اثر کاربرد اسید سالسیلیک، ضد‌یخ و روغن سویا بر میزان رنگیزه‌ فتوسنتزی، مادگی سالم و درصد تشکیل میوه گیلاس رقم "سیاه تکدانه مشهد" در شرایط تنش سرما

Abstract
In order to investigate the effect of the use of salicylic acid, antifreeze and soybean oil on the cold resistance of sweet cherry flower of the " Siah Tekdane Mashhad " a factorial experiment was conducted in the form of a randomized complete block design with 3 factors each at 3 levels (salicylic acid : 0, 1.5 and 3 mM), (natural antifreeze Thiofer: 0, 2.5 and 5 parts per 1000) and (soybean oil: 0, 2.5 and 5 parts per 1000)} and in 4 repetitions in A commercial garden located in Sarein city was implemented in 2018 and 2019. The percentage of cherry fruit formation as well as the amount of chlorophyll a, b and total pigments were significantly influenced by the interaction of salicylic acid and salicylic acid. Also, the amount of total chlorophyll was influenced by salicylic acid*soybean oil interactions. The comparison of the averages showed that the highest percentage of healthy females (69.25%) was obtained in the treatment combination of 1.5 mM salicylic acid*2.5 concentration (parts per thousand) of soybean oil*5 concentration (parts per thousand) of antifreeze. which had no significant difference with the treatment of 3 mM salicylic acid at a concentration of 2.5 (parts per thousand) of soybean oil and at a concentration of 5 (parts per thousand) of antifreeze. The highest concentration of chlorophyll a (14.87 mg/g fresh weight) was observed in 2018 crop year and foliar spraying of 3 mM salicylic acid.
Introduction
With the changes in the earth's climate in recent years, late spring colds have become endemic in many regions of the country, causing great damage to plants and agricultural products every year (Karmi, 2014). Environmental stresses in plants cause morphological, physiological and molecular changes, which have a negative effect on growth and yield (Javadian et al, 2010). Among the abiotic stresses, cold stress is very important due to the decrease in yield and the limitation in the geographical distribution of plants (Matuk et al, 2008). The damage caused by cold in the sensitive stages of plant growth and development is one of the important factors in reducing the yield of plants all over the world (Yang et al, 2011). has increased, so that only during the 9 months of 2015, out of the total 9610 billion tomans of damage to the agricultural sector, 5733 billion tomans (about 60%) was related to frost. . It should be noted that flower buds in the bud stage may tolerate up to -7 degrees for 30 minutes, while open flowers generally die at temperatures below -2 degrees. Small fruits are much more sensitive to cold after the petals fall. Therefore, operations that cause a delay in bud growth can have a significant impact on reducing damage caused by spring cold. Therefore, any factor that delays the development of buds in the spring can make them immune to the spring cold (Mir Mohammad Meibdi and Takesh Esfahani, 2013). Many measures can be taken for this purpose. One of the solutions is to use growth regulators such as jasmonic acid, salicylic acid and alar, which can be effective in reducing spring cold damage. The mechanism of delaying flowering by using growth regulators is stopping cell division and delaying the development of flower buds and reducing growth. Also, the reduction of the effect of low temperature in the removal of stagnation, the reduction of the sensitivity of flower buds to growth temperatures and the increase of the resistance of flower buds to cold due to the accumulation of large amounts of sorbitol and sucrose have been mentioned (Moin Rad, 2008). Another way to reduce spring cold damage is to use natural antifreeze (Natural Plant Antifreez). These materials either act as a mechanical barrier to prevent the formation of ice crystals on sensitive plant tissues or activate the cold resistance systems in the plant (Wilson, 2001). Natural antifreeze lowers the freezing point in plants (7-8 degrees) and thus helps to protect plants from cold and freezing.

