علی اکبر مویدی

The new durum wheat cultivar, Sana (line DM-93-8) was initially introduced as a breeding line through 43rd International Durum Screening Nursery (IDSN) received from the International Maize and Wheat Improvement Center (CYMMIT) and was evaluated in Seed and Plant Improvement Institute (SPII) in Karaj. Sana was selected for further evaluations based on its high grain yield (7750 kgha-1) at the subsequent years. This line had average grain yield of 9675 kgha-1 in the regional preliminary yield trial in 2012-2013 cropping season. Line DM-93-8 had average grain yield of 6827 kgha-1 in the advanced yield trial, with no considerable difference with Dena check cultivar having grain yield of 6973 kgha-1 in 2013-2014, therefore this line was selected for the further evaluations. The regional elite yield trials were conducted in four stations of Isfahan, Karaj, Kermanshah and Neishabour in 2014-15 and 2015-16.  This line with 9025 kgha-1 had 16% higher grain yield than Dena check cultivar, with grain yield of 7779 kgha-1, and therefore was selected as superior line based on its grain yield and yield stability. Sana also has high quality of semolina, high protein content (12.2%) and high percentage of wet gluten (27%). The results of on-farm trials showed that this cultivar exhibited a 6% higher grain yield than newly released variety, Hana, as a local check in Kermanshah. Therefore, based on its high grain yield, yield stability, quality of semolina and its good level of resistance to yellow and leaf rusts, line DM-93-8 was released as a new durum wheat cultivar with the name of Sana for moderate agro-climate zone of Iran.

This research was conducted in order to study Genotype × environment interaction effect and identify adaptable durum wheat genotypes with high yield stability in temperate agro-climate zone of Iran.  

Nineteen elite durum genotypes along with a commercial bread wheat check, Mehrgan, were tested in 4 locations, i.e. Karaj, Kermanshah, Neishabour and khorramabad in temperate agro-climate zone of Iran in two years, 2017-18 and 2018-19. The experiments were conducted in a RCBD design with three replications. For grain yield, combined analyses of variance were performed. In order to precise evaluation of genotype by environment interactions and genotypes stability, stability analysis using AMMI method was undertaken.  

Based on two main components of AMMI analysis, genotypes 5, 11, 13, 15 and 20 had good stability and based on ASV index genotypes 5, 7,16 and 19 were more stable than check. Finally, genotypes 5, 16 and 19 with average grain yield of 7.497, 7.326 and 7.551 kgha-1, respectively and high yield stability were selected as superior durum wheat genotypes. These genotypes also were desirable based on the days to earing and maturity, plant height and thousands kernel weight.  

Based on results, genotypes 5, 16 and 19 with high grain yield and low G×E interaction were selected as stable and adaptable durum wheat genotypes. Each of them is superior in on-farm condition, will be introduce as a new durum wheat cultivar for temperate zone of Iran.

Introduction:

Durum wheat (Triticum turgidum L. var durum) consists of only 5% of the world’s total cultivated wheat area and contributes about 10% to the total global wheat production. In recent years, the production level of durum wheat has risen to more than 30 million tons and EU, USA and Canada together representing 60% of the production. Durum wheat in Iran is grown on 300-400 thousand hectares with an average annual production of 500-600 thousand tons. Increase in yield is one of the primary aims pursued in plant breeding programs. Similar to other crops, insufficient yield stability in durum wheat is recognized as a one of the factors responsible for the gap between actual yield and potential yield. In breeding programs, the identification of superior genotypes is difficult due to environmental variability of target locations and the interaction of these variability with the investigated genotypes. Therefore, it is important to evaluate the advanced agronomic lines across various environments and over multiple years to ensure their yield stability and production. Many statistical models have been suggested to analyze G×E interaction. The additive main effects and multiplicative Interaction (AMMI) model is a multivariate statistical method that entirely justifies genotype and environment main effects as well as multiplicative G×E interaction effects. This method provides a clear interpretation of G×E interaction effect. The objectives of this study were to analyze genotype by environment (GE) interactions on the seed yield of some durum wheat lines by AMMI model and to evaluate genotype (G), environment (E) and genotype× environment (GE) interactions using statistics parameter i.e. AMMI stability value (ASV) and ecovalence (W2i).

