JWSS - Journal of Water and Soil Science

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Effect of different times and levels of nitrogen fertilizer application on growth and grain yield of spring wheat cultivar “Ghods” was studied during 1993-1994 growing season at Karkadj, Agricultural Experiment Station, College of Agriculture, University of Tabriz, using a split plot design with three replications. Main plots were assigned to five levels of N fertilizers (0, 40, 80, 120 and 160 kg/ha) and subplots to five times of applications [all of N fertilizer at planting (T^₀) 1/2 at planting + 1/2 during tillering stage (T₁), 1/2 at planting + 1/2 during heading stage (T₂), 1/3 at planting + 1/3 during tillering and 1/3 at heading stages (T₃) and 1/4 at planting + 1/4 at tillering + 1/4 at stem elongation and 1/4 at heading (T₄)]. Results showed that different levels of N applications affected grain yield and biological yield significantly, while the effect of split application and also N levels × times of application interaction on these two traits were non-significant. Growth stages of wheat were not significantly affected by different N Levels and times of application. Dry matter accumulation, leaf area index, and crop growth rate, in response to growing degree days during growing season, increased when higher levels of N fertilizer were applied. Leaf area index and crop growth rate initially increased up to anthesis and then decreased. Crop growth rate decreased to zero level at soft dough stage and then became negative. Variations in relative growth rate and net assimilation rate, in relation to growing degree days, decreased when different levels of N fertilizer were applied at early part of growing season it was maximum while at later growth stages decreased and finally became negative, Times of N application and level × time interaction during growing season did not affect the growth indices significantly.

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Immature embryo culture response of 28 durum wheat (Triticum turgidum var. durum) cultivars was studied using MS medium in Tissue Culture Laboratory of College of Agriculture, Isfahan University of Technology. Donor plants were grown in a recirculating hydroponic system and pots in a greenhouse. Regenerated immature embryos were recorded at 2, 4, 8 and 16 days after inoculation. Assessment of durum wheat cultivars for immature embryo culture was conducted by percentage and rate of regenerated embryo, using a split plot design arranged in completely randomized design with 5 replications. The analysis of variances showed that there were highly significant differences among cultivars for plant regeneration capacity. The highest potential and rate of embryo regeneration (two days after inoculation) were observed in “Shahivandi” which is a native cultivar of west Iran. “Awl1/Sbl4” with a mean of 48.5%, “Hagla” and “Ofen/Kil” with a mean of 80% have the poorest and the best mean of regeneration during the recording period, respectively. The high regeneration potential is important in view of reducing the time constrain and somaclonal variation in a breeding program.

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In vitro salt tolerance of 28 cultivars of durum wheat with native and exotic origins was investigated, using MS medium containing sodium chloride. The resulting calli were subjected to 8 salinity levels including 0, 0.3, 0.6, 0.9, 1.2, 1.5 and 1.8 percent NaCl (w/v). Donor plants of explant (immature embryo) were grown in a recirculating hydroponics and pots in a greenhouse as well as in the field. Assessment of calli was conducted after 0, 8 and 16 days after subculture of calli into the NaCl-contained medium. Callus growth rate, relative callus growth rate and percentages of callus necrosis were measured, using a 8 × 28 factorial experiment layout in a completely randomized design with 3 observations per treatment and 3 replications. Results of analysis of variances showed that among the criteria, relative growth rate of callus was the most reliable, while callus growth rate as not being quantitatively measured, was less devoted. Results of this study revealed that 'PI 40100' and 'Dipper-6' were superior genotypes for in vitro salt tolerance. The high relative callus growth rate and less callus necrosis of these cvs. may indicate their superior genetic potential for in vitro salinity tolerance.

