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Background Flower development and sufficient fruit set are important parameters with respect to walnut yield. Knowledge about flowering genes of fruit trees can help to conduct better molecular breeding programs. Therefore, this study was carried out to investigate the expression pattern of some flowering genes ( FT , SOC1 , CAL , LFY and TFL1 ) in Persian walnut (cv. Chandler) during the growing season and winter dormancy. Results The results showed that walnut flower induction and initiation in Shahmirzad, Iran occurred in early June and late September, respectively. After meeting chilling and heat requirement, flower differentiation and anthesis occurred in late-March and mid-April to early-May, respectively. Study of flowering gene expression showed that the expression of the FT gene increased in three stages including before breaking of bud dormancy, from late March to late April (coincided with flower differentiation and anthesis) and from late May to mid-June (coincided with flower induction). Like FT , the expression of SOC1 gene increased during flower induction and initiation (mid-May to early-August) as well as flower anthesis (mid-April to early-May). LFY and CAL genes as floral meristem identity genes are activated by FT and SOC1 genes. In contrast with flowering stimulus genes, TFL1 showed overexpression during winter dormancy which prevented flowering. Conclusion The expression of FT gene activated downstream floral meristem identity genes including SOC1 , CAL and LFY which consequently led to release bud dormancy as well as flower anthesis and induction. Also, TFL1 as a flowering inhibitor gene in walnut showed overexpression during the bud dormancy. Chilling accumulation reduced TFL1 gene expression and increased the expression of flowering genes which ultimately led to overcome dormancy.

Pomegranate is a perishable superfruit with important human health-promoting phytochemicals. The use of cold storage is inevitable for its long-term preservation. As pomegranate is sensitive to temperatures below 5°C, it is therefore necessary and worthwhile to introduce a postharvest technique that is safe, applicable, and commercially acceptable to maintain the fruit quality under a cold storage condition. The efficacy of intermittent warming (IW) in the form of a single warming period (1 day at 20°C with 70% relative humidity (RH) before returning the treated fruit to storage) during the cold storage of ‘Rabab-e-Neyriz’ pomegranate (70 days at 2 ± 0.5°C and 90 ± 5% RH) was evaluated. To find the best treatment time, warming was performed at 4 temporary interruption points in storage (after 15, 25, 35, or 45 days of storage). For each interruption date, the treated fruit were compared to the controls twice, once immediately after treatment and once at the end of the storage period. It was founded that a single warming period at the right time during cold storage (before irreversible damage occurs) activated multiple mechanisms and physiological responses in pomegranate fruit peel that are significantly responsible for alleviating the severity of chilling damage to this commodity. In other words, warming on the 15th day was the most efficient treatment, resulting in better preservation of unsaturated fatty acids from peroxidation, lower malondialdehyde (MDA) production, and preservation of the unsaturated/saturated fatty acids (UFAs/SFAs) ratio (membrane integrity index) in the peel during storage and lower chilling injury symptoms. Moreover, the content of spermine (Spm) and putrescine (Put) (as important antioxidants acting as membrane safety agents) was significantly increased immediately after treatment, followed by a continuous increase in Spm and a higher level of Put compared to control until the end of storage.

Jujube (Ziziphus jujuba) is a species particularly prone to erratic fruit set. Several causes such as pollen germination and tube growth involve in this behaviour. Thus, the present research aimed to evaluate and compare of pollen grains germination and tube growth of ten Iranian jujube cultivars on in vitro condition. A factorial trial based on completely randomized design with five replications was carried out. The pollen grains were collected from un-opened-flowers of Al-Ghour’, ‘Bardaskan’, ‘Doroh’, ‘Gazik’, ‘Ghom’, ‘Giouk’, ‘Kangan’, ‘Kalkestan’, ‘Magham Sari’ and ‘Noghab’ cultivars at balloon stage. This study showed that there were significant differences among the cultivars in all measured factors. The highest percentage of pollen grains germination was observed for ‘Gazik’, followed by ‘Bardaskan’, while the lowest was in ‘Al-Ghour’. The percentage of pollen grains germination increased with the increasing time of incubation period up to 36 h. Also, flowering times are found to be effective in germination of pollen grains, which 1 flash had highest percentage of germination of pollen grains than in comparison to other flowering times. The results also showed that the mean time germination varied from 24.52-25.92 h, mean hourly germination from 0.67-1.55, hourly germination speed from 0.64-1.48 and coefficient of velocity of germination of pollen grains from 0.058-0.061. The length of pollen tube was found between 44.4 and 624.8 µm. These data demonstrated that cultivar is the main factor determining pollen grains germination and tube growth in jujube, which this important information can be useful for selection of superior desirable jujube genotypes for bringing to commercial cultivation.

