JWSS - Journal of Water and Soil Science

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To determine the role of endophytes in conferring valuable physiological characteristics on and induction inducing cold tolerance in two species of festuca, an experiment was done at Isfahan University of Technology in 2002. Endophyte-infected and non-infected clones from two genotypes of tall fescue and one meadow fescue were prepared and coded 75,83 and 60 respectively. The clones were exposed to cold treatments at 6, -2 and –10C and compared with control treatment at 20C. After three weeks of cold treatments, relative water content of leaf and crown, cell membrane stability (electrolyte leakage), percentage of membrane damage and finally proline content of leaf were measured. The presence of endophyt caused an slight increase in relative water content of leaf and crown. There was considerably higher proline in endophyte-infected plants compared with non-infected ones in both stress and non-stress conditions. Endophytic fungi had strong effects on maintenance of membrane stability and on the decrease of electrolyte leakage at all temperature levels. Among plant genotypes, 83 preformed better for some characteristics, specially in the presence of endophyte, and showed higher cold tolerance.

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Sewage sludge application on farmland as fertilizer is commonly practiced in many countries. Sewage sludge is rich in macro- and micro- nutrients. However, high concentration of heavy metals in sludge may cause pollution of soil, groundwater and human food chain because of uptake of toxic metals by crops. The objective of this study was to determine residual and cumulative effects of sewage sludge on concentration of Pb and Cd in soil and wheat. Different levels of 0, 25, 50 and 100 Mg ha^-1 of sewage sludge were applied to the soil for four years. To study the cumulative and residual effects of the sewage sludge, applications were repeated on three fourth of each plot in the second year, on one half of plots in the third year and in one fourth of plots in the fourth year. Wheat grown in the plots, after the fourth year, soil samples from the 0-20 cm depth of the different parts of the plots were taken and analyzed. Wheat was also harvested roots, stems and grains were separately analyzed for the heavy metal concentritons. Cumulative sewage sludge application increased OM, CEC, ECe, total and DTPA-extractable concentration of Pb and Cd in soil significantly (P≤ 0.05). Residual sewage sludge in the soil also increased CEC, total and DTPA-extractable concentration of Pb and Cd significantly. Single sludge applications at different rates increased the DTPA-extractable concentrations of heavy metals. In subsequent years with no further sludge application, DTPA–extractable metal concentrations in soil decreased continuously approaching the levels in the control. However, even after four years, DTPA-extractable concentration of Pb and Cd, were still significantly higher in plots which received more than 50 Mg ha^-1 sludge than control. DTPA-extractable concentrations of Pb was closely correlated with total concentrations. Sewage sludge increased concentration of Cd in roots and stems and Pb in grains significantly. Cumulative effects on concentrations of Pb in grains, and Cd in stems were more than residual effects. The results of this study show that cumulative and residual effects of sewage sludge application increased concentrations of heavy metals in soil and wheat.

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This research was conducted at Rsearch Farm of Isfahan University of Technology to evaluate yield stability of 9 Oat (Avena sativa L.) genotypes and Makooi barley, to determine the contribution of each environmental factor to genotype × environment interaction, and to find the most stable yield component in these genotypes. Four Canadian cultivars and 5 Turkish breeding lines were included in this experiment. Three dates of planting (12 Oct. 31 Oct. and 21 Nov.) and three sowing rates (300, 375 and 450 seed m²) were used as 6 environments. In each environment a randomized complete blocks design with 3 replications was used. Grain yield, No. of panicle/m², No. of seed/ panicle, and 1000-grain weight were measured. Result of combined analysis of variance showed highly significant (P < 0.01) difference among genotypes for all the studied traits. Significante differences were observed among environments for all the characteristics except for 1000-grain weight. Grain yield and its components showed highly significant genotype × environment interaction ffects. The ratio of genotype × environment interaction sum of square to total sum of square for grain yield (22.37%) was higher than other traits. Stability analysis based on regression coefficient showed that Boyer cultivar and Line No.28 with nearly b=1 and more than average yields were the most stable genotypes. Pacer cultivar and Makooi Barley had specific adaptations with suitable and unsuitable environments, respcctively. Based on deviation mean square, Boyer cultivar was the most stable one among high yielding genotypes. Tai’s path analysis of genotype × environment interaction showed that V₃ genotypic component (Seed weight) was the most effective component of stability and yield. Boyer with the highest V₃ score was the highest yielding and stable genotype. According to environmtntal component of path analysis, fertilization stage and grain filling period were the most sensitive growth stages to environmental conditions. Therefor, it is not effective to evaluate genotype stability according to V₂ component (seed/panicle). Finally, according to the result of this experiment Boyer with grain yield of 5.8 t/ha and stable response in all environments was selected as a suitable cultivar for breeding programs or introduction for commertial production.

