s.h. mirdehghan

The present study was conducted to investigate the effects of two concentrations of Aloe vera gel (7.5 and 15%) on quantitative and qualitative characteristics of lime during storage time (20, 40, and 60 days). The study was performed as a factorial experiment in a completely randomized design with four replications. After dipping (5 minutes) and drying, the fruits were packaged in low-density polyethylene containers and transferred to cold storage at 4±1°C and 85±2% relative humidity. The results showed a decrease in fruit sourness and aroma and an increase in fruit bitterness during storage. The highest rate of chilling injury and decay belonged to the control. Aloe vera gel 15% had the lowest fruit bitterness (30%), decay, and malondialdehyde compared to the control on day 60 of storage. The Aloe vera gel enhanced peroxidase activity as an antioxidant enzyme and decreased defense-related enzymes such as phenylalanine ammonia-lyase activity. The maximum vitamin C was related to Aloe vera gel 15%. According to the results, Aloe vera gel, could not effectively control weight loss and firmness. During 60 days of storage, compared to the control, Aloe vera gel 15% increased Chroma index (2.07%) and vitamin C (26.37%), and prevented decay (100%), chilling injury (25.75%), bitterness (42.85%), and malondialdehyde (35.80%) of lime fruit.

Drought stress in tomatoes reduces fruit quality and yield, also fall leaves and cause of blossom rot. It has been reported that drought stress reduces cell division and causes the stomata to close, followed by a decrease in the flow of carbon dioxide to the mesophyll cells of the leaf. Several methods have been proposed to overcome the drought stress in tomato plants, which can be mentioned the use of drought tolerance genotypes, genetic engineering to identify drought resistant genes and transfer them to sensitive plants, as well as the use of tolerancet rootstocks. It has reported that type of rootstock can effected on tolerance of tomato plants to drought stress. For this reason, the present study was conducted to investigate the effect of wild eggplant rootstock on the drought tolerance of two tomato cultivars.

In order to find the effect of the wild eggplant rootstock on the tolerance of two tomato cultivars, a factorial experiment was conducted as completely randomized design with two factors. Factors were included irrigation period three levels of 3 (control), 6 and 9-day and grafting combination at 6 levels involved non-grafted Dafnis, non-grafted Isabella, self-grafted Dafnis, self grafting Isabella, Isabella grafted on wild eggplant rootstock (S. torvum), and Dafnis grafted on wild eggplant rootstock. The plants were exposed to drought for 54 days. At the end of experiment growth and physiological parmeters including leaf specific, plant height dry weight of shoot as well as photosynthesis parameters, RWC and plant nutrients were measured. The amount of leaf proline was measured according to Paquin and Lichasur methodusing a spectrophotometer at a wavelength of 515 nm. The phenolic compounds of the leaves were measured at a wavelength of 725 nm using a spectrophotometer (Isfendiyaroglu and Zeker, 2002). Also, the membrane stability index (ion leakage percentage) was measured according to Lutts et al.'s method (Lutts et al., 1996).

The results showed that with increasing irrigation period decreased the most of vegetative parameters, photosynthesis pigments, and mineral nutrients, so that, the highest value was showed at the 3-day irrigation period and the lowest value was at the 9-day irrigation period. Shoot weight decrese is probably due to morphological changes in plant roots, which is a plant response to drought stress. The results also showed that the interaction of irrigation period and grafted combination on some vegetative and ecophysiological parameters was significant. The lowest dry weight of shoot was observed at 9-day of irrigation period in plants of Dafnis grafted on torvum rootstock., Tthe highest dry weight root volume, leaf potassium and phosphorous concentration were at the 3-day irrigation period in self-grafted Dafnis plants.The results also showed that the amount of phenolic compounds in plants of Isabella grafted on torvum rootstock was the highest in 9 days irrigation period which may be due to the rootstock effect on the synthesis of these compounds in the scion. According to the results, the concentration of leaf magnesium in non-grafted plants increased with the increase of the irrigation cycle from 3 days to 9 days, althougth no significant difference was observed between self-grafted and non-grafted plants. In the 9-day irrigation period, the highest concentration of leaf magnesium was observed to non-grafted Daphnis plants, which was significantly different from other grafting combinations compounds except Daphnis self-grafted plants.