Sixteen promising durum wheat lines (G1-G16) along with two check cultivars (durum wheat cv. Hana and bread wheat cv. Parsi), were investigated for two cropping seasons (2015-2016 and 2016-2017) at three Agricultural Research Stations (such as Karaj, Kermanshah and Neishabour cities) The experimental design at all locations was a randomized complete block design with three replications. Some agronomic attributes such as the number of days until anthesis stages, plant height, number of days till physiological maturity, 1000-kernel weight and grain yield were determined for each genotype. However, only the grain yield data was used to analyze G×E interactions. Combined analysis of variance for grain yield was performed using ADEL-R software. The GGE Biplot methodology was employed to analyze G×E interaction. The AMMI M model was used for the following purposes; (i): Evaluation of yield stability, (ii): The simultaneous selection for yield and stability, (iii): Identification of ideal durum wheat genotypes, and (iv): Assessment of the characteristics of and relationships among the testing environments.

The combined analysis of variance showed that the main effects of year and location were significant at 1% probability level, while the main effect of genotype had not significant. Genotype× year interaction and triple genotype × year × location interaction were significant at 1% probability level and also genotype × location interaction was significant at 5% probability level, indicating genotype × environment interaction. The results of AMMI ANOVA showed that about 86.5% of total variation was related to environment effect, 1.4% to genotype effect and 12.1% to genotype× environment interaction. Overall, the average grain yield of the evaluated lines ranged from 7.6 to 8.4 t.ha-1 and the G18 and G2 lines had the lowest and highest grain yield, respectively. Main effect due to environment and genotype × environment interaction as well as two first interaction principal components (IPCA1-2) were found to be significant, indicating that the agroclimatic environmental conditions were different, and that there was a differential response of the genotypes to the environments. The first two IPCA components of the GE interaction explained about 70.2% of the GE interaction. According to IPCA1, G9, G15 and G16 had the lowest scores and were the most stable genotypes whereas G17 and G18 with the highest scores were found to be unstable. The lowest ASV was observed for G16 that was the most stable genotype whose mean yield was higher than the grand mean. However, the highest ASV scores were achieved by G17 and G18. AMMI Biplot was used to visualize mean seed yield performance and stability of durum wheat genotypes. AMMI Biplot was able to distinguish stable genotypes with broad sense and narrow sense adaptation and environments with high and low genotype discrimination ability. The genotype G16 with higher seed yield than the total mean were the most stable genotypes, while the genotypes G17 and G18 with the highest contribution to GE interaction were the most unstable genotypes. Wricke’s ecovalence stability parameter (W2i) showed that the genotypes G16, G12, G5 and G4 were the most stable genotypes.

The results indicated that AMMI model and their biplots was an appropriate method for simultaneous selection of performance and stability of cultivars and lines. Also, according to all of methods, genotype G16 was selected as a stable and high genotype across all environments. Finally, it can be considered as a favorite promising line compared to the check cultivar Hana and as a candidate in the temperate climate.

Durum wheat (Triticum turgidum L. var durum) consist of only 5% of the world’s total cultivated wheat area and contributes about 10% to the total global wheat production. Durum wheat in Iran is grown on 300-400 thousand hectares with an average annual production of 500-600 thousand tons. Similar to other crops, insufficient yield stability in durum wheat is recognized as a one of the factors responsible for the gap between actual yield and potential yield. In breeding programs, the identification of superior genotypes is difficult due to environmental variability of target locations and the interaction of these variabilities with the investigated genotypes. Therefore, it is important to evaluate the advanced agronomic lines across various environments and over multiple years to ensure their yield stability and production (Yan & Rajcan, 2002). Many statistical models have been suggested to analyze genotype (G)× environment (E) interaction. GGE (genotype plus genotype-by-environment) biplot method is a multivariate model, which is based on principal component analysis that simultaneously represents G, E and G×E interaction on a graph known as biplot. GGE biplot is widely used in agricultural research as it provides a simple graphical interpretation of G×E interaction. The aim of the study was to evaluate the grain yield stability and adaptability in some promising durum wheat lines grown in moderate regions of Iran.

Eighteen promising durum wheat lines (G1-G18) along with two control cultivars (durum wheat cv. Hana and bread wheat cv. Parsi), were investigated based on a randomized complete block with three replications for two cropping seasons (2016-2017 and 2017-2018) at four Agricultural Research Stations (including Karaj, Ahwaz, Kermanshah, Neishabour and Isfahan cities, Iran). Combined analysis of variance for grain yield was performed using ADEL-R software. The GGE biplot methodology was employed to analyze G×E interaction (Yan, 2001). The GGE biplot model was used for the following purposes; (i) evaluation of yield stability, (ii) the simultaneous selection for yield and stability, (iii) identification of ideal durum wheat genotypes, and (iv) assessment of the characteristics of and relationships among the testing environments.

