Journal of Agricultural Science and Technology
Volume:16 Issue: 2, Mar 2014

This study investigated the export status of stone fruits in Iran during 1997 to 2010. Export trends and revealed comparative advantage of indices, namely, Revealed Comparative Advantage (RCA), Revealed Symmetric Comparative Advantage (RSCA), and Relative Export Advantage (RXA) as well as Trade Mapping (TM) were investigated for cherries, plums, peaches, and apricots. Target markets for these products were ranked using numerical taxonomies. The results showed that Iran had export''s comparative advantage for stone fruits only in 2007 and 2010. But, this index had a positive growth for the stone fruits in those years, indicating an increasing trend in the export status of these products. Trade mapping analysis indicates that although the export market for these products has declined during the period studied, Iran has taken a greater share of the market and is among the winner groups. The principal export markets in decreasing order were found to be Germany, The UK, France, Italy, the Netherlands, Russia, Saudi Arabia, Bahrain, Switzerland, the UAE, and Afghanistan.

Continuous and excessive use of organophosphorus compounds has led to the contamination of water and soil ecosystems. The degradation of organophosphorus insecticides, chlorpyrifos, chlorpyrifos- methyl, cyanophos and malathion in mineral salts media were studied. The effect of additional biofertilizers, singly or combined with organic amendments, on chlorpyrifos and cyanophos degrading activity in soil were investigated. Paenibacillus (Bacillus) polymyxa (Prazmowski) and Azospirillum lipoferum (Beijerinck) were found to degrade the organophosphorus insecticides, chlorpyrifos, chlorpyrifos- methyl, cyanophos and malathion in mineral salts media as a carbon and phosphorus source. Paenibacillus (Bacillus) polymyxa (Prazmowski) appeared to be more effective than Azospirillum lipoferum in degrading all the tested organophosphate pesticides in mineral salts media. The half-life values (t1/2) of chlorpyrifos, chlorpyrifos – methyl, cyanophos and malathion were found to be undetectable, undetectable, 2.4, and undetectable days in mineral salts media inoculated by Paenibacillus (Bacillus) polymyxa (Prazmowski),while they reached 1.6, 0.1, 5.2, and 0.8 days by Azospirillum lipoferum (Beijerinck) compared to 4.4, 1.8, 8.8, and 1.4 days in non-inoculated mineral salts media. Chlorpyrifos and cyanophos degraded in soil samples inoculated by Azospirillum lipoferum (Beijerinck) plus peat- moss more rapidly than in the other treatments. Dual inoculation of Azospirillum lipoferum (Beijerinck) and Paenibacillus (Bacillus) polymyxa (Prazmowski) improved the rate of degradation of chlorpyrifos and cyanophos in soil. Azospirillum lipoferum (Beijerinck) appeared to be more effective than Paenibacillus (Bacillus) polymyxa (Prazmowski) in degrading soil-applied chlorpyrifos and cyanophos. These results highlight the potential of these bacteria to be used in the clean- up of contaminated pesticides – waste in the environment.

The toxicity of chlorpyrifos to three Iranian populations of two-spotted spider mite, collected from Isfahan (ISR), Yazd (Yz) and Guilan (GUS2) Provinces were surveyed using the residual contact vial bioassay. The bioassay results showed that resistance ratios of ISR and Yz populations were 176.90 and 9.78 fold compared to the GUS2 population, respectively. Determination of esterase and glutathione-S-transferase activity and their kinetic parameters showed that ISR population had the highest specific activity and specificity constant among the studied populations. Besides, the content of mixed function oxidases in ISR population was the highest. However, synergistic effects of Piperonyl Butoxide, Diethyl Maleate and Triphenyl Phosphate showed that metabolic enzymes did not play an important role in resistance to chlorpyrifos in ISR and Yz populations and enhanced activity of esterase, glutathione-S-transferase and content of mixed function oxidases in these populations were probably due to resistance to some other acaricides. To determine the role of acetylcholinesterase insensitivity in resistance mechanisms, kinetic parameters and inhibitory effect of chlorpyrifos-oxon on this enzyme were investigated. The Km value of acetylcholinesterase was determined as 0.036, 0.04, and 0.050 mM using acetylthiocholine iodide for GUS2, Yz, and ISR populations, respectively. In addition, the insensitivity ratios of chlorpyrifos-oxon on acetylcholinesterase activity were estimated at 23.30 and 2.96 for ISR and Yz populations, respectively. These results confirmed amino acid substitutions in active site of this enzyme and also indicated that resistant population possed qualitatively altered AChE.

