Journal of Plant Process and Function

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Adiquate fertilization of fruit trees after harvest will increase fruit yield and quality in coming year. To investigate the effects of potassium sulphate (0, 50, 100 and 150 g) and iron chelate (0, 10, 20 and 30 ml) on fruit quality after harvest, a factorial experiment in randomized complete block design study was performed on apple ̔ Red Delicious ̓ with 3 replications and traits such as firmness, total soluble solids, titrable acidity, anthocyanin and phenole in flesh and skin, total carbohydrate, dry matter percentage, prelim index and concentration of some macro and micro elements of fruit were measured. The Results showed that trees fertilized with 50g of potassium sulphate and 30 ml iron chelate had firmer fruits and more soluble solids. Also the effect of potassium on increasing anthocyanin in fruit skin was more than iron. Despite the decreasing trend in phenol content during storage, potassium Sulphate fertilizer had the greatest effect on increasing the amont of phenol in skin and flesh and even maintaining it during storage compared to the control. On the other hand, with increasing in the amont of iron chelate, the amont of phenols in fruirs decreased. The acidity of fuits in treatments treated with different concentrations of iron was higher than control fruits. Inceasing storage time caused a significant increase in total carbohydrate. Other quality traits decreased were decreased significantly during storage. In Genral, treatment of with 50 and 100 g of potassium sulphate alone or in combination with 10 ml of irone chelate had a good effect on the studied tratis.

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Damask rose is one of the oldest and most valuable rose varieties that to some extent, tolerates water deficiency. However, the selection and identification of genotypes that are more tolerant to drought stress will be effective in development of cultivation of the plant. In this case, an experiment was performed under in vitro conditions using polyethylene glycol at five levels (0, 25, 50, 75 and 100 g L^-1) on four genotypes of Damask rose (Maragheh, Urmia, Pakdasht and Kashan) and the tolerance of genotypes to drought stress was measured based on water relations traits of the plant via response surface method (RSM). Results showed that as the severity of drought stress increased, the percentage of dry matter was increased in genotypes of Maragheh, Urmia and Kashan compared to the control. At concentration of 100 g L^-1 PEG, Maragheh genotype had the highest fresh and dry weight, total chlorophyll, chl a and chl b and the lowest leaf number and height compared to the other genotypes. Carotenoid contents in Urmia and Maragheh genotypes were higher in 100 g L^-1 PEG than other genotypes. As water deficiency increased, leaf water content in Maragheh, Kashan and Urmia genotypes decreased. Maragheh genotype with high values ​​of relative leaf water content, on the other hand, with a decrease in water moisture reduction, relative water loss and saturated water deficiency, showed a better protection mechanism against drought stress than the other three genotypes. After Maragheh genotype, Pakdasht genotype was partially resistance to drought stress up to 75 g L^-1 polyethylene glycol.

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In order to investigate the effects of nanosilicon in salinity stress amelioration in miniature garden rose 'Sanaz' a factorial experiment as a completely randomized design were done with three replications at greenhouse of University of Maragheh in 1399. At the present study for improving in quantitative, qualitative and biochemical traits of miniature garden roses under salt stress (0, 25 and 50 mM NaCl), SiO₂-NPs spray were used at different levels (0, 50, 100, 150 and 200 mg L^-1). Results showed that all measured traits were decreased severely at 50 mM salinity compared to controls and the least amount of each parameter were recorded at 50 mM level of salinity. While SiO₂-NPs spray at 50 mM salinity caused to preserve chlorophyll index and led to increase in the number of plant leaves (62.4%), maximum florescence (55.4%) and variable florescence (more than 3 folded). Also, SiO₂-NPs spray decreased the minimum florescence (44%) at 50 mM salinity. Nanosilicon by stimulating growth and increasing in the activity of the antioxidant enzymes resulted in a decreased lipid peroxidation, malondialdehyde amount and, subsequently decreased oxidative stress in plant cells. Spray of nanosilicon under salinity stress, increased the amount of proline and decreased the oxidative damage to the protein. It seems that according to the present results foliar application of SiO₂-NPs especially at 200 mg L^-1 under salinity stress can be recommended in garden roses. 

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Gerbera is the fifth-cut flower in the world, in terms of economic importance, but it has a short lifespan. One of the main problems with this flower, after harvest, is the decrease in the quality and longevity of the flowers, which is affected by the balance between water absorption and water loss. For this purpose, to investigate the effect of melatonin and GABA on increasing the longevity and quality of gerbera, a factorial experiment was conducted based on a completely randomized design with 3 replications. Vase solutions containing 0.1 and 0.5 mM melatonin, 1 and 5 mM GABA solution, and distilled water were used as a control treatment. The results showed that as the vase life increased, the amount of electrolyte leakage, anthocyanin, malondialdehyde, hydrogen peroxide, and peroxidase enzyme activity increased in all treatments except for the solutions containing 0.1 mM melatonin and 1 mM GABA, while the amount of fresh weight, carbohydrate, flavonoid, total phenol and protein decreased. The maximum decrease in the relative water content of petals and carbohydrates, as well as the maximum increase in the amount of malondialdehyde and electrolyte leakage, was observed on the 10^th day of the 5 mM GABA treatment. The flowers placed in the vase solution containing 0.1 mM melatonin contained the maximum amount of carbohydrate, protein, total phenol and the maximum activity of the peroxidase enzyme. In general, melatonin in both concentrations of 0.5 and 0.1 mM was the most appropriate treatment, which improved the quality of gerbera-cut flowers compared to the control and other treatments. Therefore, according to the hormonal and antioxidant nature of melatonin, it seems that the application of melatonin in low concentrations can be used as a promising technology at the commercial level in the flower industry.

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Physical treatments such as laser, gamma, and beta rays can act as effective factors in increasing the growth and germination of plants. In this research, the effect of different treatments including laser, gamma, and beta rays on germination, growth rate, seedling length, plant dry weight, leaf area, leaf number, and chlorophyll content of pot marigold were investigated. The results showed that seed treated with laser, gamma rays, and beta rays produced significant increases in germination, growth rate, seedling length, plant dry weight, leaf area, leaf number, and chlorophyll content. The number of days until germination under the influence of priming treatments decreased by almost 4 days compared to the control (10 days), which belongs to the three treatments of hydropriming (7.6), gamma rays for 5 minutes (5.6) and beta rays for 15 minutes (6.6). However, the highest percentage of germination belonged to seed treatment with gamma for 15 minutes and beta for 10 minutes, which seems to improve the germination speed is one of the reasons for the above responses. Despite the above results, laser treatment for 15 minutes produced the highest seedling length, which was not significantly different from gamma treatment for 15 minutes. Under greenhouse conditions, beta treatment for 15 minutes caused the maximum stem length, which was not significantly different from laser treatment for 15 minutes. These two treatments had the highest plant dry weight and leaf surface index. According to these results, laser and gamma treatment for 15 minutes and beta ray treatment for 15 minutes have the most improvement in the mentioned traits.