Journal of Agricultural Science and Technology
Volume:22 Issue: 6, Nov 2020

Pistachios play a vital role in Iran’s agricultural export. Recently, however, Iran has lost considerable amount of its market share in international trade. This study aimed to address the price and non-price factors affecting the pistachio markets of Iran by estimating a structural system of equations. The domestic supply and demand for pistachios in Iran along with its export demand and supply to European Union, East Asia, and West Asia markets were estimated simultaneously, during 1988 to 2015. The results indicate that Research and Development (R&D) has had a positive effect on the pistachio supply and exports. Hence, it is proposed that the allocation of R&D funding in Iran be reconsidered. However, advertising has an insignificant effect on the Iranian’s export supply in international market. Hence, reviewing the type of advertisement is a vital issue for future research. European countries are less sensitive to the Iranian’s export price of pistachios, while they pay more attention to the quality and taste of the Iranian’s pistachio.

This study adopted a survey approach to address and determine the effects of educational system components on strengthening the teamwork behavior of students in the agricultural higher education system of Iran. The statistical population consisted of all agricultural students in five universities of Iran. A sample of 291 students was selected using random stratified sampling method with proportional allocation. A structured questionnaire was used to collect data. The data were analyzed by structural simulation technique using Smart PLS software. The results showed that there was a positive and significant relationship between teamwork behavior of students and the components of the higher education system, which included the teacher, student, curriculum, and the learning environment. The results also showed that the curriculum component had the most impact compared to other components. Also, the presented Applied Structural Equation Model is a strong theoretical model for predicting the teamwork behavior of the students.

Four nonlinear models including Logistic, Gompertz-Laird, Richards, and von Bertalanffy were compared to achieve the best prediction of growth parameters describing the growth curve in a crossbred chicken population. Growth data (weekly body weights of chicken from birth to 84 days of age) were collected on 303 birds (174 females and 129 males) of F2 cross of the Arian line broiler chicken (Line B) and Urmia native chicken. Some statistical criteria such as Akaike Information Criterion (AIC), Corrected Akaike Information Criterion for small sample sizes (AICc), and Bayesian Information Criterion (BIC) were used to find the best model. The results showed that the estimated values of the initial weight (W0) and final Weight (Wf) in male were significantly (P< 0.01) higher than the female birds in all models. The average estimated initial weight calculated by Gompertz-Laird (0.038 kg) was closer to the average observed initial weight (0.044 kg). Regardless of sex of the birds, the calculated age (ti) and Weight (Wi) at the inflection point were relatively the same in Gompertz-Laird, Richards and von Bertalanffy models, indicating that the growth patterns described by these models are similar. Meanwhile, the different ti and Wi values between the sexes in the four models revealed the different growth pattern in males and females. The goodness of fit indices (R2 and adjusted R2) were higher than 0.97 in all models, indicating that these models could appropriately be fitted on the growth data. However, based on the AIC, AICc, and BIC criteria, Gompertz-Laird model showed better performance, therefore, it was chosen as the best model to analyze the growth pattern in crossbred of .

Having a short postharvest life, cucumber undergoes rapid loss of quality. In this research, the effects of temperature, oxygen, and postharvest storage time on the respiration rate of Royal cucumbers were investigated. To design a Modified Atmosphere Packaging (MAP) for cucumber in order to extend its shelf-life, a mathematical model using Michaelis–Menten’s equation, with the model constants described by means of an Arrhenius-type relationship, was applied to predict respiration rate at various temperatures (4, 10, and 20ºC) and O2 concentrations. Results revealed that all three factors affected respiration rate of the cucumbers, but the influence of temperature was most pronounced. The model was validated in a commercial passive and active MAP. The model could well predict the O2 change in the package but the modeling of CO2 change, mainly at 20ºC, was not satisfactory, which might be due to occurrence of anaerobic condition. The mathematical model was verified as long as the O2 concentration did not reach anaerobic levels at 20°C. Applying the corresponding respiration, the model will also be applicable for other variety of cucumbers with similar metabolic and respiratory behavior to design the optimal MAP conditions.