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Combining herbicides for controlling broadleaf weeds and grasses in wheat farms has not been studied under Isfahan environmental conditions. Thus, this experiment was conducted in 1995-96 at the Agricultural Research Station, Isfahan University of Technology, in order to investigate the issue. In this study, 2,4-D+MCPA (U46 Combi Fluid 6), bromoxynil, metribuzin, diclofop-methyl and tralkoxydim and their combinations in 11 treatments plus weed-free and weedy checks were evaluated using a randomized complete block design with 4 replications. Goldbachia laevigata and Avena fatua were the dominant weeds. Cirsium arvense and Convolvulus arvensis were of less importance. Efficacy of bromoxynil on annual broadleaf weeds was higher than 2,4-D+MCPA, while 2,4-D+MCPA was more effective on perennial broadleaf weeds. Diclofop-methyl and combination of bromoxynil with tralkoxydim were the most effective on A. fatua, while differences between treatments containing diclofop-methyl or tralkoxydim on decreasing A. fatua numbers were non-significant. The most and the least visual damages to wheat plants were caused by metribuzin and bromoxynil, respectively. Wheat yield was not significantly affected by treatments. However, the highest yield was obtained by tralkoxydim + bromoxynil treatment, which produced the lowest total dry weight of weeds at terminal spikelet and heading stages of wheat. The results obtained here indicate that combination of bromoxynil with tralkoxydim might be the best treatment for the control of all annual weeds under conditions similar to this experiment. But if perennial broadleaf weeds and wild oat are dominant in the field, combination of 2,4-D+MCPAwith diclofop-methyl might be preferred.

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Macaroni is a food product generally considered as one of the paste products. These products are produced from semolina that is, in turn, produced through special processing of milled durum wheat. In order to examine the effect of α-amylase on macaroni quality, three cultivars, namely Yavarous, Zardak and Altar 84, were chosen from each of which some wheat sprouts were prepared and mixed with unsprouted samples to obtain three ranges of falling numbers of 500-1000, 300-350 and 150-200 seconds.

The results from this study specified that the active presence of α-amylase in the samples reduced cooking time and colouring of the macaroni, while small amounts of the enzyme improved the breakage and modulus of elasticity of the samples. The α-amylase enzyme showed no effect on the colour of semolina and the macaroni stickiness. 

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This study aims to evaluate land suitability for irrigated wheat in Falavarjan region (Isfahan) using the theory of fuzzy sets. This method differs from the usual land evaluation procedures in its use of weight for different land characteristics and in its method of determining land suitability index. The results were compared with those from parametric land evaluation method. The correlation between land indices and observed yield was higher for the fuzzy set method (r=0.35) as compared to the parametric method (r=0.14). The higher relationship given by the fuzzy set method illustrates its potential usefulness and applicability to land evaluation.

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In order to evaluate the relationship between SDS-sedimentation value and breadmaking quality of wheat (Triticum aestivum L.), glutenin subunits of different genotypes (foreign and Iranian cultivars) were analyzed by reverse-phase high performance liquid chromatography (RP-HPLC). SDS-sedimentation value was used as an indirect criterion for breadmaking quality.

 Correlation coefficients revealed a closer relationship between low molecular weight (LMW) glutenin subunits and variation in SDS-sedimentation value. Principal component analysis confirmed the presence of association between some of the glutenin subunits and SDS-sedimentation value. Based on the stepwise regression analysis, two LMW and four high molecular weight (HMW) peaks (subunits) were selected which accounted for 70.2 and 18.7% of variability in SDS sedimentation values, respectively. On the basis of the results of the stepwise regression analysis, a discriminant function was developed. The great efficiency of discriminant function in correct classification of completely different genotypes (Iranian landraces and cultivars) showed that the observed relationship between glutenin subunits and SDS-sedimentation value has a genetic basis and the effects of LMW and HMW glutenin subunits on SDS-sedimentation value are additive. Therefore, it seems that this method based on more protein components (rather than only on HMW glutenin subunits) can be used to predict breadmaking quality of wheat against many genetic backgrounds.

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Wheat as a main food source is partly lost in different ways such as planting, harvesting, storage and even in consumption processes. This calls for attention to reducing these losses through application of the results from agricultural research, use of new farming practices, improvements in management system and repair and renewal of farm machinery. The present study considers the design, development and evaluation of a new pneumatic air reel system as a replacement for the conventional mechanical reel. To evaluate the new system, laboratory and field tests were conducted.