About 70% of variation was related to environment, 1.7% to genotype and 13.5% to genotype× environment interaction. Overall the grain yield of the lines ranged from 6.57 to 7.26 t.ha-1 and the G20 and G2 lines had the lowest and highest grain yield, respectively. Also, G6 and G16 lines had higher yield than Dena cultivar (G1). Surveying Polygon of GGE biplot showed that genotypes G2, G16, G5, G4, G20, G8 and G6 which had the most distance from Bipolt center and located in Polygon vertices that they were premier genotypes. The lines which designed from Biplot center divided the shape of Polygon to four environments. The first environment was included into the Isfahan in which genotype G6 had the most performance. The second environment was included into the Karaj that G2 was premier genotypes of this environment. The third environment was included into Kermanshah that genotype G16 was high performance genotype in this environment. The fourth environment was included into the Neishabour in which genotype G20 was premier genotype. The G12, G3, and G10 genotypes, which were located near the center of the biplot, had performance in all environments. Simultaneous evaluation of grain yield and stability through environment coordinate (AEC) biplot showed that genotypes G2, G1 and G18 with the higher grain yield were the most stable genotypes. There were many similarities between Karaj and Kermanshah environments as well as Karaj and Isfahan. The angles between these two environmental groups were less than 90 degrees. In contrast, the angle between Neishabour environment and Kermanshah and Karaj environments was distorted and near 180 degrees. These results verified the Karaj station was close to the ideal environment. G2 and G16 genotypes were identified as favorable genotypes in Karaj environment.

GGE Biplot was an appropriate graphical method for simultaneous selection of performance and stability of cultivars and lines. Based on the results, genotype G6 in Karaj, G6 in Isfahan and G20 in Neishabour were the best genotypes in terms of yield and stability. Generally, G18 can be considered as a favorite promising line compared to the control cultivar Hana and as a candidate in the temperate climates.

In order to investigate the effect of spreading time and application rates of wheat straw as mulch on Saffron corm and flower yield, a field experiment was conducted as factorial layout based on randomized complete block design with three replications at Gonabad Agricultural and Natural Resources Research Station, Center for Research and Agricultural Education and Natural Resources of Khorasan Razavi in years 2015-16. The treatments were all combination of wheat straw in four levels (2, 4, 6 and 8 t.ha-1) and time of wheat straw spreading in three dates (22 June, 6 July and 23August). The results showed that the rate and time of straw application and their interaction had significant effect on all studied characteristics of saffron flower. Spreading of wheat straw at 22 June compared to 6 July and 23August had the highest significant effect on increasing flower number, fresh flower yield, dry stigma and style yield (up to 41.7, 16.9 and 50 percent, respectively). In addition, all studied criteria of saffron replacement corms were significantly affected by the time of wheat straw spreading, different levels of wheat straw application and their interactions. Among the studied treatments, the highest corm yield in terms of more than 8g (595.65 g) and total saffron replacement corms yield were obtained in applying 8 t.ha-1 wheat straw at 22 June (1163 g). Compared to the treatment of 2 tons per hectare, the remnants on the same date show an increase of 112.2 and 12.9 percent, respectively.

Identification of adapted genotypes with high grain yield is the most important goal in durum wheat breeding programs. To study adaptation and grain yield stability of durum wheat genotypes, 18 durum wheat promising lines with two commercial durum and bread wheat cultivars were used. The durum wheat genotypes were evaluated in four locations; Isfahan, Karaj, Kermanshah and Neishabour in temperate agro-climate zone of Iran in 2013-14 and 2014-15 cropping cycles. The experiments were conducted using ranodomized complete block design with three replications. Combined analyses of variance were performed for grain yield. The genotype and genotype × year × location effects were significant. Therefore, for more precise evaluation of genotype by environment interactions and grain yield stability, parametric and non-parametric analysis methods such as AMMI, rank and standadard deveiation (SD) of rank, coefficient of environmental variation was employed. Results of all three stability analysis methods showed that genotypes no. 3 and no. 4 with high grain yield (8650 and 8699 kg.ha-1, respectively) and low G × E interaction were adapted with grain yield stability durum wheat genotypes. These superior durum wheat genotypes were identified for being released as new commercial durum wheat cultivars for temperate agro-climatic zone of Iran.

