Volume 18, Issue 111 (May 2021)
Abstract
Nowadays, the use of tissue culture technique in the production of plant secondary metabolites, such as phenolic compounds, as a natural food additive has become very widespread in the food industry. The aim of this study was to investigate and compare the content of phenolic compounds and antioxidant activity of grapevine Rasha and Qzel Ozum cultivars that were produced by tissue culture under in vitro condition. For this purpose, the terminal buds of grape cultivars were cultured in Murashige - Skoog Medium to produce complete seedlings. Then the methanolic extract was prepared from healthy grapevine leaves and to perform polyphenol composition tests using high performance liquid chromatography with ultraviolet detector, functional groups using Fourier-transform infrared spectroscopy, total phenol content, total flavonoids, total anthocyanins, total carotenoids, acid content, ascorbic acid, free radical scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH), and hydroxyl (OH−). The results showed that the amount of total phenolic compounds, total flavonoids, total anthocyanin and total carotenoids of methanolic extracts of Rasha cultivar were 50.35±0.10, 29.72±0.05, 10.41±0.20, and 1.82±0.50 mg/g, respectively, and in Qzel Ozum cultivar were 23.06±0.31, 20.76±0.15, 7.28±0.15, and 94.94±0.42 mg/g, respectively. Ascorbic acid, DPPH and OH− free radicals scavenging activity in methanolic extracts of Rasha leaves were 1.83±0.04, 25.38±1.52, and 75.04±2.74 %, respectively, and in Qzel Ozum leaves were 0.85±0.01, 18.71±2.05 and 68.96±3.61 %, respectively. As a general result, the results showed that the grape leaves of the Rasha cultivar were more than the grapevine leaves of Qzel Ozum cultivar in terms of all studied characteristics (p <0.05). This study also showed that grape leaves are rich in phenolic compounds and natural antioxidants and have the potential to be used in the food and pharmaceutical industries.
Volume 24, Issue 2 (3-2022)
Abstract
Soil salinity is one of the most important environmental constraints that reduce plant growth and productivity. This study aimed to investigate the effects of various NaCl concentrations on the physiological properties of grape cultivars. NaCl was added at three levels (0, 25, and 50 mM) to Murashige and Skoog medium under in vitro conditions to assess various effects on 21 grape cultivars. Effects of salinity stress were investigated on ascorbate peroxidase, catalase, and superoxide dismutase activities, as well as malondialdehyde, protein, proline, chlorophyll A and B contents, of all samples. The results showed that with an increase in salinity, the amount of antioxidant enzymes, proline content, and protein increased in cv. Rasha, suggesting that it was more tolerant than the other cultivars. Malondialdehyde and Electrolyte leakage accumulation also increased in all cultivars, but this increase was higher in salinity-sensitive cultivars, such as hybrids and wild cultivars than resistant cultivars. During salinity stress, chlorophyll content decreased, and the lowest decrease in chlorophyll content was recorded in cv. Rasha, compared to other cultivars. This research demonstrated that the resistance of cv. Rasha, H6 and H4 to salinity stress was due to its ability to adjust proline, protein content, and antioxidant enzymes.