 In the laboratory tests, the air velocity was measured along the fan outlet width at a 10 centimeter interval from the outlet to 40 centimeters away from it, and corresponding curves of air velocity distribution along the fan outlet width were drawn. On the basis of the results, 13 fans were calculated to be required on the cutting platform of a 14-foot (4.3 meter) combine. The results from the field tests of mechanical and air reels show that grain losses of air reel during harvesting are less than those of the mechanical reel because the air reel has no mechanical contact with the crop and applies less shock on plant stem than the mechanical reel. According to the results, grain losses increased linearly with increasing fan speed. In addition to the change of fan speed (2247, 2503, 2860, 3218 and 3932 RPM), three air discharge directions of 10, 20 and 30 degrees from horizontal line were examined. According to the data analysis in Randomized Complete Block Design (RCBD) through Tukey’s procedure (15 treatments and 6 samples in each treatment), there were significant differences between grain loss at these directions and mechanical reel at a level of 5%. A wind direction of 20 degrees and fan speeds of 2503 to 2860 RPM are recommended.

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To evaluate cold resistance in wheat in laboratory and to find fast and effective methods of evaluation, nine wheat genotypes were studied in three experiments at the College of Agriculture, University of Tehran, Karaj, Iran. Genotypes consisted of four Iranian cultivars, Sabalan, Boulani, Khalij and Naz one Russian cultivar, Bezostaya and four Iranian accessions, 518, 583, 592 and 1255. In experiment 1, genotypes were grown in 10-cm diameter pots and after hardening in the open, their LT50s were determined in cold chamber. Their cytoplasmic membrane stability were also measured at -12°C through electrolyte leakage measurements. In experiment 2, the genotypes were grown in the field to practice hardening in winter then plant crowns were transferred to the lab and their LT50s were determined. Water content of crowns and leaves, sugar content of crowns, and plant erectness were also measured. In experiment 3, water content of crowns and leaves of the genotypes were measured in non-hardened plants.

Cytoplasmic membrane stability, crown water content and crown sugar content of plants showed significant correlations with LT50. Membrance stability had the highest correlation with LT50 (r=0.88). A high correlation was found between crown LT50 of plants taken from field and LT50 from the plants in the lab (r=0.98). It was found that plant water content reduces with cold hardening. Water content reduction was higher in resistant genotypes compared to susceptible ones. There was no significant correlation between crown and leaf water contents with LT50 in non-hardened plants. Bezostaya with LT50=-16.7°C was the most cold resistant genotype and accession 518 with LT50=-8.2°C was the most susceptible genotype, in this study.

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Nitrogen is usually the most limiting nutrient for crop production. Thus, N fertilizer is widely used by farmers. Moreover, Mn deficiency in some calcareous soils of Iran with high pH has been reported. Therefore, the addition of nitrogen and manganese to achieve the optimum yield is necessary. The objective of this study was to evaluate the effect of N and Mn applications on the availability of some soil nutrients under wheat (Triticum aestivum L.), corn (Zea mays L.), and spinach (Spinacia oleracea L.) plants in greenhouse conditions. In a factorial test, five levels of N (0, 50, 100, 200 and 400 mg/kg soil as NH₄NO₃) and three levels of Mn (0, 15 and 30 mg/kg soil as MnSO₄) in a completely randomized design with four replication were applied. Corn, wheat and spinach varieties were sc₇₀₄ Falat and Spinacea spp., respectively. After eight weeks, total N content and DTPA-extractable Mn, Fe, Zn and Cu of soil were measured.

 The results indicated that N and Mn applications increased Mn-extractable of soil in three cultures but didn’t affect the soil total N. Nitrogen application in corn increased available Fe in soil. Mn application decreased extractable Zn and Cu of soil in wheat and soil extractable Cu in corn.