    Tillage and preparation of soil, alone account for a significant part of the crop production costs, which according to statistic of Ministry of Jihad-e-Agriculture in 2015, about 9% of the total cost per hectare of wheat (28 million Riyal) has been allocated to plowing and discs. Therefore, in order to reduce costs, energy consumption, equipment depreciation, saving during operation, maintaining the environment and sustainability of the production system, the approach to low tillage and no tillage has grown further. However, the development of these methods is accompanied by barriers that can be largely categorized into three broad categories: access to machinery, social barriers and economic issues. Farmers are worried that reducing the income resulting from the elimination of some inputs, especially tillage is more than reducing its costs. Here are two points that affect farmers' decision-making: One is which crop rotation is sustainable for sustainable farming? And the other is which sustainable crop rotation, can serve the economic interests of farmers? The past studies have shown that in agronomic rotations, because of the variety of products, it is necessary to evaluate the treatments in order to select the best alternatives. In addition, in conservation methods, reducing production costs cannot be a reason for the superiority of treatments with minimum tillage and it is necessary to evaluate these treatments economically.               This research was carried out with the aim of evaluating the economic efficiency of conservation agricultural system and comparing it with conventional agricultural practice in two crop rotations include  conventional and sustainable systems. Experiments were conducted using a split-plot design based on randomized complete block with three replications in research station of Torogh Mashhad during 2011-16 growing seasons. Main factor was three tillage methods include 1-Conventional Tillage: Plow + Disc + Leveling + Faro + Seed planter, (CT), 2-Reduced Tillage : Disc +Faro + Seed planter, (RT) and 3-No Tillage: direct plant by Seed planter (NT)) were allocated in main plots and three residue management (Zero (R0), 30% (R1) and 60% (R2) of residue retention) were assigned in sub plots. Experimental treatments were compared and valuated  by using partial budgeting method.            Results showed that sustainable crop rotation, SCR, has a higher overall production value than conventional crop rotation, CCR,. The ratio of the production value of SCR to CCR is between 1.64 to 2.1 and 1.8 on average, and the ratio of costs is almost 1.08, but the net profit ratio of SCR to CCR is from 1.9 to 2.6 and 2.1on average. However, the difference between cost of two crop rotation is almost 8%, but the difference in their water consumption is 3% (71400 cubic meters in the CCR versus 73695 cubic meters in the SCR), in other words, in the SCR The value of production per cubic meter is 56159 Rials, in the event that in the CCR is 27157 Rials. Increasing tillage, increase the benefit of treatments. Nevertheless, increasing in residue retention in NT, decrease benefit. Although, in RT and CT increasing in residue retention to R1 increase and to R2 decrease benefit. Therefore, in RT and CT, economical treatment is R1. In the CCR, the highest net income and rate of return treatment was CT + R1. In the event that in SCR, the highest income and the lowest cost  treatment was NT + R0. In the CCR, the treatment of CT + R1, with the net benefit of 246371580 Rials and a rate of return, ROR, 437%, had the highest net benefit and ROR. In the event that in the SCR, the treatment of NT + R0, with the net benefit of 450020790 Rials had the highest income and the lowest cost. These results indicate that applying conservation agriculture in the CCR isn’t economical. But if the crop rotation changes, then the conservation agriculture in the field of no tillage is economical, and isn’t for residue retention. ConclusionResults showed that SCR has a higher overall production value than CCR. In the CCR, the highest net income and rate of return treatment was CT + R1. In the event that in SCR, the highest income and the lowest cost  treatment was NT + R0.

Hana (DM-90-14) was selected from international durum wheat nurseries with grain yield of 7547 kgha-1in cropping season 2009-10. This line was assessed in the regional yield trials in four cropping seasons,from 2009 to 2013, in four locations of temperate agro-climate zone of Iran. Hana had a grain yield of 9666 and 6768 kgha-1 in preliminary and advanced yield trials, respectively. In elite regional yield trial in 2011-12 and 2012-13 this line with 7938 kg ha-1 was selected as a superior line based on its grain yield and yield stability. Hana also has a high quality for semolina as well as high protein content (12.1%). The results of on farm trials in Kermanshah showed that this cultivar with grain yield of 8934 kg ha-1was superior than check cultivar, Dena, with grain yield of 6440kg ha-1. Based on its high grain yield, yield stability, quality of semolina and resistance to yellow and leaf rusts, line DM-90-14 released as a new durum wheat cultivar with name “Hana” for temperate agro-climate zone of Iran including Tehran, Alborz, Isfahan, Khorasane Razavi and the north of Kerman, Lorestan, Kerrmanshah and Fars provinces.