Jujube (Ziziphus jujuba) is a species particularly prone to erratic fruit set. Several causes such as pollen germination and tube growth involve in this behaviour. Thus, the present research aimed to evaluate and compare of pollen grains germination and tube growth of ten Iranian jujube cultivars on in vitro condition. A factorial trial based on completely randomized design with five replications was carried out. The pollen grains were collected from un-opened-flowers of Al-Ghour’, ‘Bardaskan’, ‘Doroh’, ‘Gazik’, ‘Ghom’, ‘Giouk’, ‘Kangan’, ‘Kalkestan’, ‘Magham Sari’ and ‘Noghab’ cultivars at balloon stage. This study showed that there were significant differences among the cultivars in all measured factors. The highest percentage of pollen grains germination was observed for ‘Gazik’, followed by ‘Bardaskan’, while the lowest was in ‘Al-Ghour’. The percentage of pollen grains germination increased with the increasing time of incubation period up to 36 h. Also, flowering times are found to be effective in germination of pollen grains, which 1 flash had highest percentage of germination of pollen grains than in comparison to other flowering times. The results also showed that the mean time germination varied from 24.52-25.92 h, mean hourly germination from 0.67-1.55, hourly germination speed from 0.64-1.48 and coefficient of velocity of germination of pollen grains from 0.058-0.061. The length of pollen tube was found between 44.4 and 624.8 µm. These data demonstrated that cultivar is the main factor determining pollen grains germination and tube growth in jujube, which this important information can be useful for selection of superior desirable jujube genotypes for bringing to commercial cultivation.

The pattern of walnut flowering varies depending on genetic and environmental factors. This research was carried out to study the patterns by which pistillate flowers develop as a result of applying gibberellic acid (GA3). To study the effect of gibberellin on flowering, we used a factorial test. Factor A was the diameter of the tree trunks, and three levels were considered (10 to 12 cm, 12 to 14 cm and 14 to 16 cm). Factor B was comprised of four levels of GA3 (0, 50,100 and 200 mg/lit). Different levels of GA3 were sprayed twice on the ‘Chandler’ cultivar, i.e. 2 and 4 weeks after flowering. Also, a new (without using a microtome or scanning electron microscopy) method was used to study the development of pistillate flower buds.  Different stages of development included induction, initiation and differentiation of the pistillate flower bud which were observed respectively in late May, early June, September and March. The results of GA3 application showed that GA3 treatment can alter the flowering pattern of walnut. GA3 application significantly increased the number of male flowers, total flowers, and male: female flower ratio per branch. The number of female flowers increased as the diameter of the tree trunk increased. The highest number of female flowers (62.3) was observed in trees with trunk diameters between 14-16 cm and when GA3 was applied at 100 mg/liter. Also, a linear regression model was used in order to find a relationship between GA3 levels and the diameter of the trunk with flowering pattern.

Here, the physical and chemical properties of date fruits were improved using three types of edible coating: pectin (P), methyl cellulose (MC) and olive oil. Dry and semi-dry date fruits were heated at 50 °C for 3 h and then treated with various coating formulations. The date fruits were drained, dried and stored for 3 and 6 months at room temperature in zip-lock plastic bags and brown paper bags. The experiments led to the measurement of fruit moisture percentage, total soluble solids (TSS), firmness, total tannin content and total phenolic content (TPC). According to the results, the coated date fruits generally contained higher percentages of moisture than the untreated fruits. The pectin-based coating provided the best potential among other coatings for extending the shelf life of date fruits. Also, zip-lock plastic bags considerably extended the shelf life of date fruits. The edible coatings substantially benefited several cultivars of date fruits, i.e. ‘Khadrawy’, ‘Estamaran’, ‘Hallawy’, ‘Piarom’ and ‘Zahidi’. The TSS contents of fruits were not significantly affected by the coating treatments, but using paper bags for the storage of date fruits led to a better maintenance of TSS percentage in fruits, as compared to the use of plastic bags. Date fruits became firmer as a result of using olive oil as the coating material, whereas the use of pectin reduced the fruits firmness. The lowest tannin content was recorded in fruits coated with MC, whereas the highest content was measured in those coated with pectin and olive oil. The ‘Estamaran’ and ‘Zahidi’ cultivars showed the highest and the lowest TPC, respectively. A better maintenance of TPC was observed when storing the date fruits in plastic bags, as compared to the use of paper bags. Therefore, edible coatings and plastic bags can extend the shelf life of dry and semi-dry date fruits effectively when storing them at room temperature for 3 months.