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The variation and path coefficient analysis of bread-making quality traits have been studied for 145 genotypes of breeding lines, cultivars and landrace varieties of wheat (Triticum aestivum L.). Bread-making quality traits of genotypes was evaluated indirectly by protein percentage, SDS and Zeleny sedimentation tests, hardness index, test weight, bread volume, grain moisture, and water absorption percentage. Hardness index, Zeleny and SDS sedimentation tests had the highest coefficient of variability (13.51%, 11.83% and 11.03%, respectively). Factor analysis for the genotypes, based on qualitative traits revealed two factors, which explain 98.23% of total variation and were named grain protein index and bread volume factors. The result of correlation analysis indicated positive and significant relationship between protein percentage, SDS sedimentation test and other bread-making quality traits. On the first and second steps of stepwise regression analysis, protein percentage was the most effective trait in explaining different qualitative trait variations. Path analysis also showed the direct and significant effects of protein percentage, Zeleny sedimentation volume, grain moisture and water absorption percentage, and bread volume on SDS sedimentation test. According to cluster analysis based on qualitative traits, the cultivars and landrace varieties, from the view poit of protein quality and quantity, had the highest potential among other groups (generally breading lines).

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During 1998-99, a field experiment was conducted to investigate the effects of residual Processed Municipal Waste Leachate (PMWL) on growth and yield of wheat (variety Roshan). The treatments consisted of residual amounts of 0, 150, 300 and 600 t/ha of PMWL and a residual N, P, K, and Zn fertilizer treatment in a randomized block design with 3 replications. In 1998, rice seedlings were transferred to 34 m plots. After harvesting the rice, wheat was seeded in the same plots without any new treatment. Processed municipal waste leachate and fertilizers were applied during the rice growth. Residual effects of PMWL increased the amounts of available macro- (N, P and K) and micronutrients (Fe, Cu, Zn and Mn) in soil which, in turn, promoted the grain and straw yield of wheat compared to the control. Straw and grain yield increased from 1.67 and 3.50 t/ha in control to 3.93 and 12.80 t/ha in 600 t/ha of PMWL, respectively. The residual effects of PMWL had no significant effect on heavy metals concentrations in plant. The effects of residual PMWL in the soil were proportional to the amount of leachate applied. However, more investigations are recommended to fully understand heavy metals effects on soil, plant, and environment.

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To study grain quality traits and their relationships with high molecular weight (HMW) and low moleculor weight (LMW) glutenin subunits, 104 durum wheat genotypes were used. Six grain quality characteristics comprising wet and dry gluten content, test weight, grain hardiness, protein content and SDS sedimentation volume were studied. HMW and LMW glutenin subunits were evaluated using SDS-polyacrylamid gel electrophoresis (SDS-PAGE) in 33 genotypes. Statistical analysis including correlation coefficients, factor analysis, cluster analysis of genotypes based on qualitative traits, analysis of variance in qualitative traits based on HMW, LMW, and combination of subunits as well as all of subunits, and canonical correlation analysis between glutenin subunits and qualitative traits were used. Factor analysis of the genotypes detected 2 factors, which explained 65 percent of the total variation among the data. These were named quantitative protein and qualitative protein. Based on cluster analysis, the genotypes were classified into four clusters. The genotypes in groups 2 and 4 were beneficial in terms of protein quantity and quality. In evaluating glutenin subunits, 7 HMW subunits and 2 LMW subunits were detected. Subunit null of Glu-Al was observed. Subunits 7+8, 6+8, 13+16 and 20 at Glu-Bl were observed however, neither of them had significant differences in qualitative traits, but 6+8 and 7+8 had a higher SDS sedimentation rate than 20. LMW-1 and LMW-2 had significant differences in protein content and SDS sedimentation LMW-1 had higher protein content whereas LMW-2 had higher SDS sedimentation. Combibation of subunit LMW-1 / HMW 7+8 had the highest protein content and LMW-2/HMW 7+8 had the highest SDS sedimentation. Results of canonical correlation showed that presence of LMW-2 and HMW 7+8, and absence of LMW-1 and HMW 20 in durum wheats caused an increase in SDS sedimentation and a reduction in protein and gluten content.

