Pomology
F. Azarmi-Atajan; M. H. Sayyari Zahan; A. Mirzaei
Abstract
IntroductionPhosphorus (P) is one of the most important nutritional elements of plants and it is necessary for the development of plant roots. Due to the high cost of chemical fertilizers, it is important to use cheap sources such as rock phosphate (RP) to supply P needed by plants. The efficiency of ...
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IntroductionPhosphorus (P) is one of the most important nutritional elements of plants and it is necessary for the development of plant roots. Due to the high cost of chemical fertilizers, it is important to use cheap sources such as rock phosphate (RP) to supply P needed by plants. The efficiency of RP is low and its use alone cannot supply the P required by the plant. One of the ways to increase the efficiency of RP is to use phosphate solubilizing bacteria (PSB). Considering the salinity of soil and irrigation water in many pistachio-growing areas of Iran, the use of salt-resistant PSB can increase their resistance to salt stress in addition to supplying the P required by pistachios. Materials and MethodsIn order to investigate the role of PSB in supplying the required P of pistachio seedlings under saline conditions, a factorial experiment was conducted in the form of a completely randomized design with 3 replications in greenhouse conditions. The factors included PSB at three levels [control (PSB0), Pseudomonas sp. 1 (PSB1) and Pseudomonas sp. 2 (PSB2)], RP at two levels (0 and 30 mg P from rock RP) and irrigation water salinity at three levels (0, 5 and 10 dS/m). The bacteria used in this study were able to produce ACC-deaminase, indole acetic acid and dissolve tricalcium phosphate in vitro. For inoculation, inoculum containing each bacterium with a population of 108 cells/ml was prepared in the nutrient broth medium and each pistachio seed (P. vera L. cv. Badami) was inoculated with 500 µL of bacterial inoculum. The plants were irrigated with non-saline water for four weeks and then with saline water until harvesting based on experimental treatments. During the growth period, the soil moisture of the pots was kept at about 80% of the field capacity by weight method. Finally, shoot and root sampling was performed and various characteristics such as shoot and root dry weight, chlorophyll, carotenoids, proline, soluble sugars, RWC, MSI and phosphorus as well as sodium concentrations were measured. Analysis of variance of traits was performed using SAS software and the means were compared using the LSD method with a probability level of P≤0.05. Results and DiscussionThe results showed that water salinity decreased the dry weight of shoot and root, chlorophyll a, chlorophyll b, carotenoids, relative water content (RWC) and membrane stability index (MSI) of leaf and p concentration of shoot and root of pistachio seedlings. Auxin produced by bacteria can directly increase cell division and growth or indirectly increase ACC-deaminase production. On the other hand, proline, soluble sugars and sodium were accumulated in the leaves of seedlings with increasing water salinity. According to the results, although the use of RP alone did not show significant effect on the studied indicators, its simultaneous use with PSB had the greatest role in improving the growth of pistachio seedlings, especially in saline conditions. The highest amount of dry weight of shoot (1.89 g.plant) and root (1.59 g.plant), chlorophyll b (1.30 mg/g fresh weight), carotenoids (1.35 mg/g fresh weight), soluble sugars (59.1 mg/g fresh weight), proline (36.7 mg.g-1 fresh weight), leaf RWC (91 %), leaf MSI (84%) and the P concentration of shoot (0.39 %) and root (0.35 %) was obtained from the simultaneous application of RP and PSB (especially PSB2) in non-saline conditions. The PSB increase soil P availability by reducing of soil pH by release of protons and organic acids and mineralization by production of acid phosphatases. Bacteria, in addition to increasing soil P availability, improve phosphorus uptake and chlorophyll content in plants by affecting root morphology and its development in soil. On the other hand, inoculation with PSB (both separately and together with rock phosphate) reduced sodium accumulation in the aerial parts and roots of pistachio seedlings. ConclusionUnlike pistachio trees, the tolerance of pistachio seedlings to salt stress is low. According to the results, the salinity symptoms were visible in the pistachio seedling leaves at the water salinity level of 10 dS/m, which caused the drying of the lower leaves and the burning of the edges of the young leaves. On the other hand, although the application of RP alone did not have significant effect on increasing the tolerance of plants to salt stress, the simultaneous use of RP with PSB increased growth, the accumulation of proline and soluble sugars, the concentration of chlorophyll and carotenoids, the amount of RWC and MSI and P concentration of pistachio seedlings, especially in saline conditions. Therefore, the use of PSB can help the growth and establishment of pistachio seedlings under salinity stress conditions and increase the efficiency of RP and supply P needed by the seedlings.