Various adjuvants carry out different functions depending on the herbicides types and the target species. Outdoor pot experiments were conducted to evaluate the effects of three post-emergence herbicides, namely, clodinafop-propargyl, haloxyfop-p-methyl, and difenzoquat-methyl-sulfate, as influenced by two adjuvants, on wild oat (Avena ludoviciana Durieu.) control. The study was carried out at the Ferdowsi University of Mashhad, Iran, during 2010. The applied adjuvants were Adigor® and Propel™, registered and sold for use with pinoxaden and tralkoxydim herbicides, respectively, at 0.1 and 0.2% (v/v). These two adjuvants in tank-mixture with the tested herbicides were completely compatible physically and resulted in improvement in controlling wild oats. When Propel™ was added to all three herbicides, herbicidal activity was higher than when Adigor® was added. With increasing adjuvant concentrations, the performance of the tested herbicides increased significantly. In general, the benefit of the two adjuvants appeared greater for clodinafop-propargyl than for the other herbicides. The performance against wild oat of clodinafop-propargyl, haloxyfop-p-methyl, or difenzoquat-methyl-sulfate plus Propel™ at 0.2% was higher by 2.92, 1.42, and 1.67 times, respectively, compared with the use of those herbicides without adjuvants. This result may be related to differences in the physio-chemical characteristics of the tested herbicides. Overall, use of Propel™ with clodinafop-propargyl is recommendable.

In order to assess the effect of salinity constraint on some agro-physiological and biochemical traits in Medicago sativa L., four Alfalfa populations (Tafilalet 1, Tafilalet 2, Demnate and Tata), originated from mountains and oasis of Morocco, were tested. The plants were grown under greenhouse conditions in pots filled with sand and peat under three salt treatments (0, 100 and 200 mM NaCl). Thereafter, plants were harvested 45 days after salt treatment and some agro-physiological and biochemical parameters related to salt tolerance, such as plant biomass, water content, membrane permeability, nutrients contents, nitrate reductase and acid phosphatase activities, were measured. Results showed that increase in NaCl concentration gradually reduced plant biomass, which displayed significant differences among the tested populations. Thus, Tata population appeared to be the most tolerant population to salinity, Tafilalet 1 population was the least tolerant one, while Tafilalet 2 and Demnate displayed moderate salinity tolerance. Variations in plant growth were associated with changes in physiological and biochemical parameters. Indeed, salinity caused a decrease in relative water content, perturbation of membrane permeability, and nutrients concentrations. Results also showed that salinity inhibited nitrate reductase activity in leaves of all tested populations, but acid phosphatase activity was increased in both leaves and roots of stressed plants. Salt tolerance of alfalfa populations was associated with high inorganic ion accumulation and the maintenance of membrane integrity and an adequate level in terms of nitrate reductase and acid phosphatase activities.

A consortium of biofertilizers (Azotobacter chroococcum and Bacillus subtilis) was applied in conventional as well as organic matrix entrapped granular forms as sole nutrient source in two different doses for cultivation of wheat (Triticum aestivum L. cv. PBW-343). A double dose of conventional biofertilizers increased the growth of wheat plants as measured on 30, 60, 90, and 120 Days After Sowing (DAS) in terms of root and shoot length, number of roots and leaves, as well as fresh and dry weight of roots and leaves over the recommended dose (0.6 kg ha-1) of the same biofertilizers. The entrapment of biofertilizers in an organic matrix further increased the efficacy of these biofertilizers over the non-entrapped conventional forms. An increase in the plant growth of wheat by application of higher dose of biofertilizers and entrapped biofertilizers was correlated to the availability of NO3-, NO2- and NH4+ in the plant’s rhizosphere (0-15 cm) and its transport from soil to the plant leaves as well as productivity and yield of wheat in these experimental fields. The increase of 63.47 and 32.17% in wheat yield was recorded in 120-days old plants by the application of organic matrix entrapped biofertilizers in double dose over no fertilizers and un-entrapped biofertilizers in single dose. The results indicate that efficacy of biofertilizers can be enhanced by increasing the dose of biofertilizers and by providing suitable carriers to replace chemical fertilizers load for wheat cultivation with eco-friendly and organic nutrient technologies.