Modern agriculture in the world had positive results for human by increasing of food and Prosperity, but had negative effects on nonrenewable resources. This system is based on more consumption of foreign inputs, chemical fertilizers, water and energy. Where traditional tillage and residue removal practices have been used over of Iran, soil has been lost through erosion while the soil resource has been degraded physically, chemically and biologically. As a result, improved or new varieties of crops (such as wheat) as well as use of other inputs are not able to deliver their potential contribution. The term conservation agriculture removes the emphasis from the tillage component and addresses an enhanced concept of the complete agricultural system; it involves major changes in many aspects of the farm cropping operation. Due to the increasing consumption of energy in the world and the decrease of energy resources, it is important to pay attention to the systems that wasting energy in them be at the least. The aim of project was to evaluate the energy efficiency of the protective system of agricultural under two separate systems of crop rotation in two separate experiment, in agricultural and natural resource research education center (station of Torogh, in Mashhad). The experiment was performance using a split-plot design based on randomized complete block with three replications for five years (during 2011-16 growing seasons). Experiment treatments were various tillage methods in main plots,Conventional Tillage (CT: Plowing + disc + leveling + planting with seeder), Reduced Tillage (RT: heavy disc + planting with seeder) and No Tillage (NT: planting with seed).Residue management in sub plots contain, no residue (R0), Maintaining 30 percent of the plant residue (R1) and Maintaining 60 percent of the plant residue (R2). The first crop rotation was conventional as the same of farmer rotations consist of wheat-corn-wheat-melon-wheat. The second crop rotation was more diverse and closed to sustainable rotation inclusive wheat-rapeseed-wheat-clover-tomato-wheat. Results showed that with energy efficiency for both crop rotations (conventional and sustainable) the contribution of human strength was very low and contribution of water and straw each with 30% had the highest level and machine and fertilizer were in the subsequent stage. In both crop rotations, NT + R0 had the highest level of energy efficiency. In conventional crop rotation, increasing of tillage from NT to CT had decreasing of energy efficiency but increasing of tillage from NT to RT treatments increasing energy efficiency slowly.

The previous studies showed that exercise training has been shown to benefit diverse medical and behavioral conditions. The purpose of the current study was to investigate the effect of resistance training on the level of cortisol, testosterone hormone, and some physical fitness factors of males washed out from methamphetamine addiction in rehabilitation period.

A total of 19 washed out males (Age 29.8±4.5 yr) from methamphetamine were randomly divided in to two resistance group (n=10) and control group (n=9). The training group performed eight weeks of training at 50-80 percent of one repetition maximum. Before and after the eight weeks of training, blood sample were obtained to measure serum cortisol and testosterone. Also, participants' muscle strength and endurance and body composition were measured. One-way covariance test and dependent t-test were run to analyze the hypothesis. All data were analyzed using statistical software of SPSS, version 20, and a P-value of P≤0.05 was considered statistically significant.

The results showed that the levels of cortisol has a significant decrease in experimental group (p=0.05), while cortisol levels were not found to be significantly different between the two groups (p>0.05). Testosterone was slightly increased in training group but the increase was not found to be significant (p>0.05). Moreover, the results demonstrated that there were no significant differences between experimental and control groups in testosterone levels (P=0.24). The muscle strength of the upper extremity and muscle endurance, and the circumference of the chest, arm, and waist of the experimental group had a significant increase compared with those of the control group, too (P=0.01).

It seems that a period of resistance training for eight weeks can be effective as a non-pharmacological treatment strategy in wash out period related to addiction of previously metamphetamine dependent individuals. Also, it could improve physical and functional status of these persons.