Recent trends in food consumption and lifestyle show an increased demand for foods that are not only tasty and nutritious, but also provide additional benefits related to health, i.e. functional foods. One example of functional food is probiotic fermented milk produced with lactic acid bacteria. This has been shown to be beneficial to human gut health. The present study aimed to study the viability of Lactobacillus Casei subsp. casei R-68 (LCR-68) and Lactobacillus Casei strain Shirota (LCS) during fermentation and cold storage, as well as the quality of fermented milk produced from both strains. The research was conducted using a Completely Random Design. The data obtained was analyzed using ANOVA and DNMRT. The t-test was used to compare the growth and viability of LCR-68 and LCS. Fermentation time significantly affected the pH value, total lactic acid, total LAB and protein content, but did not significantly affect the fat and ash content of the fermented milk product. The best probiotic fermented milk in terms of viability and quality was produced via fermentation for 15 hours using strain LCR-68 as a starter. LCR-68 and LCS cultured in skimmed milk showed slightly different growth patterns. However, both strains showed similar viability. The total LAB after cold storage for a month was 6.64 and 6.68 log CFU mL-1 in the LCR-68 and LCS fermented milk, respectively. According to the results, LCR-68 can be used as a starter for making probiotic fermented milk.

The different aspects of using dietary supplements such as prebiotics in aquaculture and their effects on innate immune response, and especially their vertical transmission, are of a grave importance. To address such issues in both horizontal and vertical transmission of boosting immune system, the present study was designed to investigate the effect of different levels of dietary Agrimos® on the innate immune-related gene expression [Lysozyme (Lyz) and Tumor Necrosis Factor alpha (TNFα)], DNA methylation, and three Histone MethylTransferase [HMTs (H3K4, H3K9, H3K27)] activities as well as growth performance in zebrafish (Danio rerio). Three hundred and sixty healthy 24-days-old zebrafish were randomly distributed in twelve aquaria assigned to four groups. Zebrafish were fed with either control diet or a diet supplemented by different levels (0.2, 0.4, and 0.8%) of Agrimos® for 90 days. The offspring of each treatment was assessed to find the potential of vertical transmission of immunity by using this dietary prebiotic. At the end of the experiment, gene expression studies revealed significant up-regulation (P˂ 0.05) of TNFα and Lyz genes in 0.2 and 0.4% Agrimos® fed fish compared with the control group. Although our findings showed that supplemented diet reduced DNA methylation (P˂ 0.05) in Agrimos® treatments compared with the control, there was no significant change in all three HMTs’ activities among experimental groups (P> 0.05). The result shows the successful transmission of Lyz gene expression as an innate immune response to the offspring of the treated adults and supports a direct role of DNA demethylation in the regulation of these candidate gene expressions, suggesting possible role of diet on regulating the epigenetic processes.

Cereal leaf miner, Syringopais temperatella Led. (Lep., Gelechiidae), is an important wheat pest in many regions of the world, including Iran. Fixed precision sequential sampling plan, a cost-efficient method for estimating pest population density, has been used for developing a successful IPM program. In this study, the fixed precision sequential sampling plan of S. temperatella larvae was developed on wheat, cultivar Verinac®, during 2017-2019 growing seasons in Iran. For this purpose, first, spatial distribution of the larvae on wheat leaves was determined using Taylorchr('39')s power law and Iwaochr('39')s patchiness regression. The spatial distribution of the larvae was aggregative on the wheat leaves. Taylor’s power law provided a better fit for the data than Iwao’s patchiness regression. Therefore, Greenchr('39')s model was used for developing the fixed precision sequential sampling plan. The optimum sample sizes of the larvae ranged from 5- 68 plants and 12- 189 plants according to the average of larval density at precision levels D= 0.25 and D= 0.1, respectively. Estimated stop lines showed that the sampling must be continued until the cumulative number of the pest larvae reaches 3.45 (D= 0.25) and 83.76 (D= 0.1) per plant. Accuracy of the sampling plan was validated by RVSP software.

The nutritional indices are an important tool in evaluating herbivore responses to variation in host nutritive properties. The current study was conducted to unveil the effects of ten canola cultivars (Brassica napus L.) (chr('39')Operachr('39'), chr('39')Licordchr('39'), chr('39')Okapichr('39'), chr('39')Talayechr('39'), chr('39')Zarfamchr('39'), chr('39')Modenachr('39'), chr('39')SLM046chr('39'), chr('39')Sarigolchr('39'), chr('39')RGS003chr('39') and chr('39')Hayula420chr('39')) on consumption and utilization indices of the Spodoptera exigua (Hübner) larvae. The results revealed significant differences in nutritional indices of different larval instars of S. exigua fed on the mentioned canola cultivars. The highest value of Digestion Ability of food (AD) for the third and fourth instars was observed on Licord (86.57% and 83.08%, respectively), and for the fifth instars was on Opera (68.79%). The Relative Growth Rate (RGR) and Relative Consumption Rate (RCR) in the fifth instar larvae were significantly greater on Opera, Okapi and Talaye, whereas the lowest values of Conversion Efficiencies (ECI and ECD) were recorded on these cultivars. The highest ECI was observed in the larvae that consumed RGS003 (24.27%), Hayula420 (20.36%), and Sarigol (19.17%). Furthermore, the larvae reared on Okapi exhibited the highest RGR, which confirms high susceptibility of this cultivar. Based on the obtained results, Okapi, Talaye and Opera were the cultivars susceptible to S. exigua.