Parkia biglobosa starch was subjected to different heat-moisture treatment (HMT) at different moisture contents (15, 20, 25, and 30%) at 110oC for 16 hours. The content of resistant starch (RS) was the lowest (33.38%) in the untreated native Parkia and increased in the samples with HMT-15 (37.79%), HMT-30 (39.64%), HMT-25 (46.63%), and HMT-20 (50.14%), showing significant increase (P < 0.05) in RS following the HMT. There was a reduction in the swelling power and pasting properties of HMT starches, but the solubility of the HMT starches was higher than that of untreated native starch. Differential scanning calorimetry and the changes in the X-ray diffraction (XRD) patterns confirmed the effect of HMT on Parkia starch. Therefore, replacing native Parkia with heat-moisture treated Parkia starch leads to the development of new products from RS-rich powder with high RS levels and functional properties.

The hawthorn fruits have been used as food and medicine for centuries. In the present study, pulp and seed extract of Crataegus elbursensis Rech. F. fruits belonging to the family Rosaceae and native of northern part of Iran were evaluated for the polyphenol contents, antiradical, antioxidant, and antibacterial activities. The total phenolic, flavonoid, and anthocyanin contents of methanolic pulp extract were found to be more than those of methanolic seed extract. The DPPH radical scavenging, iron (III) reducing capacity, and total antioxidant activity of the extracts depended on concentration. A 200 μg ml-1 of C. elbursensis pulp and seed extract and butylated hydroxytoluene (BHT) exhibited 82.13, 83.47, and 85.44% inhibition, respectively. However, effect of the extracts in the total antioxidant activity and reducing power were not significantly as good as BHT. In addition, the results showed that both pulp and seed extract had inhibitory activity against the four bacteria tested, with the pulp extract showing more activity than the seed extract. Also, phenolic acids were identified by RP-HPLC and chlorogenic acid was the predominant phenolics in the samples. In conclusion, our results showed that C. elbursensis pulp and seed extract had strong antioxidant and antibacterial activities, which were correlated with its high level of polyphenols.

There is some evidence on the effects of organic acids on the functional properties of native starches. However, there is little information on such effects on modified starches. The main objective of this study was to determine the effects of L-ascorbic acid (150 mg kg-1, as the permitted level in bakery products) on functional properties of cross-linked wheat starch. Once the starch was treated with L-ascorbic acid, some spots and cracks appeared on the surface of the starch granules, as observed under a scanning electron microscope. Besides, the water solubility increased while water absorption decreased, but intrinsic viscosity of the samples, as determined by a U-tube viscometer, remained unchanged. Also, gelatinization temperature and enthalpy of gelatinization, measured by differential scanning calorimetery, as well as the hardness and elasticity of the starch gels decreased, while adhesiveness and cohesiveness of the gels remained unaffected. In general, it was concluded that the ascorbic acid had some degradation effect on cross-linked wheat starch molecules that could further affect its functional properties.

The aim of this paper was to assess the effect of catechol (CH), as a peroxidase inhibitor, and 8-hydroxyquinoline citrate (HQC), as a bacterial inhibitor, on keeping the quality of Gerbera Jamesonii cv. Hongyan cut flowers, known to be limited by vascular occlusion. Blockage in the stem xylem vessels of cut gerbera was studied using light and scanning electron microscope. The results showed that some stem xylem vessels of the cut flowers were blocked during the vase period, and the blockage consisted of some amorphous or physiological deposition and rod-shaped bacteria located within the 5cm stem end of the cut flower. In addition, CH (1.0mM) or 8-HQC (0.45mM) decreased the blockage of stems and reduced the bacterial growth in the vase solution, but extended the vase life without statistical significance. The combination of CH (0.5 or 1.0 mM) and 8-HQC (0.45mM) decreased the blockage and inhibited the bacteria more than CH or 8-HQC alone, and extended the vase life significantly (P≤ 0.05).

