Aflatoxins are secondary metabolites produced by Aspergillus flavus, A. parasiticus, A. tamari, A. bombycis and A. nomius species. Relative humidity (RH) is one of the most important parameters influencing the development of aflatoxins in pistachio orchards by Aspergillus species. The type of irrigation system affects density and frequency of the Aspergillus species in the soil. In the current study, to evaluate fungus population density three irrigation treatments (flood, drip-surface, and subsurface irrigation) were applied. In order to investigate the population density of Aspergillus flavus in different irrigation systems, sampling was done from soil and kernels of Shahpasand cultivar at Damghan's Pistachio Research Station under various types of irrigation systems implementation. The samples were inoculated on AFPA medium using serial dilution method. The results indicated that the population density of A. flavus ranged various in pistachio kernels and soils between different types of irrigation system. Through subsurface irrigation, the population density of fungal colonies was significantly at the lowest level. The results showed that the use of modified adopted subsurface irrigation system had been effective in reducing soil surface moisture and led to decrease of population density in comparison with the conventional surface drip irrigation. Manuscript profile

The study was conducted to evaluate the pomological attributes and chemical composition of 35 pistachio (Pistacia vera L.) genotypes, including fifteen wild-types and twenty of the important cultivar pistachios from Iran. The results revealed that cultivar pistachios in terms of important characters such as the split nuts (78.57%), blank nuts (6.96%), 100-nuts weight (118.86 g), and size (20.84 mm) were superior to wild cultivars. Higher percentages of thesplitnutswere observed for ‘Akbari’ genotype (92.81%), and the lowest rate of blank nuts was observed in ‘Fandoghi 48’ (2.84%). Pistachio kernel is rich in nutrients which is almost the same in wild and cultivar genotypes. The mean N, P, K, Mg, Ca, Na, Fe, Zn and Mn values of the pistachio kernels studied were 3.39%, 0.52%, 0.88%, 0.14%, 0.27%, 0.08%, 33.20 μg g-1, 22.40 μg g-1 and 7.38 μgg-1, respectively. The ranges of protein and oil content were 13.70-23.63% and 45.81-55.49%, respectively. According to the results, there was a considerable difference in physical and pomological properties among wild and cultivar pistachio nuts, while there was less difference in oil content and nutrition quality between them. Manuscript profile

This research was conducted to determine the effect of salicylic acid on the drought tolerance of three pistachio (Pistacia vera L.) rootstocks. The treatments were included three irrigation levels (Control: 100 % ETc, medium stress: 65% ETc, and severe stress: 30% ETc), three pistachio rootstocks, and three salicylic acid concentrations (0, 1, and 3 mM). The salicylic acid solution was once applied as a foliar spray, starting water stress, and irrigation treatments continued for 75 days. Results showed that P. vera ‘Badami Zarand’ was less affected by water stress treatments than the other seedling rootstocks. Among the rootstocks studied, the highest photosynthesis rate (6.55 µmol CO2 m-2 s-1) was obtained in P. vera ‘Badami Zarand’ under severe water stress (30 % ETc) and 1 mM salicylic acid application. The lowest photosynthesis rate (2.75 µmol CO2 m-2 s-1) was observed in P. vera ‘Sarakhs’ under severe water stress (30 % ETc) and 3 mM salicylic acid treatment. In addition, the highest relative water content (66.16%) and the lowest ion leakage (33.29%) were obtained in ‘Badami Zarand.’ The 1 mM salicylic acid application effectively reduced the negative effects of water stress. According to the results, P. vera ‘Badami Zarand’ showed a better response to salicylic acid under stress conditions, and the highest photosynthesis, relative leaf water content, dry weight of organs (leaves, shoots, roots), and the lowest ion leakage under drought stress belonged to this rootstock. Manuscript profile

Drought is one of the main important adverse environmental events, certainly has an impact on plant growth and development. Pistachio is cultivated in areas where soil water deficits and salinity conditions are higher than normal. In most orchards, deficit irrigation is a common practice. There is only limited understanding of the physiological mechanisms pistachio uses to survive in drought. Many adaptive strategies have been developed in plants for dealing with water stress. The objective of the present study was to evaluate the effect of drought stress on the photosynthetic, physiological and biochemical parameters in one-year-old seedlings of 12 pistachio hybrids. Therefore, a greenhouse experiment was carried out to assess the effects of two drought stress treatments (drought stress and full-irrigation) for 40 days with a subsequent two weeks’ recovery period and several parameters (pigments (total chlorophyll, anthocyanins and carotenoids), internal CO2 concentration (Ci), chloride (Cl-) ions and fluorescence parameter) were evaluated at four different times (beginning, middle and end of stress and then recovery). After the end of the stress period, the seedlings were irrigated for two weeks. Results revealed that the drought stress treatments led to a change in the studied parameters and the mechanism of drought tolerance was variable at different times. Pistacia atlantica hybrid, P. vera “Sarakhs” and P. vera “Shasti” hybrid rootstocks had the highest water use efficiency; P. vera “Sarakhs” hybrid, P. vera “Khanjari” hybrid and P. vera “Badami” hybrid had the highest Cl- and mesophyll efficiency. P. atlantica and P. vera “Khanjari” had the highest anthocyanins and carotenoids. P. vera “Shasti”, P. vera “badami”, P. mutica and P. mutica hybrid rootstocks have been able to withstand drought stress by increasing the amount of K+ ion and maintaining gas exchanges. The results also showed that the response of the rootstocks to rehydration was different. Seedlings that recovered well after rehydration had a higher tolerance threshold. The “Khanjari” cultivar was recovered better than the others. Manuscript profile