Hassan Farhadi; Mohammad Mehdi Sharifani
Abstract
Introduction: Iran, is the largest producer and exporter of pistachio (Pistacia vera L.), among the major pistachio producing countries in the world including USA, Turkey, Italy and Greece. Due to the altered nature of the pistachio, the high yield of the pistachio is due to the fact that the ...
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Introduction: Iran, is the largest producer and exporter of pistachio (Pistacia vera L.), among the major pistachio producing countries in the world including USA, Turkey, Italy and Greece. Due to the altered nature of the pistachio, the high yield of the pistachio is due to the fact that the environment is quite suitable and fertility of the female flowers is high. As the edible and consumable part of this fruit is its kernel, it is essential for brain formation, pollination and inoculated. Therefore, the aim of this study was to investigate the effects of artificial parent pollination of Integrima species on seed properties obtained by crossing with ‘Fandoghi’ pistachio cultivar and also to compare the effects of Integerrima pollen with domestic pistachio pollen on the quantity and quality of pistachio fruits and seeds. Materials and Methods: The experiment was conducted as factorial based on randomized complete block design with three replications in one of Astan Qods Razavi pistachio gardens in Bardsaskan-Anabed city, 297 km from Mashhad during 2018-2019. Experimental treatments included two pollinator methods (spray and brush) and five flour-pollen combinations. Each replicate had one tree and five branches that were selected from each tree with at least three to four flower buds. Four of them were controlled for pollination and one branch was considered for negative control. The branches were insulated by two-layer bags. The fruits were harvested in late summer and some quantitative and qualitative traits were measured. Results and Discussion: Analysis of variance showed that the effect of flour-pollen blend on fruit formation of ‘Fandoghi’ cultivar in the first stage was significant (p≤0.01), but there was not a significant difference between the simple effect of their pollen and the interaction of their mixture and pollen (p≤0.05). The amount of fruit formation in the second stage showed a significant difference with respect to the simple effect of flour-pollen blend (p≤0.01) but there were no significant differences between the mixture and pollinator for simple and their interaction effects (p≤0.05). All of the simple and interactions effects of variations were significant (p≤0.01) on the final stage of fruits shape of ‘Fandoghi’ cultivar. Fruit loss was significantly (p≤0.01) affected by simple effect of flour-pollen blend, but there was no significant difference (p≤0.05) of simple and interaction effects of their pollen between blend and pollen variations. None of the simple and interaction effects of variations were not significant on wet weight of fruit. No significant difference was observed between the effect of pollen and pollen interactions between the mixture and their pollen, and the effect of simple mixture of flour-pollen show significant (p≤0.01). The effect of pollen and flour-pollen mixture on dehiscent was significant (p≤0.01), but the interaction of pollen in the mixture was not significant. Correlation coefficients of traits under evaluation showed that there was a significant positive and negative correlation between different traits, so that the highest positive and significant correlation (88%) was observed between the second stage and the final stage of fruit formation.
Nasrin Gharaei Masjedi; Mohammad Hossein Shamshiri; Mohammad Reza Dehghani
Abstract
Introduction: Pistachio (Pistacia vera), as one of the most important horticultural products of Iran, has been embraced as one of the main commercial products. Rafsanjan is an important area of pistachio production in the world. High production is primarily dependent on the ability of the trees to produce ...
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Introduction: Pistachio (Pistacia vera), as one of the most important horticultural products of Iran, has been embraced as one of the main commercial products. Rafsanjan is an important area of pistachio production in the world. High production is primarily dependent on the ability of the trees to produce large amounts of photoassimilates during the growing season. Nitrogen is the primary nutrient element needed in the greatest quantities for plant growth and physiology. The greatest impact of nitrogen is in relation to photosynthesis. Therefore, the rate of CO2 assimilation has been closely related to leaf nitrogen status. Nitrogen deficiency leads to the reduction in the activities of enzymes involved in photosynthesis and consequently a decrease in the rate of CO2 assimilation. Regarding the key role of nitrogen in metabolic activities, especially photosynthesis, this research was conducted to investigate the effects of repeated foliar applications of urea on photosynthesis parameters of “Kalleh-ghuchi” pistachio cultivar.