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Due to the need for new fumigants to control insects that attack food commodities, the toxicity of acetone was determined on some species of stored pest insects in Urmia University in the year 2000. In empty space tests, the LC₅₀ values of acetone for Oryzaephilus surinamensis (L.), Callosobruchus maculatus (F.), Tribolium confusum (Duv.) and Sitophilus granarius (L.) were 15.40, 15.51, 17.55 and 18.26 μl/liter, respectively. The experiments of acetone penetration to wheat mass revealed that the application of acetone in headspace led to the penetration of acetone vapours into the wheat mass and killing the S. granarius and T. confusum had been concealed in interkernel space. The comparison of LC₅₀ values of empty space tests with LC₅₀ values of penetration experiments revealed that the increase in penetration toxicity was 8.63 fold for S. granarius. A similar trend was observed for T. confusum adults. In hidden infestation tests, the application of acetone to the headspace resulted in destroying the developmental stages of S. granarius concealed in wheat and achieved 75% mortality at a dose of 160 μl/liter during seven weeks. Acetone showed no deleterious effects on the germination and vigor of wheat seeds.

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During the period from 1997 to 1998, samples of wheat leaves were collected from different wheat farms in Fars and Kohgiluyeh & Boyrahmad provinces to identify the causal agent of wheat leaf blight. On the basis of LOPAT tests and production of fluorescent pigment on KB medium, 181 bacterial isolates were recovered from the samples. Based on biochemical, physiological and pathogenicity tests, the isolates were categorized in five groups. One group was found to be Pseudomonas fluorescens (Pf) and the remaining groups were identified as P. syringae pv. syringae (Pss). The pathogenicity test indicated that Pss strains were the causal agent of bacterial wheat leaf blight in Fars and Kohgiluyeh & Boyrahmad provinces. Whole protein electrophoretic patterns were similar in Pss isolates but only a few showed small variation in some subordinated bands. Pathogenic strains of Pss were also isolated from annual and perennial weeds such as foxtail, hairy vetch, oat grass, barley grass and Cynodon dactylon in some areas including Saadat Shahr and Marvdasht. Among the wheat cultivars tested, Tajan was susceptible to the pathogen but others were immune, resistant, moderately resistant, or moderately susceptible. The results showed that Pss is a seed-born pathogen in wheat kernel perhaps as endophyte in the seeds.

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Genetic variation of 300 genotypes of durum wheat comprising CIMMYT/ICARDA and Iranian germplasm was evaluated in 1999-2000 at Researh Farm of College of Agriculture, Isfahan University of Technology located at Lavark, NaJaf-Abad. Days to heading, days to maturity, plant height, spike length, grain weight per spike, number of grain per spike, number of spikes per m², 1000-grain weight, test weight, grain yield, biological yield, and harvest index were recorded. Coefficients of correlation, step-wise regression, factor analysis and cluster analysis of characters and genotypes were conducted using the studied traits. Results indicated that considerable genetic variations exist for the traits and, in particular for grain yield, harvest index, number of spikes per unit area and number of grain per spike. Grain yield had a positive and significant correlation with days to heading, days to maturity, number of grain per spike and grain weight per spike. Factor analysis for the genotypes detected 6 factors, which explained 76.7 percent of the total variation among data. These factors basically involved potential of assimilate distribution, different aspects of plant storage, source-sink relationships, plant height and tillering potential. Cluster analysis was similar to factor analysis in grouping the characters. According to cluster analysis, the genotypes were calssified into 6 clusters with significant differences among all groups. Mean comparisons of traits in these groups showed that genotypes of groups 5 and 6 were superior in grain yield and harvest index and are beneficial to the local durum breeding objectives.

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Azospirillum brasilense is one of the N2-fixing microorganisms which, in symbiosis with the roots of cereals and other graminae, enhances growth and development of plants. In this research, wheat seeds (Triticum aestivum) of three cultivars (Ghods, Roshan and Omid) were inoculated with Azospirillum strains (Sp7 and Dol). Inoculation increased growth parameters and yield of wheat cultivars, the effect being directly dependent on the strain-cultivar combination. Strain Sp7 induced the greatest grain yield, 1000-seed weight, number of grains per spike, root and shoot dry weight in Cv. Roshan, whereas strain Dol stimulated the best effect on these growth parameters in Cv. Ghods. The response of Cv. Omid was lower as compared to the other cultivars. Thus, it may be concluded that compatible strains are necessary for increasing yield and enhancing growth and development of wheat cultivars. These experiments also illustrated similar results regarding the effect of strains on N content of seeds. The observation of nitrogenase activity of Azospirillum strains in the In vitro experiments and the significant increases in N content in some inoculated cultivars support the hypothesis that biological nitrogen fixation by Azospirillum could be responsible for the observed beneficial effects on growth parameters. The comparison of nitrogenase activity of two strains showed that acetylene reduction rate for strain Dol was 1.5 times more than that for strain Sp7. Also strain Dol had more pronounced effects on growth parameters, yield and N content of grains than did strain Sp7. Strain Dol is a local strain whereas strain Sp7 is a Brazilian isolate thus, it may be concluded that the local isolates should be preferred to the foreign bacteria, as they are better suited to traditional cultivars, environment and soil conditions of the region.