Pistachio is one of the most important horticultural crops in Iran. There is a unique role for amino acids in the plant response to stressful conditions, and special physiological role for Arginine (Arg) compared to other amino acids. The effects of this compound were investigated on vegetative and reproductive characters of bearing pistachio trees of ‘Ahmad-Aghaei’. The experiments were done as a factorial based on RCBD with four concentrations of Arg (0, 100, 200 and 300 µM) and three spraying stages (post harvest, flower buds swollen and flowering). Based on the results, Arg improved the vegetative and reproductive characters. Arg increased length and diameter of shoot, leaf area, the number of floweringbuds, the number of nuts in cluster, fresh weight of cluster, nut splitting (%) and ounce, and decreased flower buds abscission percent and blankness. Arg also significantly increased photosynthetic pigments (chlorophyll a and b and total chlorophyll) in bearing pistachio trees. The best concentration of Arg was 200 µM applied of the flowering stage, but the strongest effect on the number of nut in cluster, fresh weight of cluster and blankness were observed when spraying at the flower bud swollen stage. Manuscript profile

UCB-1 (Pistacia atlantica × P. integrima) is a commercial rootstock for pistachio in some pistachio plantations across the world. This rootstock is very new in Iran and recently, it has been used commercially in some plantations due to its high growth. Propagation of this rootstock by tissue culture results in many limitations such as shoot tip necrosis (STN) and a low proliferation rate. Therefore, any process that leads to improve the proliferation rate and feature will be used in commercial propagation of this rootstock. Nanotubes are widely used in in vitro cultures. For this reason, we used different concentrations of carbon nanotubes (0, 50, 100, 150, 200 µg/l) and benzyladenine (0, 0.5, 1, 1.5 and 2 mg/l) to improve the proliferation rate and qualitative indices. The results showed that using carbon nanotubes concentration of 200 µg/l with 2mg/l of benzyladenine (BA) led to maximum proliferation (4 microshoots per explant), maximum shoot length (3.68 cm) and minimum STN (8%) and vitrification (this isn’t a word?) (0 %) percentage. Manuscript profile

A greenhouse experiment was conducted to evaluate the freezing damage in some pistachio rootstocks by ion leakage and pH changes of leaked solution. A factorial experiment was carried out in randomized block designs (RBD) with three factors: Temperature (A) including 4 ̊C, 0 ̊C, -2 ̊C, -4 ̊C, -6 ̊C, Time (B) including 3, 12, 24h , and Rootstock (C) including P. vera cv 'Badami Zarand' (V13) and 'Sarakhs' (S5), P. mutica (M1)and P. atlantica (A7). For this, one-year-old seedlings were kept at these five temperatures in incubator for 2 hours. Then in the first 24 hours in three hour intervals and during four days, EC and pH in leaked solution were measured daily. After four days the seedling samples were autoclaved at temperatures 105°C for 4 minutes to destroy all cell membrane. EC and pH of remaining solution were measured again and the percentage of ionic leakage was calculated. The results showed that the best time to evaluate the pH and ionic leakage was 24 hours after incubation of samples. Based on the results, ionic leakage dramatically increased with decreasing temperatures from 0°C to -6°C, while pH of leaked solution had no significant difference in 0°C and 4°C temperature treatments. When temperature reduced from 0°C to -6°C, like ionic leakage, pH greatly reduced. So the pH of the leaked solution could be an appropriate tool to study the freezing damage of pistachio rootstocks. Based on the results of pH and ionic leakage, P. mutica and P. atlantica were the most frost tolerant and sensitive rootstocks of this experiment, respectively. Manuscript profile

The aim of this study was to identify the effect of Spermine and Salicylic acid on several growth parameters, such as shoot length, shoot fresh and dry weights, amount of protein and carbohydrate, of Badami and Qazvini pistachio cultivated variety under copper stress. The experiment design was completely randomized with three replicates per treatment and four levels of copper (o.5, 30, 45, 60 µM), one level of SA (o.5mM) and one level of Sp (o.5 mM). The excess copper significantly reduced the fresh and dry weight of the shoot and amount protein in pistachio plants. The carbohydrate was also increased as a response to the increase of copper. However, the damage was higher in Qazvini pistachios compared to Badami pistachios. The SPM and SA treatments increased the shoot length and root and shoot fresh weights as well as the amount of protein and moderated the carbohydrate in the pistachio plants under copper stress. The carbohydrate in plant was also increased. It was concluded that SA and SPM could be used as a potential growth regulators to improve copper stress in pistachio plants. Manuscript profile

One of the most important crop plants is potato. Plant tissue culture is a very important technology in plant cultivation. In this investigation, the biochemical characterizes are investigated of potatoes cultivated by the tissue culture method. The lateral and apical buds were separated from the stem. They were sterilized and cultured in Murashige and Skoog culture medium. The concentrations of salt (0, 25, 50, 75 and 100 mM) have been used for salinity. After the growth of buds, the leaves were sampled and the chlorophylls, proline, sugars, protein, and antioxidant enzymes activity such as catalase, superoxide dismutase, guaiacol peroxidase, glutathione reductase and ascorbate peroxidase were evaluated. The results indicate that salt decreased protein and chlorophylls content. Sugars content and fresh weight have also been reduced with salinity, but the content of proline, malondialdehyde, and hydrogen peroxide were increased under salinity stress. Phenolic compounds, anthocyanin content, and antioxidant enzymes activity increased up to 50 mM salinity, but they decreased above this concentration. According to these results, it can be suggested that Agria cultivar potatoes are not recommended in salinity higher than 50 mM. Manuscript profile