE/gram of sample was obtained using a ratio of 30:1 mL/g and a particle size of 1 mm at ambient temperature. At the concentration of 1 mg/ml, the antioxidant activity of the extract was 62.95 ± 2.68 % and 153.18 ± 1.20 μΜ Fe²⁺/L, respectively. The high correlation coefficient (R²>09594) between total phenolic compounds and antioxidant activity indicates the key role of phenolic compounds in antioxidant activity. Finally, the ethanolic extract obtained from C. officinalis under mentioned conditions can be introduced as a natural source of phenolic antioxidants for application in the food and nutraceutical industry as a natural preservative.

 

---

 The first experiment was performed to study the effect of foliar application of spermidine, citric acid and proline (0, 50 and 100 mg L^-1) on some metabolites and enzymatic activities of Calendula officinalis L. under drought stress (No stress: Control, 25, 50, and 75% field capacity). The second experiment was performed to study the effect of foliar application of spermidine, citric acid and proline (0, 50 and 100 mg L^-1) on the post-harvest shelf life of flowers (beginning of the experiment, 5, and 10 days post-harvest). The experiments were factorial in a completely randomized design with 3 replications. All treatments had a significant effect on the measured variables. In the first experiment, FC 25% reduced all traits, FC 75% increased carotenoid, carbohydrate, phenol, flavonoid, protein, Peroxidase (POD) and Superoxide Dismutase (SOD) activities. The highest vitamin C was observed in the control FC. Also, foliar application of 100 mg L^-1 proline, increased carotenoid, carbohydrate and phenol, 50 mg L^-1 proline increased protein content. Also, 100 mg L^-1 of spermidine increased flavonoid and 100 mg L^-1 of citric acid increased vitamin C, SOD and POD activities. In the second experiment, all evaluated traits were reduced ten days after harvest, the highest post-harvest life was for 100 mg L^-1 of citric acid (9.7 days) and the lowest was for the control (5.3 days). The study results showed that application of 100 mg L^-1 spermidine, citric acid and proline with FC 75% improved biochemical properties, nutritional traits, and post-harvest life of Pot marigold.