Document Type : Research Paper

Authors

• F. Mohammadi Dolatabad ¹
• M. Sanikhani ¹
• M. Yaghoobi ²
• A. Kheyri ³

¹ Department of Horticultural Sciences, Faculty of Agriculture, University of Zanjan, Iran

² Department of Chemical Engineering, Faculty of Engineering, University of Zanjan, Zanjan, Iran

³ Department of Horticultural Sciences, Faculty of Agriculture, University of Zanjan,Iran

Abstract

Background and objectives: Punica granatum L. var. pleniflora is an ornamental/medicinal shrub native to Iran. Gulnar extract, like morphine, reduces pain in patients. It is also used against various diseases such as prostate cancer and breast cancer due to triterpenoids. In traditional medicine, it has been applied to cure diarrhea, bleeding, mucous secretions, and vaginal secretions. In external use, it has been used as a gargle to cure tonsillitis. Atherosclerosis is one of the most dangerous factors in cardiovascular disease. Due to antioxidant compounds, Gulnar reduces artery-clogging by almost 70%. Therefore, it is critical to enhance Persian Gulnar growth and flowering, a natural source of antioxidants.
Methodology: To investigate the effect of the amino acids tryptophan, phenylalanine, and methionine on the morphophysiological and phytochemical characteristics of the Persian Gulanar, an experiment was conducted in the research greenhouse of Zanjan University in a completely randomized design including ten treatments in three replications and 3 pots for each experimental unit in the research greenhouse, Faculty of Agriculture of Zanjan University. Different levels of treatment included methionine 0.5, 1, 2 mM, phenylalanine 0.5, 1, 2 mM, tryptophan 0.5, 1, 2 mM. The extraction conditions were optimized for total phenol, total flavonoid, antioxidant activity, and antimicrobial activity tests. To extract and optimize the extraction using a dry flower sample, an ultrasonic device was used and an experiment was designed to determine the appropriate solvent, temperature, and duration of extraction, as well as to determine the optimal ratio of plant dry matter to solvent, and a comparison was made between two water solvents and alcohol at temperatures of 30-50-70 degrees Celsius and different amounts of plants 0.2, 0.35, and 0.5 grams per ten milliliters of solvent and durations of 5, 15, 25 minutes. Based on these cases, the initial tests by recommended software. To investigate the antimicrobial activity of the flower extract and Persian Gulnar's red color, a good penetration method was used. Plates containing a solid culture medium of Mueller Hinton agar were used in this method.
Results: The treatments significantly affected the dry weight of flowers and flavonoids at a 5% probability level. In addition, they affected the number of flowers, anthocyanin content, antioxidant activity (FRAP), and chlorophyll b at a 1% probability level. The flower dry weight increased by 97.09% in the presence of 2 mM tryptophan compared to the control. The most anthocyanin was observed with an increase of 56.05 and 50% in the concentration of 0.5 mM phenylalanine compared to the control. The highest amount of antioxidant activity (FRAP) was obtained with a 110% increase compared to the control at a concentration of 2 mM tryptophan. The highest flower number was at 1 mM phenylalanine and 2 mM methionine. The most positive correlation (*r=0.68) was between flower dry weight and branch growth, and the most negative correlation (*r=0.80) was between chlorophyll b and anthocyanin. There was a significant positive correlation between chlorophyll a and total flavonoids, chlorophyll b, and branch growth. Also, there was a significant positive relationship between the number of flowers with anthocyanin and total phenol. The best extraction point was related to the temperature of 70 ºC, 70% ethanol solvent, 15 minutes, and the ratio of plant dry matter to solvent was 0.2 grams of dry weight in 10 ml of solvent. The red flowers showed a higher inhibitory effect against Escherichia coli, and the variegated flowers had a higher inhibitory power against Staphylococcus aureus.
Conclusion: According to the results, in addition to confirming Gulnar's antibacterial activity and determining the optimal extraction point, it was found that the levels of 0.5 mM amino acids in most of the traits, including branch growth, flower dry weight, total phenol, and anthocyanin brought the best results from the treatment. It also justifies them in the field. Since amino acid fertilizers are applied in small amounts, they are economically justified.

Keywords

• Anthocyanin
• pomegranate
• flower
• phenolic content
• foliar application