Materials and Methods: This research was conducted to assess the effect of repeated foliar applications of urea on photosynthetic parameters of pistachio trees in different stages of fruit growth, as a factorial experiment based on a randomized complete block design with five replications. In this experiment, urea was applied at the rate of 0.5% at three different stages of fruit growth including initiation of embryo growth, rapid growth of embryo and during flower bud abscission with two weeks interval. Measurement of photosynthesis parameters (including photosynthesis (A), transpiration rate (E) and stomatal conductance (gs) and intercellular CO2 concentration (Ci)) were done by used a portable photosynthesis system, after measuring photosynthesis parameters, chlorophyll fluorescence parameters (Fv/Fm and PII) were recorded by using a Chlorophyll Fluorometer. Leaf nitrogen content was determined by the kjeldahl method. Leaf chlorophyll and carotenoids content were measured according to porra (2002). Photosynthetic nitrogen use efficiency (PNUE) was calculated as the ratio of photosynthesis to foliar nitrogen content. All above parameters was performed in two times, one day after the last spraying and 10 days after the first stage of measurement. The experimental data was analyzed by SAS software and the significant differences among the treatment were tested by Duncan test.
Results: The results showed that photosynthesis and transpiration rate and stomatal conductance were increased in urea treated trees compared to control in both sampling dates, while intercellular CO2 concentration was decreased by urea application. Three times applications of urea caused a 20% increase in photosynthesis rate compared to control trees. Leaf nitrogen content was also increased by repeated urea application in two sampling dates, as three times application of urea resulted in a 65% increase in leaf nitrogen concentration compared to the control , while photosynthetic nitrogen use efficiency decreased by urea application. Fv/Fm and PII were improved by repeated urea applications in two sampling dates. The results also indicated that chlorophyll pigments were increased by urea application. Generally, results showed that the maximum of photosynthesis and related parameters were obtained with three applications of urea at second date of sampling.
Discussion: Any increase in photosynthesis with urea application indicates that more nitrogen maybe allocated to the enzymes of the carbon assimilation. Thus, more CO2 could be used by the plant, therefore increases in CO2 assimilation was accompanied by a decrease in the Ci due to nitrogen application. In the present study, nitrogen application increased stomatal conductance of pistachio trees. Application of nitrogen can influence stomatal opening, and thus transpiration rate. Increased chlorophyll content with applied nitrogen indicates paramount role of nitrogen in determining of chlorophyll synthesis. Increasing photosynthesis rate is always accompany with chlorophyll fluorescence reduction that is in agree with our results. Differences in PNUE are mainly brought about by differences in photosynthetic capacity or foliar nitrogen allocation either within the photosynthetic apparatus or to non-photosynthetic pools (e.g. cell walls, nitrate).
Conclusion: The results of this study showed that urea application can improve photosynthesis capacity by increasing nitrogen content of pistachio leaves. In this experiment, repeated foliar applications of urea in different stages of fruit growth had positive effects on photosynthesis and other dependent parameters which may be effective in reduction of alternate bearing in pistachio trees. On the other hand, the effect of nitrogen application on photosynthesis was continued for more than a month after application, compared to control.
Ali Tajabadipour; Mohammadreza Fattahi; Zabihollah Zamani; Fatemeh Nasibi; Hossein Hokmabadi
Abstract
Introduction: Spring cold injury is one of the main limiting factors to production and distribution of pistachio. Pistachio is one of the most valuable and exported agricultural crops of Iran. Since, spring frosts results to considerabe damage to this plant, hence, it is important to investigate methods ...