The results of the present study showed that drought stress had the greatest effect on dry matter, and the amount of photosynthetic indices and pigments in tomato plants. Based on the results of the present study, it was found that the most of the reduce vegetative and physiological parameters was observed in Daphnis cultivar grafted on the thorum rootstock, were significantly reduced compared to self-grafted or non-grafted plants, which it was due to the dwarfing effects of this rootstock or grafting incompatibility. According to the results of the present study, it can be postulated that in drought stress Isabella cultivars grafted on the wild eggplant rootstock had more growh than other combination grafting. Hence it proposed more studies in this case.

Pomegranate is a popular fruit, rich in antioxidants and minerals but sensitive to postharvest storage. The efficiency of 5 and 10 mM γ-Aminobutyric Acid (GABA) combined with 0.5% carnauba wax as edible coating was investigated on extending the cold storage life of pomegranate fruit (Cv. Malas Saveh) after 45 and 90 days. Coatings maintained fruit freshness, inhibited the chilling injury symptoms, reduced peel malondialdehyde formation (minimum of 0.74 nM g-1), reduced loss of aroma/taste, and increased aril antioxidant activity (maximum of 94.9%). Aril anthocyanin content was more stable in 5 mM GABA coated than uncoated fruits. However, the coatings caused more weight loss on 45th day (11.0% in 10 mM GABA and 8.3% in the control). This parameter was similar in coated and uncoated fruits after 90 days. Aril phenolic content in coated fruits was higher on 90th day but not on 45th day (maximum of 0.08 mg.100g-1 in the control on day 45). Aril lightness increased in the control sample on 45th day while coated fruits were more similar to harvest time. After 90 days, the control and treated samples were similar. The color scales (a*, b*, and Chroma) values of peels and arils declined by storage without any significant effects of coatings. Peel and aril Hue did not change by storage time or coatings. Results suggested some benefits of coatings for retaining the postharvest quality of pomegranate fruits.

In order to compare the effect of three nutrient solution replacement methods in an NFT system and pruning on hot pepper, a factorial experiment was conducted. Factors included nutrient solution replacement method (complete nutrient replacement, partial nutrient replacement according to EC, and partial nutrient replacement according to plant requirements) and pruning (pruning and non-pruning). Results showed that the highest vegetative growth was recorded in plants fed by complete replacement of nutrient solution, while plant fed based on EC showed the lowest vegetative growth and nutrients concentration. Leaf Chlorophyll a (Chl a) and Total Chlorophyll (TChl) decreased in plants fed according to EC control and plant requirements compared to complete replacement of nutrient solution. All these traits were higher in non-pruned plants than in pruned plants. Fruit yield decreased in plants fed based on nutrient solution EC and plant requirements, and pruning treatment decreased these traits, but the highest single fruit weight belonged to pruned plants fed based on plant requirements. The highest fruit carotenoid content, Total Soluble Solids (TSS), and vitamin C were recorded in plants fed according to nutrient solution EC, and these traits were higher in the pruned plants compared to non-pruned ones. The results also showed that pruning caused a reduction in plant growth and fruit number, therefore, it is not recommended for hot pepper cv. Sentela.

Fresh pistachio nuts undergo biochemical and physiological changes after harvest and postharvest and as a result، it has a short shelf life. The purpose of this research is to study the effects of packaging type and edible coating on quality and increasing the shelf life of fresh pistachio nut. Therefore، two separate experiment were conducted and in first one the individual fresh pistachio were dipped in different concentration of aloe vera gel (0 (control)، 25، 33، 50 %) and also Nanocid at 80 and 100 mgl-1 and kept at 4±2°C for 40 days. In second experiment، to compare the plastics produced through Nano technology and usual plastics (nylon)، fresh pistachio nut were packed and stored in mentioned condition. Weight loss، pistachio quality appearance and its marketability were examined every 5 day- interval and fat and soluble carbohydrate at the end of storage. The results showed that Nano films comparing to control were useful significantly (p≤0. 01) in controlling the weight loss and keeping fresh pistachio’s appearance. Also weight loss and fresh pistachio browning were lower in aloe vera gel treatments and the best results (higher soluble carbohydrate and appearance) come from 25% aloe gel compared to control.

In this study, fresh pistachio of 'Ohadi' and 'Akbari' cultivars expose to the UV-C radiation with a wavelength of 0, 3, 6 and 12 KJ/m2, then located at temperature of 1 ± 3 degrees Celsius for 45 days. Properties or attributes, including weight loss, stiffness and sensory evaluation of fresh pistachio after 20 and 45 days storage were measured. Results showed that pistachio nut weight losses (28.77%) was less than the amount of weight loss of pistachio clusters (33.39%). UV-C 6 kj/m2 treatment showed lowest weight loss than other treatments