Improving postharvest and cold storage related indices is one of the main purposes of melon breeding programs. With regards to the growing global market, it is important to introduce new melon types with prolonged storability. In this experiment, six melon inbred lines were used to establish a full diallel F1 population. Harvested fruit was stored and the main postharvest indices were monitored during the storage period. The results showed that some indices were controlled by additive gene effects such as mesocarp firmness and Soluble Solids (SS). Mesocarp firmness analysis proposed that this index was controlled by additive and non-additive gene effects. General Combining Ability (GCA) analysis showed that “Khatouni” inbred line could be considered as a promising parent in breeding programs to produce melon hybrids with more appealing firmness, fewer cold storage losses, and a longer postharvest life.

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.

Digitoxin is a glycoside isolated from leaves of various species of Digitalis genus that are commonly called foxgloves. Digitoxin is used for chronic cardiac insufficiency, tachyarrhythmia form of atrial fibrillation, paroxysmal ciliary arrhythmia, and paroxysmal supraventricular tachycardia. 1-Deoxy-d-Xylulose 5-phosphate Reductoisomerase (DXR) is an important rate-limiting enzyme in 2-C-Methyl-d-Erythritol 4-Phosphate (MEP) pathway, and expression level of DXR plays a critical role in control of plant isoprenoid biosynthesis pathway. The effects of different elicitors including putrescine, spermine, and spermidine at concentrations of 50 and 100 mg L-1 and also Methyl Jasmonate (MJ) at 50, 100, and 200 μM concentrations were explored on transcript levels of DXR gene in cell suspension culture of foxglove (Digitalis purpurea). DXR transcription levels were assessed by the semi-quantitative RT-PCR. Results showed that elicitors had significant effects on the expression level of DXR and contents of cardenolide and digitoxin. The highest digitoxin (61.3 μg g-1 DW) and cardenolide (1.48% mg-1 DW) content was observed in 100 mg L-1 spermidine treatment. In all treatments, the expression of DXR gene was increased compared with the control sample. The highest transcription levels of DXR gene was observed in 50 μM MJ and 100 mg L-1 putrescine elicitors, which was nine folds higher than the control condition, and the lowest levels were observed for putrescine treatments at concentrations of 50 and 100 mg L-1, respectively.

Froriepia subpinnata is an endemic endangered medicinal plant growing indigenous to Caspian coast forest in the north of Iran. This research was done to obtain primary information on morphological and phytochemical variation for the next step of domesticating and breeding of this plant. Twenty-three morphological traits measured indicated high variation among 52 accessions. There was a significant positive correlation between leaf dimension, plant height, and attributes related to biomass data. The range of phytochemical attributes analyzed was for total phenols (355.6-941.3 mg GAE 100 g-1 FW), total flavonoids (204.33-540.74 mg CAT 100 g-1 FW), total carotenoids (1.52 to 3.15 μg 100g-1 FW) and antioxidant capacity (31.36-81.82 DPPH%.). The HPLC analysis results showed that chlorogenic acid was the dominant phenolic compound generally found in this plant. Total carotenoids had no significant correlation with other biochemical traits, while the rest exhibited a linear relationship with each other. UPGMA cluster based on combined data of morphological and biochemical traits showed 3 distinct groups with high inter and intra-regional variations. Also, these information were combined with molecular data to separate environment and genetic effects. The high level of variation of phytochemical and morphological traits among and within populations could be a useful tool for future breeding and selection programs.