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Introduction: Spring cold injury is one of the main limiting factors to production and distribution of pistachio. Pistachio is one of the most valuable and exported agricultural crops of Iran. Since, spring frosts results to considerabe damage to this plant, hence, it is important to investigate methods for reducing freezing damage. For this reason, selection of rootstocks and cultivars are an important objective in breeding programs. Freezing temperatures (below 0ºC) cause the movement of water from the protoplast to the extracellular space, resulting in the growth of extracellular ice crystals and ultimately, cell dehydration. Plants have developed complex processes to survive and recover from unfavorable conditions. To tolerate cold stresses, plants develop multiple mechanisms, including the accumulation of cryoprotective molecules and proteins, alterations in membrane lipid composition, and primary and secondary metabolite composition, as well as changes in global gene and protein expression Frost affects cell membranes, which become less permeable, and even break, giving rise to the leakage of solute from damaged cells. There is often a good correlation between ion leakage and freezing tolerance (22). Sugars may depress the freezing point of the tissue and act as a nutrient and energy reserve, alter phase properties of membranes in the dry state and act as cryoprotectants to preserve protein structure and function. Other compounds acting similarly are lipids, soluble proteins and free proline (44). Proline seems to have diverse roles under osmotic stress conditions, such as stabilization of proteins, membranes and subcellular structures and protecting cellular functions by scavenging reactive oxygen species (23). The aim of the present study was to evaluate different degrees of sensitivity to low temperatures in different genotypes and ‘Ahmad-Aghaii’ cultivar in relation to physiological and biochemical changes in field conditions.
Materials and Methods: In order to determine the effects of rootstock on pistachio cultivar ‘Ahmad-Aghaii’ under freezing stress conditions, an experiment was carried out as factorial based on a randomized completely design (RCD) with four replications. Treatments consisted of two levels: 1- rootstock genotype (four cold sensitive and tolerant rootstocks) and 2- temperatures (-2 and -4 ºC). The sampling was performed in full bloom stage from apical branches of pistachio cultivar ‘Ahmad-Aghaii’ budded on these rootstock genotypes. The branches in pots contain distillted water treated under -2 and -4 °C for 2 h. After treatment, the chilling index was determined. Flower clusters were used for measuring physiological and biochemical parameters. All determinations were carried out in four triplicates and data were subjected to analysis of variance. Analysis of variance was performed using the ANOVA procedure. Statistical analyses were performed according to the SAS software. Significant differences between means were determined by Duncan’s multiple range tests. P values less than 0.05 were considered statistically significant.
Results and Discussion: The results showed that chilling index was significantly lower in the cold-tolerant rootstocks than cold-sensitive rootstocks at -2 and -4 ºC. Also, Results indicated that electrolyte leakage, hydrogen peroxide (H2O2) and malondialdehyde (MDA) were significantly lower in tolerant rootstocks than sensitive ones. The content of soluble carbohydrate, total protein and proline were significantly higher intolerant rootstocks than sensitive ones. The activity of anti-oxidant enzymes ascorbate peroxidase (APX), guaiacol peroxidase (GPX) and catalase (CAT) in tolerant rootstocks was greater than sensitive rootstocks. The reaction of temperature and rootstock indicated that electronic leakage, proline, H2O2,و and MDA significantly increased in -4 ºC. The activity of anti-oxidant enzymes APX, GPX and CAT decreased in -4 ºC as compared to -2 °C especially in cold-sensitive rootstocks. Some researchers believe that the accumulation of proline is as an index to select the drought-resistance varieties (26, 48). Stated that there was no comprehensive information about the relationship between the accumulation of proline and tension resistance. Research on apricot and peach confirmed the results of the present study because this pattern is also seen in their proline level (26 and 41). While the starch concentration decreases during the dormancy, the amount of proline increases which is in accordance with their results (36).
Conclusions: In this study, the damage of the membrane increased with decreasing temperature. The results showed that the rootstocks could increase the resistance to cold by increasing the amount of soluble sugars, protein, proline and the activity of the antioxidant system in the shoots and leaves of the scion. Regarding physiological and biochemical studies, it was determined that ‘Ahmad-Aghaii’ cultivar budded on cold tolerant rootstocks had higher soluble sugars, total protein, proline and CAT, APX and GPX enzymes activity and had less chilling index, ion leakage, H2O2 and MDA, which indicates less damage to the membrane of the cell and its contents compared with the cultivar 'Ahmad-Aghaii' budding to sensitive rootstocks. Consequently, the findings of this study selected TR1 as the most tolerant rootstock compared to other ones.