Methodology
In order to investigate the effect of using salicylic acid, antifreeze and soybean oil on the cold tolerance of single-seeded black cherry of Mashhad, a factorial experiment was conducted in the form of a randomized complete block design with three factors of salicylic acid (0, 1.5 and 3 millimolar), natural antifreeze Thiofer (0, 2.5 and 5 parts per 1000) and soybean oil (0, 2.5 and 5 parts per 1000) in 4 replications during 2018-2019 in a commercial garden It was implemented in the village of Kurde Deh, located in Sarein city. These treatments were carried out in the form of foliar spraying in three times (the time of swelling of buds, buds and full opening of flowers). 72 hours after the application of the last stage of the experimental treatments, the branches containing flowers were taken from the trees in the garden and were transported in plastic bags with a flask containing ice to the physiology laboratory of the department of horticulture and the central laboratory of Mohaghegh Ardabili University. The branches were wrapped in wet cloths and wrapped in aluminum foil and then placed in plastic bags. Plastic bags containing branches were treated in an ethylene-glycol bath for 24 hours at a temperature of -4°C. The samples were removed from the incubator and placed at room temperature of 21 ± 1°C for 24 hours and then the samples of each treatment were evaluated.

Conclusion
According to the results of the data variance analysis table, the percentage of healthy females was significant under the influence of the simple effect of year and the interaction effect of salicylic acid*oil*Tiofer antifreeze. The percentage of cherry fruit formation as well as the amount of chlorophyll a, b and total pigments were significantly affected by the interaction of salicylic acid and salicylic acid. Also, the amount of total chlorophyll was influenced by salicylic acid*soybean oil interactions. The amount of carotenoid was also affected by the interaction effect of salicylic acid and soybean oil. The highest concentration of chlorophyll a (14.87 mg/g fresh weight) was observed in 2018 crop year and foliar spraying of 3 mM salicylic acid, which with 1.5 and 3 mM salicylic acid foliar treatments in 2019 in a The statistical group was shared (Figure 2). By increasing the concentration of soybean oil foliar spraying, the concentration of chlorophyll a pigment decreased, so that the control treatment (spraying with water) with a concentration of 14.64 mg/g fresh weight was the highest and the foliar spraying treatment of 3 mM salicylic acid with a concentration of 13.27 mg/g of fresh weight pigment had the lowest amount of chlorophyll a (Figure 3). Salicylic acid increases the rate of total photosynthesis by increasing the activity of Rubisco enzyme and increasing chlorophyll (Sing and Usha, 2003). The increase of chlorophyll and carotenoid content in the conditions of salicylic acid solution-spraying in barley plant (Hordeum vulgare L.) has also been reported and the result of this has been considered to be an increase in the speed of photosynthesis (El-Tayeb, 2005); Therefore, it can be concluded that maintaining the concentration of chlorophyll in difficult environmental conditions helps the stability of photosynthesis and reduces the damage caused to the plant in environmental stress and increases the yield of the plant.
The highest accumulation of total chlorophyll (20.39 mg/g fresh weight) was observed in cherry leaves in the crop year 2018 and foliar spraying with 3 mM salicylic acid, which was observed with 1.5 and 3 mM salicylic acid foliar treatments per year. 1399 crops were in a common statistical group, the lowest total chlorophyll accumulation (18.09 mg/gram of fresh weight) was observed in 1398 crop year and no salicylic acid spraying (spraying with water solution) was observed (Figure 6). . The comparison of average data indicates that in the mutual treatment of salicylic acid*soybean oil, the highest accumulation of total chlorophyll (21.11 mg/g fresh weight) is in the foliar treatment of 1.5 mM salicylic acid with no solubility. Spraying with soybean oil (spray solution with water) was achieved (Figure 7). A significant increase in chlorophyll and carotenoid content was observed in the conditions of salicylic acid dissolution in this research, and this is the result of increasing the speed of photosynthesis. It can be concluded that maintaining the concentration of chlorophyll in difficult environmental conditions helps the stability of photosynthesis in these conditions and causes the reduction of damages caused to the plant due to environmental stress.