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In order to study the nutritive value of grades 1 and 2 wheat feed screening and macaroni wastes as energy resources, 360 21-day-old broiler chicks were divided into 36 groups of 10. In this experiment, each experimental levels of feedstuff was used at 0 (control group), 15, 30 and 45%. In addition, their apparent metabolizable energy (AMEn) was determined by Sibbald’s method. Daily feed intake of chicks fed by diets containing macaroni wastes and grade 1 wheat feed screening for 21 to 56 days of age was significantly lower than that in the control group (P<0.05). In contrast, body weight, daily weight gain and feed conversion had no significant differences during this period. However, in the total experimental period, the best feed conversion belonged to chicks fed with various levels of macaroni wastes and grade 1 wheat feed screening. Apparent metabolizable energy (AMEn) of macaroni wastes and wheat feed screening were 3700, 3270, and 2870 kcal/kg, respectively. According to the results of this experiment, it is possible to use macaroni wastes and grade 1 wheat feed screening at 45% and 30% levels in the diet of broiler chicks, respectively, without any undesirable effects on their performance.

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A factorial experiment with two levels of Zn (0 and 1.5 mg Zn kg^-1), five salinity levels of irrigation water (0, 60, 120 and 180 mM NaC1, and 120 mM NaNO₃) in three replications was conducted. Wheat (Triticum aestivum cv. Roshan) was seeded in pots. After plant harvesting, zinc and cadmium concentrations were determined in the shoot. Activities of metal species in the soil solution were predicted using the computer program MINTEQA2. Treating the soil with NaC1-salinized water increased total concentration of cadmium (Cd_T) as well as Cd²⁺, CdC1⁰₂, and CdCl⁺ species whereas, NaNO₃ treatment had no significant effect on Cd_T. Shoot Cd concentrations were positively related to Cd_T and soil solution Cl^- but negatively related to Zn_T. Application of Zn-fertilizer decreased Cd and increased Zn concentrations in shoot, significantly. The results of this experiment showed that Cl^- has an effective role in increasing mobility of soil Cd and its uptake by plant.

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Russian Wheat Aphid (RWA) is a serious pest of wheat, barely and other small grains in cereal-producing regions of the world. The use of resistant cultivars is an effective management strategy to control this pest. In this study, 15 lines and 13 cultivars of durum and bread wheats along with two resistant and susceptible controls were used to evaluate their reaction to RWA under greenhouse conditions, using completely randomized design with four replications. Three seedlings at each plot were considered as an experimental unit. Five aphid nymphs (4-5 ages) were placed on each plant at 1-2 leaf stage. Leaf rolling and leaf chlorosis percentages were measured 21 days after infesting and used to screen the genotypes. Despite the relatively high linear correlation between two resistance components, leaf rolling and leaf chlorosis, estimated as 80%, analysis of variance indicated significant differences among genotypes. Eight durum lines DW9, DW14, DW4, DW2, DW7, DW8, DW12 and DW3 and one bread wheat cultivar (Azadi) were significantly more resistant than the resistant control (Halt). One durum line (DW13) and two bread wheat cultivars (Shiroodi and M-75-7) had higher leaf rolling and leaf chlorosis than the susceptible control (Sholeh). So they were selected as the most susceptible to the biotype of D. noxia. under study. Orthogonal comparison showed that durum lines were more resistant than bread wheat cultivars. These results were confirmed by Cluster Analysis based on leaf rolling and leaf chlorosis.