Biopolymers are a class of polymer, which are disintegrated by an enzymatic or bio-path and the products disseminated to the surroundings do not induce negative effects. Nowadays, non-degradable polymers are quid pro quo with biodegradable ones particularly in agricultural applications, environmental and food industry use. Starch is an example of natural biopolymers, biocompatible, which is completely biodegradable in environment. It has been considered as one of the best candidates for oil based polymer substitution due to its low cost, availability and processbility. The main disadvantages of starch based polymers are their high hydrophilic nature therefore; they have poor mechanical properties and are permeable to water vapor. However, these aspects could be considerably reclaimed by shuffling it with nanodimension materials such as itanium dioxide (TiO2) and Montmorillonite (MMT). The main reason for this improvement in comparison with conventional composites is the large surface area of these nanomaterials which results in high interactions between the nanofillers and starch. The functional behaviors of nanocomposite films have been depended to the compatibility and degree of nanoparticles dispersion in the biopolymer matrix. TiO2 is a 3D nanosphere has been perused widely because it is inexpensive, chemical inert and, has a high refractive index with visible and UV shielding potential. MMT as a 1D, platelet is the most commonly used layered silicates. The investigation of biodegradable films containing two different nanofillers simultaneously has been rarely done. TiO2 and MMT as two different inorganic nanofillers have different physical and chemical structures, so simultaneously use of TiO2 and MMT clearly had a new effect on the nanoparticle distribution and functional properties of starch films. The aim of this study was investigate the synergistic or antagonistic effect of combination of TiO2 nanoparticles and MMT platelets on the functional properties such as surface hydrophobicity, water vapor permeability (WVP), moisture uptake (MU), Water Solubility (WS) and mechanical properties of plasticized starch-MMT-TiO2 nanocomposites.
100 ml of potato starch solution with a concentration of 4% (w/v) was prepared by dispersion of starch in distilled water. It was gelatinized at 80 ºC for 15 min. Different amount of TiO2 (0.5, 1 and 2% w/w starch) and MMT (3 and 5% w/w starch) were dissolved in distilled water and added to the gelatinized starch after treatment with ultrasound for 30 min. Glycerol with concentration of 50% (w/w starch) was added to the starch-nanofillers filmogenic solution. Bionanocomposite plasticized starch (PS) films were produced by casting and were dried in an oven at 45 °C for 15 hours. The X-Ray diffraction (XRD) measurements were performed for MMT and TiO2 powder and starch-MMT and –TiO2 nanocomposite films. The methodology of WVP measurements was based on the ASTM E96-05 (ASTM, 2005). Mechanical properties of the films were determined according to ASTM standard method D882-10 (ASTM, 2010). With some modifications, the methods described by Tunc et al., (2007) and Rhim et al., (2006) were used to determine MU and WS, respectively. Water contact angle (WCA) measurements were performed by the sessile drop procedure. The statistical analyses on a completely randomized design and were carried out using analysis of variance (ANOVA). Duncan’s multiple range test (p XRD demonstrated the change of MMT layers dispersion pattern from exfoliation in binary PS-5%MMT films to exfoliation-intercalation in ternary PS-5MMT-TiO2 films. These results showed that TiO2 agglomerates are formed in the starch matrix with MMT level more than 3% wt. This could be due to the interaction between starch and MMT tends to be more favorable than TiO2. Good dispersion of TiO2, high miscibility of with clay, and continuous phase can be obtained when the content of MMT discs is low. Due to the strong interfacial interaction between the starch and MMT, the tensile strength (TS) increased considerably from4.86 to 5.24 MPa, while the elongation at break (EB) decreased significantly from 78.23 to 71.93%, As the MMT concentration varied from 3 to 5%. The TS of nanocomposite films were further improved after the incorporation of TiO2. Suitable dispersal of TiO2, and creation of new interactions in the PS-MMT network, causes to increase the tensile strength of nanocomposites. The TS and EB values of PS-3MMT-1TiO2 nanocomposite film was higher than that of the other films. This is indicative of a synergistic effect between TiO2 and MMT which increases the tensile strength and does not decrease the EB. In the PS-5% MMT films, both mechanical characteristics were reduced. WVP shows more evidences of synergistic effect of combination of 1D MMT and 3D TiO2 on starch films. WVP reduction by MMT has been attributed to tortuous pathway which created by clay layers in the starch matrix. MMT platelets are water vapor impermeable, thus exfoliation of MMT reduce the voids in starch matrix. The PS-3MMT-2TiO2 nanocomposite showed the lowest WVP as compared to other PS films. WVP was reduced significantly from 5.84 × 10-7 g/m.h.Pa in the PS-3%MMT binary film to 3.04 × 10-7 g/m.h.Pa in the PS-3%MMT-2%TiO2 ternary film. TiO2 have low water solubility and hydrophobicity compared with starch and MMT. Thus, significant decrement of WVP in the prophase of TiO2 connoted that TiO2 was obstructing the nano- and micro-pathways in the PS films network. With addition of MMT and TiO2 content the water solubility and moisture absorption were reduced significantly. Results of water contact angle test confirmed the results of moisture absorption, solubility in water and water vapor permeability and showed that the addition of TiO2 increased the surface hydrophobicity of starch-MMT films as with addition of 2% titanium dioxide in PS-3% MMT and PS-5% MMT films, the contact angle after 60 seconds increased 4 and 15 degree respectively. As a result, 1% wt TiO2 nanoparticles (FDA maximum allowable) can be regarded as the optimum concentration and the developed starch based nanocomposite films can enable undertaking applications as appropriate candidates in food packaging systems.