We evaluated the effects of Arbuscular Mycorrhizal Fungi (AMF) on percentage of Essential Oil (EO) content, EO yield, EO composition, and anatomical characteristics of lemongrass at four levels of water availability [100, 75, 50, and 25% Field Capacity (FC)]. EO composition was determined by GC-MS analysis, and scanning electron microscopy was used to investigate the anatomical parameters (stomatal density and size as well as glandular trichomes). EO content and yield significantly increased under moderate water stress (50% FC) and AMF inoculation. The highest EO content (1.09%) and yield (0.26 g plant-1) occurred in 50% FC combined with AMF inoculation treatment. In contrast, the lowest EO content (0.68%) and yield (g plant-1) were observed at 25% FC and no AMF inoculation. The main EO components were geranial, neral, β-pinene and nerol. Water stress increased the content of geranial, β-pinene, whereas it decreased the neral and nerol content. In general, AMF inoculation enhanced the geranial, neral, and β-pinene, but nerol was slightly decreased in total. The highest geranial (48.02%) and β-pinene (7.72%) was observed in AMF inoculated plants at 50% FC. However, the maximum content of neral (35.02%) was found in inoculated plants at 100% FC. Water stress changed the stomatal density and size as well as the number of glandular trichomes. The highest stomatal density was observed in 50% FC (148.1 stomata number mm-2). Water stress decreased the stomatal size, with the lowest stomatal length (24.1 µm) and width (14.1 µm) observed at 25% FC. In addition, the number of glandular trichomes at 50% FC (24.6 trichome number mm-2) was greater than the other treatments. This study suggests inoculating lemongrass plants with AMF and maintaining a moderate water stress to obtain the optimum EO.

Genetic manipulation to get desirable characters in cash crops like cotton remains the prime objective of crop biotechnology. To produce transgenic plants resistant against bollworms, newly emerged embryos of MNH-786 cotton variety were transformed with Agrobacterium tumefaciens strain LBA4404 harboring the plasmid pKHG4 vector containing Cry1Ac+Cry2A genes under the control of CaMV35S promoter. The integration and expression of these genes were evaluated by PCR, Florescent In-Situ Hybridization (FISH), and ELISA, respectively. Out of 700 putative transgenic cotton plants, 10 plants (1.03% transformation efficiency) showed the presence of genes Cry1Ac+Cry2A through PCR analysis. In vitro, insect feeding bioassay was done for estimation of mortality percentage of Helicoverpa armigera. Insect mortality rate and morphological characteristics of Bt cotton were analyzed by phenotypic correlation, path coefficient regression and covariance to evaluate the advantage of transgenic technology in numerical terms. Statistical analysis indicated significant positive correlation between insect mortality and cotton seed yield. Helicoverpa armigera mortality data produced a directly proportional relation with cotton seed yield. The results of this study support the improvement of cotton defense mechanism against insects and natural competitors through genetic modification.

Exendin-4 is a human Glucagon-Like Peptide-1 (GLP-1) analogue, resistant to DiPeptidyl Peptidase (DPP), which activates the GLP-1 receptor, increases insulin secretion, and improves glycemic control. In this study, Exendin-4 (EX4) was fused to Cholera Toxin B subunit (CTB) and transiently expressed in tobacco leaves. The sequence of the Ex4 fused to CTB subunit gene, with BamHI and SacI restriction enzymes sites at the beginning of CTB and at the end of EX4 gene. After codon optimization, the sequence was synthesized and cloned in pUC57 plasmid. The recombinant vectors were transformed into Escherichia coli strain DH5α. The pUC57-CTB-EX4 construct was digested with BamHI and SacI restriction enzymes, cloned into pBI121 expression binary vector, and transferred into tobacco leaves through agroinfiltration. Transcription of the Ex4 fused to cholera toxin B subunit gene in leaves was confirmed by RT-PCR analysis. After agroinfiltration, the protein was extracted from treated leaves, and ELISA test was performed using anti-CTB antibody. The production of recombinant protein was approved by ELISA test in transformed leaves.

This study was conducted to evaluate the control efficacy of Pseudomonas chlororaphis, Erwinia herbicola, Bacillus amyloliquefaciens, and Bacillus subtilis, as well as solutions of zinc sulfate, sodium malonate, and oxalic acid against potato white mold caused by Sclerotinia sclerotiorum under field conditions during growing seasons of 2017 and 2018 in Bahar and Lalehjin, Hamedan, Iran. The results showed that strains of Bacillus subtilis as well as zinc sulfate had the highest inhibitory effect against carpogenic germination of sclerotia. The myceliogenic germination of sclerotia was inhibited by solutions of zinc sulfate and sodium malonate with statistically similar results followed by oxalic acid. In addition, activities of resistance-related enzymes including β-N-acetyl hexosaminidase, endochitinase, chitin 1,4-β-chitobiosidase, β-1,3-glucanase, phenylalanine ammonia lyase, polyphenoloxidase, and peroxidase markedly increased in potato leaves due to application of bacteria on plants. The results showed that all treatments were able to reduce significantly (P< 0.05) the number of infected and dead plants in both years. The mixtures of five bacterial biocontrol agents and solution of zinc sulfate were found to be the most effective treatments to control white mold.