Mina Nurzadeh Namaghi; Gholamhossein Davarynejad; Hossein Ansari; Seyyed Hossein Nemati; Ahmad Zarea Feyzabady
Abstract
Introduction: Mulching is a useful practice with the potential of conserving moisture, reducing evaporation, modifying soil temperature, and improving aeration as well as releasing nutrients in the soil profile. Mulching involves the use of organic materials (e.g. crop residues, straw, grasses, and farmyard ...
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Introduction: Mulching is a useful practice with the potential of conserving moisture, reducing evaporation, modifying soil temperature, and improving aeration as well as releasing nutrients in the soil profile. Mulching involves the use of organic materials (e.g. crop residues, straw, grasses, and farmyard manure) or inorganic and synthetic materials (e.g. polyethylene sheets, and gravels). Application of mulch can notably as a soil management method influence agricultural crop production despite the limited amount of water available in arid and semi-arid areas.
Materials and Methods: Field studies were conducted in a randomized complete block design with five replications for two years in 2014 and 2015 at Feyzabad city, Iran (34° 40´ N, 58° 25´ E). The aim of the study was to investigate the effects of different mulching treatments on physiological traits of pistachio (Pistaciavera L.) in relation to soil temperature and moisture variations. The treatments were: M1 (whitepolyethylene film mulch covered with two centimeter of soil with width cut), M2 (white polyethylene film mulch covered with two centimeter of soil with circular cut), M3 (green polyethylene film mulch which was as a single layer pulled on water strip so that irrigation water passes under the coverage), M4 (woodchip mulch), M5 (barley residue mulch), and CK (control or no mulching). The measurement (soil moisture and temperature, stomatal conductance and leaf temperature) was carried out periodically on the central trees (4 trees per treatment) every 12, 24 and 36 days after irrigation between 12-15 pm from early-May to late September. The data obtained from the experiment were subjected to an analysis of variance (ANOVA) by using SAS 9.1 software. Difference between means was compared using least significant difference test (LSD) at 5% level (p ≤ 0.05).
Results and Discussion: The results showed that the mean soil moisture percentage in all mulches especially plastic mulches was higher compared to the control over two years of experiment. During the two years of experiment, treatments of M1, M2 and M3 with 35.2, 35 and 38.9 °C and treatments of M4, M5 and CK with 28.8, 29.6 and 32.8 °C indicated the highest and lowest average soil temperature at 20-30 cm soil depth, respectively. Also, similar results were observed at 50-60 cm soil layer. M3 and CK treatments with 47.7 and 41.1 mmol/m-2s-1 had the highest and lowest mean stomatal conductance, respectively. The mean values of leaf temperature during the growing period under M1, M2, M3, M4 and M5 treatments were 2.2, 1.9, 2.4, 1.7 and 1 °C in 2014, and 1.8, 2.2, 2.2, 1.5 and 1.1 °C in 2015 lower than CK (control) treatment, respectively. According to correlation results significant difference was not observed between stomatal conductance and soil moisture, but the relationship of this parameter with soil temperature and relationship between leaf temperature with soil moisture and soil temperature were significant. Thus, this results demonstrate that stomatal conductance and soil temperature weresignificantly affected by soil temperature, so that an increase in soil temperature to 40 °C, canbe improved these traits if other soil and climatic factors werenot limiting. The results also showed that M3 mulch (plastic mulch on soil surface) despite the higher soil water storage due to providing of soil high temperatures, can be leads to moisture stress in heavy cropping year.
Conclusions: The results of thisstudy showed that organic and inorganic mulches improved the soil moisture content throughout the two growing seasons, thus reduced negative effects of water shortage. Mulch treatments indicated smaller fluctuations in soil temperature compared to CK (control) treatment, possibly due to insulating against heat radiation. The results of our study suggested that increase in soil temperature in M3 treatment, despite higher water storage, had limited impacts on improving stomatal conductance and leaf temperature from early July in the second year. Thus, it seems that high soil temperature in this treatment in ON year that trees' water and nutrients requirement is higher than OFF year acts as a limiting factor and restricts absorption of water and nutrients, resulting in the decrease of physiological activity of trees. Generally, it is conclude that white polyethylene films covered with soil especially M2 and organic mulches due to providing optimum soil temperature, preserving soil moisture and lower cost can be better management options to be applied in pistachio orchards especially in arid and semiarid areas, where traditional irrigation methods with high evaporation level are used.