Limited shelf life of pomegranate makes its cold storage necessary. On the other hand, it encounters chilling injury (CI) incidence at temperatures below 5 ºC. Intermittent warming (IW), known as one or more warming periods during cold storage, is a beneficial postharvest treatment for keeping fruit quality. Pomegranate ‘Rabab-e-Neyriz’ fruit were stored at 2 ± 0.5 °C (chilling temperature) and 90 ± 5% relative humidity (RH) for 70 days. IW was performed as one warming period by transferring the fruit to a warm room (1 day at 20 °C with 70% RH). The experimental design was factorial based on a complete randomized design. Experimental factors included 4 temporal points of interruption in storage, i.e., 15th, 25th, 35th or 45th days of storage; 2 levels of warming regime for each interruption date, i.e., warming and control; and 2 levels of sampling time, i.e., immediately after treatment or postponed until the end of the storage period. Treated fruit were compared to controls twice, immediately after treatment and at the end of the storage period. Warming on the 15th day of storage led to higher enzymatic antioxidant activity and phenolic content coincided with lower polyphenol oxidase (PPO) activity in the peel and, as a result, lower chilling injury (CI) damage to the treated fruit compared to control. It was concluded that a successful and commercially applicable method for postharvest cold storage of pomegranate could be the only one warming period prior to the incidence of irreversible damage.

In this study, exogenous salicylic acid (SA) was sprayed on two Pistacia species to improve their growth characteristics and physiological status at the seedling stage under salinity conditions. The aim was to determine the efficiency of SA in alleviating salt stress per species. The experiment consisted of three independent variables, i.e. Pistacia species, sodium chloride (NaCl) concentration, and SA concentration. There were two species, namely, Pistacia vera ‘Badami-Zarand’ (‘Badami’) and P. atlantica subsp. ‘Atlantica’ (‘Atlantica’). NaCl concentrations (0, 50, and 100 mM) were added to irrigation water. SA treatments (0, 0.5, and 1.0 mM) were applied as foliar sprays. The plants were sprayed with SA solutions once a week for 7 weeks. Salinity treatments were applied for 12 weeks. Several growth parameters were measured during the experiment, including stem height, stem diameter, leaf count, leaf area, and shoot and root dry weights (DW). Other dependent variables included relative water content (RWC), free proline, chlorophyll content, total soluble sugars, leaf H2O2 and malondialdehyde (MDA) concentrations. Salinity significantly decreased growth parameters. It also decreased RWC (%) and chlorophyll index (SPAD value) but increased total soluble sugar content (mg/g DW), free proline (µg/g FW), H2O2 (mM) and MDA (n mol/g FW) concentrations. Exogenous SA improved the growth and physiological status of plants while reducing the negative effects of salinity. SA increased the concentration of H2O2 but decreased the lipid peroxidation index. The efficiency of SA in improving salinity tolerance in Pistacia species depended on the NaCl concentration and species. Extremely salinized irrigation water (100 mM NaCl) inflicted the greatest damage on the plants. The foliar application of SA at 1.0 mM was most effective in alleviating the adverse effects of salinity. To the best of our knowledge, this is the first time a comparative approach has been applied to two different Pistacia species, considering their physiological response to SA treatments and their acquired salinity tolerance. The ‘Atlantica’ rootstock responded more favorably to SA applications. Compared to ‘Badami’, ‘Atlantica’ showed better growth parameters and more promising physio-biochemical features that proved it more tolerant.

