عنوان مقاله [English]
Background and Objectives
Peach is one the most important horticultural crops in Iran. Peach has always been considered for its high nutritional value and its taste in the world. Therefore, improving its quantity and quantity is very important. Today, substances that improve the quality and quantity of the product are very much considered, they are including materials such as hormones, nutrition elements(Ca). Nanoparticles are materials that their size are smaller than 100 nanometers. on the other hand the importance and role of calcium in improving the fruit quantity and quality are interesting for scientists. In this study, the effect of calcium nanoparticles on qualitative and quantitative characteristics of peach fruit was studied.
Materials and methods
This experiment was carried out during the years 2015 - 2017 as a factorial based on a randomized complete block design with three replications in a commercial garden located in Hashtgerd, Karaj. In this experiment, three concentrations 0, 10 and 20 mg/l of calcium chloride nanoparticles, at the time of flower popcorn, flower budding and twenty days after flower opening were sprayed. Then, when the fruits were harvested, the soluble solids, acidity, fruit set, vitamin C content, tissue firmness, calcium content of fruit tissue, fruit length, fruit width and fruit weight were measured.
The results showed that calcium nanoparticles in both cultivars improved qualitative and quantitative traits. Result showed There was not significant difference between treatments and cultivars in flowering time and Calcium nanoparticles cannot have any effect on flowering time and flowering time is affected by the genetics and the environment. Treatments with calcium nanoparticles increased the fruit set rate in this study. The results showed that there was a significant difference between cultivars in length and width of fruit at 1% level, and Early Alberta fruits were larger than Valad Abadi cultivar. There was a significant difference between weight of two cultivars at 1% level and between treatments at 5% level. Early Alberta had a higher fruit weight than Valad Abadi cultivar and no difference observed between the control and treated trees. Increasing in concentration of treatment did not effective on fruit weight. On the other hand the highest amount of TSS, fruit set, vitamin C, calcium content of fruit flesh were observed in 20 mg/l concentration of calcium nanoparticle treatment. in the amount of vitamin C was significantly different between two cultivars at 1% level and between treatments at 5% level. Vitamin C in both cultivars increased with increasing treatment concentration. Among the two cultivars tested, the amount of vitamin C in early Alberta cultivar was higher than the Wald Abadi cultivar, and the highest levels of vitamin C were found in Early Alberta, at a concentration of 20 mg/l. Calcium content in fruit tissue of early Alberta cultivar was more prevalent than Wald abadi cultivar and the most effective treatments were treatment of calcium nanoparticles with concentration of 20 mg/l Calcium nanoparticles in the Valad Abadi cultivar increased the firmness of the fruit tissue, while there was no significant difference among treatments in Early Alberta cultivar. This difference can be attributed to the difference between genetically basis of the two cultivars. Calcium nanoparticles treatments did not affected the fruit length of Valad Abadi cultivar. There was no significant difference between treatments and control, while in Early Alberta, with increasing concentration of calcium nanoparticle, fruit length increased. Calcium nanoparticles treatment increased the weight in both cultivars while there was no significant difference between the concentration of 10 and 20 mg/l of calcium nanoparticles.
Calcium caused a change in the enzymatic activity of certain enzymes involved in metabolism and effective enzymes in nitrate absorption and can improve fruit quality and quantity. Calcium was considered as a binding agent between cell walls which result in higher fruit firmness and calcium nanoparticles can improve shelf life in peach fruit. calcium increases the strength of the middle blade and the cell wall by creating calcite packets, and decreases the activity of the polygalacturonase enzyme's. Calcium also reduces respiration, reduces the production of ethylene, and reduces the activity of the polyagalacturonase enzyme from appetite and softness of the fruit. Calcium increases the activity of antioxidant enzymes such as superdioxidase, catalase and peroxidase and calcium treatment can improve fruit quality and quantity. Our result showed calcium nanoparticles are effective in improving peach fruit quality and quantity.