Red fleshed apples have high levels of anthocyanins in their flesh. Iran enjoys a large variety of these apples due to its location in Central Asia. In the present study, 20 genotypes including eight Iranian red fleshed and 12 commercial Iranian and foreign apples were selected for the study of genetic diversity of red fleshed apples. We used a set of 11 microsatellite markers (SSRs) to determine genetic diversity and the linkage between these SSRs and red fleshed color. Seven SSRs were amplified and revealed adequate performance. On the whole, 56 alleles were detected ranging from 3 to 11, with an average of 8 alleles per locus. Cluster analysis was performed by the UPGMA algorithm and Dice similarity coefficient through NTSYS-pc ver. 2.02 software. The obtained dendrogram classified the studied genotypes into seven categories. Heterozygosity and Shannon Index were estimated using POPGEN 1.32 software. The genetic diversity for the two populations (Iranian and foreign) were calculated using Gene Alex ver. 6.3 software. These findings can be helpful for conservation and selection of these genetic resources and future breeding programs.

Pruning of the plant canopy and paclobutrazol application to the root zone are agronomic practices that improve harvest yield in mango (Mangifera indica L.) orchards. To assess the effect of pruning and paclobutrazol treatment on the vegetative and reproductive development of ‘Ataulfo’ mango, three pruning dates (20 April, 20 May, and 20 June) and three concentrations of paclobutrazol (PBZ) (7.5, 11.25, and 15 mL of active ingredient) were used. While control trees presented only one vegetative growth during the productive cycle, trees that were pruned and treated with PBZ had up to three vegetative growth cycles before flowering, regardless of whether pruning occurred in April, May, or June. The number of vegetative shoots and inflorescences (m-2) were equal when trees were pruned and PBZ was applied. When pruning was performed in April or May, the time of harvest occurred 28 days earlier compared to the control. Pruning in April numerically resulted in the greatest production efficiency (7-11 kg m-2). For all the three pruning dates, fruit production of trees treated with PBZ and pruning was from 38 to 98 kg; these values were always less than those obtained for the control trees. The greatest incidence of seedless fruits (57-80%) occurred when pruning was performed in June.

Closed-end furrows are commonly used to irrigate crop in northern part of China. The irrigation performance of furrow in this area is often low. The objectives of this paper are to verify reliability of infiltration parameters and Manning roughness estimated with SIPAR_ID software and present an optimized method for design of closed-end furrow system. The study consisted of field experiments and numerical simulation. Field experiments were conducted in two villages of Yangling district in October 2007. Infiltration parameters and Manning roughness values were estimated with SIPAR_ID software. The estimated values were put into the WinSRFR software, and then the advance trajectory, flow depths in the upstream, and irrigation performance were simulated on each test furrow. The results showed that the simulated values with the WinSRFR software were in excellent agreement with the measured data. Therefore, the infiltration parameters and Manning roughness estimated with SIPAR_ID software were reliable. Later, an optimized model for design of closed-end furrow irrigation system was proposed, based on field data and using the project of Uniform design and the WinSRFR software. Its solution required the use of optimized methodology with genetic algorithm (GA), and the inflow discharge and cutoff time were the independent variables. The results showed that adequate and efficient irrigations can be obtained using closed-end furrows through a proper selection of inflow discharge and cutoff time.

An efficient transformation system for the medicinal plant Portulaca oleracea was established using agropine-type Agrobacterium rhizogenes ATCC15834. Hairy roots were obtained directly from cotyledon leaves explants seven days after inoculation with the bacteria. The highest transformation efficiency was obtained from cotyledon leaves explants, and amounted to 53.3% within two weeks. Roots grew rapidly on solid growth regulator free ½ Murashige and Skoog medium and demonstrated characteristics of transformed roots such as fast growth and high lateral branching. Successful and stable transfer of rolB gene was illustrated by PCR using specific primers of the gene. The hairy roots showed an ability to synthesize natural and medicinal product, dopamine. Elicitation of dopamine production in P. oleracea hairy roots was tested using different concentrations of methyl jasmonate (0, 100, 150, 200 μM) and salicylic acid (0, 125, 250, 500 μM), added to the hairy root cultures during the late growth phase. The results showed that the various concentrations of the methyl jasmonate significantly increased the dopamine content, but, at concentration of 100 μM, its impact was the most pronounced. Salicylic acid had no significant influence on dopamine production in hairy roots of P. oleracea.