Reduced availability and quality of water for irrigation have decreased olive growth and productivity in recent years. This study was conducted to identify salinity tolerant cultivars and the role of ion toxicity in salinity tolerance of olive cultivars: ‘Amigdalolia’, ‘Dousti’, ‘Tokhm‑e Kabki’ (‘TK’) and ‘Conservolia’. Salinity stress, which was imposed by adding sodium chloride (NaCl) to irrigation water (1.1 [control], 4.0, 8.0, and 12.0 dS · m−1) induced growth inhibition, leaf abscission, chlorophyll degradation, and electrolyte leakage in leaves. By increasing the NaCl concentration in the irrigation water, concentrations of sodium (Na+) and chloride (Cl−) increased in the leaves and roots of the plants. Salinity stress decreased leaf number and leaf area of ‘TK’ and ‘Conservolia’. Moreover, under 8.0 and 12.0 dS · m−1 stress shoot apex development in ‘Conservolia’ was restricted and electrolyte leakage was detected in leaves of ‘TK’ and ‘Conservolia’. Despite having higher Na+ and Cl− concentrations in leaves and roots, growth of ‘Amigdalolia’ and ‘Dousti’ was not affected by salinity stress. ‘Amigdalolia’ could tolerate up to 0.820% of Na+ in its leaves without presenting cell membrane damage. The results indicated that olive salinity tolerance is attributed to compartmentalization of toxic ions rather than controlling salt transport or maintenance of a high K+/Na+ ratio.

Introduction. Research was conducted at the Pistachio Research Institute in Rafsanjan, Iran, to evaluate the effects of ‘Badami’ (Pistacia vera L.), ‘Sarakhs’ (wild P. vera) and ‘Beneh’ (P. mutica F. & M.) seedling rootstocks on the nut quality of ‘Owhadi’, ‘Kalleh-ghuochi’ and ‘Ahmad-aghaie’ pistachio cultivars. Twenty-year-old trees of these nine rootstock/scion combinations were used in a two-year study done in 2003 and 2004. Materials and methods. Growth parameters [trunk cross-sectional area (TCA), tree height, canopy diameter, shoot growth, leaf area and number of suckers], yield parameters (cumulative yield and yield efficiency), and nut quality (blankness, splitting, nuts per ounce and weight of 100 nuts) were measured. Results and discussion. TCA was significantly lower on ‘Sarakhs’ rootstock than on the two other rootstocks and ‘Sarakhs’ was the least vigorous among the tested rootstocks and gave the lowest leaf area of scion cultivars. ‘Sarakhs’ rootstock consistently influenced the formation of the highest number of suckers. ‘Badami’ rootstock allowed us to obtain the greatest cumulative production and yield efficiency, the lowest blankness of pistachio nuts, and the highest percentage of splitting of pistachio nuts. Conclusion. Our study showed that genetic variability among pistachio rootstocks may influence scion vigour, yield, extent of shell splitting, blankness and nut weight. Introduction. Une recherche a été conduite à l'institut de recherches sur le pistachier, à Rafsanjan, Iran, pour évaluer les effets des porte-greffes ‘Badami’ (Pistacia  vera L.), ‘Sarakhs’ (P. vera sauvage) et ‘Beneh’ (P. mutica F. & M.) sur la qualité des noix de trois cultivars de pistachier : ‘Owhadi’, ‘Kalleh-ghuochi’ et ‘Ahmad-aghaie’. La production d’arbres de 20 ans représentant ces neuf combinaisons de greffons / porte-greffes a été étudiée pendant deux années de production en 2003 et 2004. Matériel et méthodes. Des paramètres de croissance (surface de section du tronc, hauteur d'arbre, diamètre de la frondaison, croissance des arbres, surface foliaire et nombre de pousses), de rendement (rendement cumulé en noix et efficacité de rendement), et la qualité de noix (noix vides ou fendues, nombre de noix par once, poids de 100 noix) ont été mesurés. Résultats et discussion. La surface de section du tronc a été significativement inférieure pour les cultivars greffés sur le porte-greffe ‘Sarakhs’ que sur les deux autres porte-greffes et ‘Sarakhs’ a été le moins vigoureux parmi les porte-greffes considérés ; il a induit la plus faible surface foliaire aux cultivars utilisés comme greffon. Le porte-greffe ‘Sarakhs’ a influencé la formation du nombre le plus élevé de pousses. Le porte-greffe ‘Badami’ a permis d’obtenir la plus grande efficacité de rendement et le meilleur rendement cumulé, le moins de pistaches vides, et le plus fort taux de pistaches fendues. Conclusion. Notre étude a montré que la variabilité génétique des porte-greffes de pistachiers peut influencer la vigueur, le rendement, le taux de coquilles fendues, le taux de coquilles vides et la production de noix par le greffon.