In the present study, potato starch nanobiocomposites films plasticized with glycerol and containing four different montemorrillonite loading (0, 1, 3 and 5 wt% starch) were prepared via solution casting method. Differential scanning calorimetry (DSC) confirmed that the melting point and glass transition temperatures were increased and heat stability of the nanocomposites were improved. Upon 5% MMT loading, the glass transition and melting point of PS film were increased from 185.6 and 282.9 to 203.5 and 304.6, respectively. Colorimetry and UV-Vis spectroscopies were employed to evaluate the UV and visible-shielding efficiency of the PS-MMT nanocomposite films. Incorporationof 5% MMT did not have significant effect on color parameters (L*, b* and a*), color differences (E) and whitness index, but decrease yellow index of the films. Presence of 5% MMT in film formulation successfully blocked more than 82, 38 and 11% of UV-A, UV-B and UV-C lights, while opacity and transparency of the films were unchanged. Investigation of chemical structure of nanobiocomposite films by Fourier-transform infrared spectroscopy (FT-IR) and Atomic force microscopy (AFM) and revealed the hydrogen bonds interactions between MMT and starch and uniform dispersion of MMTplatelets in the starch matrix, respectively. Also, AFM topography images were used to study the surface morphology and roughness of starch films. Plasticized starch (PS) film had smoother surfaces and a lower roughness parameter. Adding MMT to starch matrix caused to increase the average roughness (Ra) and the most frequently quantitative parameters of roughness (Rq) from 32.4 nm and 39.9 nm in PS film to 119 nm and 147 nm in PS-5%MMT, respectively. The AFM phase images described the uniformity of the starch-MMT mixtures.

In this study, we modeled the simultaneous heat and electricity transfer in a solid-liquid two-phase system in order to determine the critical factors affecting the ohmic heating process. In this modeling, by considering the static fluid model of De Elwis and Fryer, a two-dimensional simulation was done by the commercial COMSOL software in order to investigate the effect of the particle size on the rate of phase heating. So, a solid particle with a lower electrical conductivity comparing with its surrounding liquid, was used to determine the ohmic heating properties of the solid-liquid mixture in two different cross-sections .The dispersed phase consisted of a cylindrical piece of potato with two different sizes and the fluid consisted of a 5% solution of carboxymethyl cellulose (CMC) at 5.0% sodium chloride. The results showed a good approximate agreement between the results of the simulation model and the experimental results. The heating rate decreased with increasing the particle size and conformed to the Worst-Case phenomenon which was used as a non-ideal circumstance in the two-dimensional simulation in the current research. The coldest point was in the center of the particle and as the time proceeded, it remained the coldest and as the distance from this point increased, the temperature increased. It can be concluded that the influence of heat and electricity throughout the heating process is faster than conventional methods of heating and occurs in both liquid and solid phase uniformly and almost with the same speed.