Rye (Secale cereale) chromosome 1RS harbors multiple genes including Lr26, Sr31, Yr9 and Pm8 conferring disease resistance and tolerance to abiotic stresses. The introgression of the rye 1R chromosome short arm has enormously contributed to increase of genetic diversity in wheat. Utilization of such translocations in breeding programs demands identification of wheat germplasm possessing the wheat-alien chromosome translocation. This study was designed to screen a set of 102 Pakistani wheat cultivars and candidate lines to identify the rye T1BL.1RS translocation, using cytological, biochemical, and molecular techniques. Results revealed that 12 out of the 40 wheat cultivars were found to have this alien introgression. In the National Uniform Wheat Yield Trials (NUWYT) group, 10 of 23 entries of the rainfed category were identified as carrying 1BL.1RS translocation, while 4 out of 39 genotypes were present in the irrigated category of both NUWYT crop seasons. The valuable information generated can be useful in the crop improvement programs for the production of germplasm possessing T1BL.1RS translocation, in order to enhance the genetic variability in local wheat cultivars and, also, avoid the preponderance of T1BL.1RS candidates.

In the present study, random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers were used to estimate genetic diversity and relationships among 35 cluster bean [Cyamopsis tetragonoloba (L.) Taub] genotypes. For RAPD analysis, 20 random primers were used which amplified 164 bands, 147 of which were polymorphic with an average polymorphism of 90.3%. The amplified products varied in size from 250 to 2,050 bp. For ISSR analysis, 10 primers were used which produced 105 bands, 102 of which were polymorphic (97%). The size of amplified bands ranged from 450 to 3,500 bp. The efficiency of primers in generating sufficient information for genetic diversity analysis was computed using discriminatory power (Dj), which ranged from 0.40 to 0.98 for RAPDs and 0.44 to 0.99 for ISSRs. Jaccard similarity coefficients were used to estimate the genotypic association with each other, which varied from 0.38 to 0.91 for RAPDs and from 0.20 to 0.88 for ISSRs. Cluster analysis indicated that all 35 genotypes could be distinguished by both RAPD and ISSR markers. Both of the methods (RAPD and ISSR) showed significant correlation (r= 0.69), implying their equal importance in cluster bean diversity analysis.

Zinc has previously been reported to alleviate salinity stress in plants. In this study, we monitored various biomass and chlorophyll fluorescence parameters to determine the optimum zinc sulfate concentration that can be used as foliar spray to alleviate salinity stress in Glycine soja. The plants subjected to a series of salinity levels (NaCl concentration of 0, 100, 200, and 300 mmol L-1), applied via the nutrient solution, were sprayed with different concentrations of zinc sulfate (0, 5, 10, 15, 20, 25 µmol L-1). The results showed that the biomass and chlorophyll fluorescence parameters of seedlings were significantly affected by salt stress (P < 0.05). However, zinc sulfate sprays helped the plants to cope with the stress condition. The zinc sulfate concentrations that helped G. soja to cope with the salinity stress of 100, 200, and 300 mmol L-1 were 15 to 20, 15 to 20, and 10 to 20 µmol L-1, respectively. Lower zinc concentration was ineffective in alleviating stress and higher zinc concentration inhibited plant growth because of toxicological damage to plants. The zinc sulfate spray of 15 µmol L-1 was found to be the most appropriate at all salinity stress levels. The growth measurements such as true leaves part and dry weight of total seedlings were in agreement with the chlorophyll fluorescence parameters, indicating a visible enhancement of leaf photosynthetic activity at 10-20 µmol L-1 zinc concentrations.

Four tylenchid species, namely, Aglenchus agricola, Malenchus exiguus, Psilenchus curcumerus, and P. terextremus are reported from Iran. The Iranian population of A. agricola is characterized by 542-659 µm long body, 10-12 µm long stylet, excretory pore at 70-87 µm distance from anterior end, prominent lateral fields, with four lines, tail of 170-198 long, and rare males with 15-20 µm long spicules. Iranian population of M. exiguus is characterized by 362-412 µm long body, 8-10 µm long stylet, lateral fields with two crenated lines, originating at mid-region of procorpus and ending at 1/3 of the tail length, PUS of 6-9 µm, tail 65-89 µm long and common males with 13-19 µm long spicules. The recovered population of P. curcumerus is characterized by having a smooth head region, 12-15 µm long stylet, presence of post-rectal sac and filiform tail with clavate terminus and the Iranian population of P. terextremus is characterized by lateral fields with crenate margins, appearing as a simple band, with two or three weakly developed bands in cross section and lateral view, respectively, median bulb anterior to the middle of the pharynx and filiform tail with rounded tip. The morphological and morphometric characters of the recovered populations and their differences and similarities with those given in the original descriptions are discussed.