Stem rust, caused by Puccinia graminis f. sp. tritici (Pgt), is one of the most important diseases of wheat with devastating epidemics in Iran and the world. In this study, we evaluated some Iranian wheat landraces in a greenhouse at the seedling stage against a new pathotype related to Ug99 of Pgt, which was collected from Iran and designated as TTSSK. Marker analysis was done on resistant landraces. Molecular markers for detecting some Sr genes were used. The results showed that Sr22, Sr35 and SrWeb provided resistance against TTSSK in the resistant landraces. In addition, some of the susceptible landraces that were resistant at adult stage were used for Sr2 analysis. The results showed that some of these landraces were carrying other adult plant resistance gene/genes except Sr2. To evaluate the defence gene expression in compatible and incompatible interactions, cv. Morocco (susceptible) and KC-440 landrace (resistant) were used. Sampling was done at 0, 12, 18, 24, and 72 hours post inoculation (hpi) with stem rust isolate and water as mock treatment. β-1,3 glucanase gene expressions were studied using qGLU-S and qGLU-AS primers. Also, 18srRNA, β-tubulin and EF1-α genes were used as internal control. The results showed that in incompatible interactions, the defence gene expression was increased at 24 hpi, but in compatible interactions, expression level reached the peak at 12 hpi and it significantly decreased at 18 hpi. The results revealed that the expression of defence genes such as β-1,3 glucanase was earlier in compatible interactions than in incompatible interactions, but the quantity of expressed gene was less than in incompatible interactions.

Production of virus-free stocks is crucial for efficient management of plant viruses in cultivation of pome fruits. Regarding the importance of producing the pre-basic stocks of valuable fruit trees, pear cultivar ʽNatanzʼ, an important local pear cultivar in Iran, was selected for virus eradication. In the present study, tissue culture combined with in vitro thermotherapy and thermo-chemotherapy techniques were used for elimination of Apple Stem Pitting Virus (ASPV) and Apple Mosaic Virus (ApMV). In thermotherapy approach, in vitro shoots were initially incubated for 55, 60, 65, and 70 days in alternating temperatures (32/38°C), then, meristems were cultivated on meristem medium. In thermo-chemotherapy approach, in vitro shoots were incubated for 50 days at 32/38°C, and then meristems were cultivated on a medium containing ribavirin. Virus detection by RT-PCR using specific primers was carried out after rooting and adaptation of the regenerated shoots. The percentage of survived shoots and meristem establishment were depended on thermo-duration. After 55 days, 83.33% of shoots survived, while it decreased to 33.33% after 70 days. Both ASPV and ApMV were eliminated after 60 days of thermotherapy. Ribavirin at 10 and 20 mg L-1 reduced the percentage of meristem establishment to 50 and 37%, respectively, compared to the control (88.88%). Thermo-chemothery was also effective for ASPV and ApMV eradication from pear shoots.

Improving yield and Irrigation Water Use Efficiency (IWUE) is important for pistachio cultivation in Iran. Subsurface Drip Irrigation (SDI) is a novel irrigation system that is used by pistachio farmers. Oxygen deficiency could occur in the soil under crops irrigated by SDI, especially in heavy clay soils, due to creation of sustained wetting fronts around emitters. The focus of this work was to evaluate aerated water irrigation (oxygation) under SDI to overcome hypoxia in saline loam silt soil environments on 15 years old pistachio trees in desert climate. Two treatments including F3 (irrigation frequency once every 3 days without air injection) and F3-oxygation (irrigation frequency once every 3 days by air injection) were investigated in two years. The injection of 18% by volume air into irrigation water by SDI resulted in a beneficial effect on yield and IWUE in the second year of experiment; with yield values of 4.9 ton ha-1 for F3-oxygation against 4.4 ton ha-1 for F3; and IWUE values of 4.2 kg ha-1 mm-1 for F3-oxygation against 3.7 kg ha-1 mm-1 for F3. Decreases in yield and IWUE in the F3-oxygation in comparison with F3 were 33.3 and 28.2% in the first year, respectively; but yield and IWUE due to F3-oxygation were 11.1 and 13.5% greater in the second year compared to F3, respectively. At the end of the irrigation season, the nitrogen content of the nuts removal in F3, and F3-oxygation were 1.9 and 2.1% in the first year and 1.4 and 1.6% in the second year, respectively. The leaf K+ and nut Fe2+ concentrations in F3-oxygation were about 24 and 44% more than F3, respectively. Leaf area was larger in aeration treatment compared with the control. Overall, these results indicate positive effects of oxygated SDI system on pistachio trees and merit further investigation for improving yield and IWUE.