Biodegradable films for food packaging applications have attracted an increasing amount of consideration over the last two decades, predominantly due to environmental pollution and the realization that our petroleum resources are not infinite. Starch, which is one of the natural biopolymers, has been considered as one of the best candidates primarily because of its processbility, availability and price. The main disadvantages of starch films are their pronounced hydrophilic character therefore; they are permeable to water vapor and have usually poor mechanical properties. However, these features can be significantly improved by blending with nanodimension materials such as Montmorillonite (MMT) and Titanium dioxide (TiO2). The main reason for this improvement in comparison with conventional composites is the large surface area which results in high interactions between the nanofillers and polymer when these nano-materials are well dispersed. The behavior of nanocomposite films has been depended to the dispersion of the nanoparticles in the polymer matrix. MMT as a one-dimensional (1D) material is the most commonly used layered silicates. TiO2 as three-dimensional (3D) nanoparticle has been investigated most widely because it is inert, inexpensive and, has a high refractive index with UV shielding potential. The study on films with different dimensions of nanofillers simultaneously is rarely reported. MMT and TiO2 as two inorganic nanofillers have different shapes and structures, so the combination of TiO2 and MMT apparently had a synergistic effect on the starch film properties. The aim of this study was to control particle agglomeration and investigate the synergistic effect of combination of TiO2 nanoparticles and MMT layers and on the surface topography, color, and thermal properties of plasticized starch-MMT-TiO2 nanocomposites.
.First, 100 ml of potato starch solution with a concentration of 4% (w/v) was prepared by dispersion of the starch in distilled water and was gelatinized at 80ºC for 15 min. Different levels of MMT (3 and 5% w/w starch) and TiO2 (0.5, 1 and 2% w/w starch) were dissolved in distilled water and were added to the gelatinized starch after treatment with ultrasound for 30 min. Glycerol, as a plasticizer, with concentrations of 50% (w/w starch) were added to the filmogenic solution. The plasticized starch (PS) based filmogenic solutions were dried in an oven at 45 °C for 15 hours. The surface roughness and topography and thermal properties of the films were determined through atomic force microscopy (AFM) and differential scanning calorimetry (DSC) analysis, respectively. Fourier transforms infrared (FTIR) spectroscopy in the range of 4000 to 400 cm-1. UV-Vis spectroscopy was employed to evaluate the absorbance and opacity behavior of the PS-MMT-TiO2 nanocomposite films in the wavelength range of 200-800 nm. The color parameters of films were measured by a portable colorimeter. Statistical analysis was performed on a completely randomized design with the analysis of variance (ANOVA) and Duncan’s multiple range tests was used to detect differences among the mean values of the films properties
Atomic force microscopy’s images demonstrated an obviously uniform dispersion of MMT and TiO2 nanomaterials in the PS-3%MMT-TiO2matrix with smoother surfaces and a lower roughness parameters than that for the corresponding binary PS-MMT nanocomposites with the MMT filler content (3 wt%). Surface roughness of starch films was changed depending on the MMT and TiO2 content. The results of the roughness parameters and topographic images were confirmed by the high frequency distribution curves. In the PS-3 and 5% MMT films, most parts have height of about 400 and 600 nm, respectively; While the height of the PS-MMT-1% TiO2 bionanocomposites film were 200 and 800 nm. FTIR revealed the hydrogen bonds and electrostatic interactions between nanofillers with starch and themselves by the peaks associated with bond C-O-H at 1142 cm-1 and 990 cm-1 and wide and high intensity IR absorption in the 500-800 cm-1.Evanescence of 3626 and 3452 cm-1 peaks assigned to OH groups of MMT in the PS-3MMT spectrum affirmed the interaction between starch and MMT.Shift in melting temperature and glass transition (Tg) towards higher temperature respectively from 295.1C to 306.3 C and from 199.1 C to 207.6 C were illustrated by DSCresults due to addition of TiO2 in the PS-3%MMT matrix.Improvement of thermal stability might be attributed much jammed and conjugated 3D MMT-TiO2 network combined together, or powerful interaction between PS and nanofillers could also slowdown the polymer chains motion and melting point during heating. These results showed a significant effect of combination of 1D MMT layers and 3D TiO2 nanoparticles on the thermal properties of PS nanobiocomposite starch based films. Montmorillonite did not affect color of nanocomposite. The transparency of a nanobiocomposite film is not significantly varied when the clay layers with about one nm thick are excellent dispersed through the polymer matrix, since such MMT platelets are less than the of visible light wavelength and do not block lights transmission. Transmittance, redness and yellowness of new ternary films decreased when TiO2 was added to PS-3%MMT matrix at 1%. In this case, color difference (ΔE) and whiteness index (WI) are increased 86.6% and 76% respectively.Starch and PS-MMT films were colorless. The presence of TiO2 imparted whiteness to the nanocomposites due to its inherent whiteness. This phenomenon can be enucleated as the large specific surface area and high refractive index of nanosized TiO2 particles were accounted or diffuse reflection of light from the interface of the materials, and consequently, transparency loss of the composite films. UV-Vis spectroscopy was employed to evaluate the absorbance and opacity behavior of the PS-MMT-TiO2 nanocomposite films in the wavelength range of 200-800 nm. Incorporation of TiO2 nanoparticles into the starch film solution caused a significant decrease of transmittance in visible, UV-A (360 nm), UV-B (300 nm), and UVC (240 nm) regions. The results of UV-Vis spectroscopy showed that this type of films could be used as a packaging material to shield against UV and visible light.

Development of wheat cultivars with high and stable yield for different environments is very important in breeding programs. In this study, 19 winter and facultative wheat genotypes along with a check cultivar (c.v. Shahreeyar) were studied for grain yield and its stability at Karaj, Arak, Ardebil, Hamedan, Mashhad, Jolgeh Rokh and Tabriz Agricultural Experimental Stations in 1997-2000 cropping seasons. The experimental design was RCB with four replications. Results of combined ANOVA showed that interaction of genotype x location x year was highly significant. Using different stability analysis methods such as CV, regression analysis and simultaneous selection for yield and stability showed similar results. Genotype C75-5 (OWL 85256*-3oh-*O-*Eoh) was determined as the superior for grain yield among all genotypes in almost all methods. Results of the study on harvest index (HI) indicated that the genotype C-75-15 (Bez- 2B/Cgn/Vratza) was superior for HI stability. Although, the correlation coefficient between grain yield and harvest index was positive and significant (r =0.36**) however, stabilities of these two traits among the genotypes, were not similar.