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Half diallel crosses of eight bread wheat cultivars were used to estimate the genetic parameters and types of genetic control for yield and yield components, and to determine the effects of environmental factors on these parameters. Parents and their F2 hybrids were grown in a randomized block design under irrigated and stressed (terminal drought) conditions. For all traits, except for number of spikelets per spike and number of grain per spike, the effect of environment (irrigated v.s stressed) and genotype by environment interaction were significant. The mean square of GCA for all characters was significant in both environments, except for number of fertile tillers in the irrigated condition and grain yield in the stressed conditions. The mean square of SCA was significant for plant height only in the irrigated condition, while for number of fertile tillers and grain yield it was significant in both conditions. The high significant ratios of GCA to SCA mean square indicated the importance of additive genetic effects on controlling plant height, spike length number of grain per spike in both environments and number of spikelets per spike in the stressed condition. The parameter estimation revealed partial dominance gene actions for plant height, spike length and grain per spike in both environments, and number of spikelets per spike in stressed environment, whereas over-dominance gene actions were observed for the other traits in one or both conditions.

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This research was conducted at Research Farm of Isfahan University of Technology to examine the relations among phonologic, morphologic and physiologic traits and their effects on grain yield of 20 oat (Avena sativa L.) genotypes. A randomized complete block design with three replications was used in each irrigation treatment (i.e. irrigation after 70±3, and 130±3 mm evaporation from class A pan). Grain yield had significant and positive correlations with harvest index and relative water content (RWC) in both irrigation treatments and with plant height at maturity in non-stress condition. Also, grain yield had significant and negative correlation with days to heading. Factor analyses resulted in three factors in each condition, which were named yield factor, phenologic factor and sink factor in both conditions. Based on stepwise regression, harvest index was the first character which entered the grain yield model in both conditions. At the next step, RWC and plant height entered the model, with harvest index explaining 66% and 64% of yield variation in stress and non-stress conditions, respectively. The results of path analysis in both conditions showed that harvest index had the highest positive direct effect on grain yield. The highest indirect negative effects through number of grain per panicle were obtained for the harvest index and panicle m-2 in stress and non-stress conditions, respectively.

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Half diallel crosses of nine Iranian wheat cultivars were used to estimate the general and specific combining ability effects and other genetic parameters related to yield and its components. Parents with F2 generations were evaluated at Research Farm, College of Agriculture, University of Shahrekord, in a randomized complete block design with 3 replications. Partitioning of genotypes mean squares to GCA and SCA mean squares based on Griffing’s method 2 and mixed model indicated high significant differences among cultivars in their GCA values for all traits. There were significant differences among crosses in their SCA values for all traits except for flag leaf length, main spike length, plant height and grain yield per plant. The high ratio of GCA to SCA mean squares implied the importance of additive gene effects in the appearance of flag leaf length , main spike length, plant height and grain yield per plant. For flag leaf width, grain number per main spike and peduncle length , the contributions of additive gene effects and for peduncle weight, the contributions of non- additive gene effects were higher. According to the estimates of average degree of dominance, the gene actions for flag leaf length, flag leaf width, plant height, grain yield per plant, main spike length, peduncle length and peduncle weight were partial dominance. The GCA effects indicated that Sefid – Aliabad cultivar was the suitable general combiner for flag leaf length , flag leaf width, plant height , grain yield per plant , main spike length and peduncle length.

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Inheritance of physiologicaly related salt tolerance traits including Na⁺ and K⁺ contents, K⁺/Na⁺ ratio of young leaves and biological yield (BY) in six basic generations (P₁, P₂, F₁, F₂, Bc₁ and Bc₂) and their reciprocal crosses derived from crosses between Kharchia × Niknejad and Shorawaki × Niknejad were studied in sand culture under high salinity treatment (EC = 22.5 dS m^-1). Generation means analysis indicated that a simple genetic model (including additive and dominance effects) is sufficient for Na⁺ and BY in Kharchia × Niknejad cross and for Na⁺, K⁺/Na⁺ ratio and BY in Shorawaki × Niknejad cross but, for other traits digenic interactions (additive × additive and dominance × dominance) were important parameters in the expression of salt tolerance of the various generations. Dominance genetic effects were predominant genetic components in most of the models. Weighted generation variances analysis suggested that dominance variance component was more important for Na⁺ and K⁺ content in both crosses. This result was confirmed by significant differences between back cross generations. Results also showed negligible dominance for K⁺/Na⁺ ratio in both crosses, multidirectional dominance for BY in Kharchia × Niknejad cross and absence of dominance gene action in Shorawaki × Niknejad. Kharchia × Niknejad cross showed, in general, more genetic variation, broad-and narrow sense heritabilities than Shorawaki × Niknejad cross, indicating the important role of primary differences between parents. These results revealed that recurrent selection followed by pedigree breeding or a selective diallel mating system may prove useful in improving salinity tolerance of wheat plants. The involvement of dominance × dominance interactions for some traits indicates that it is necessary to postpone selection for salt tolerance of wheat to advanced generations, when sufficient epistatic interactions have become fixed.

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  Evaluation of genetic improvement of grain yield and other traits in cultivars released in different years is useful to determine plant breeding impact on grain yield improvement, to define future selection criteria and to identify the desirable environment and traits for further assessment. This study was conducted to evaluate the genetic improvement for grain yield and other traits of twelve oat (Avena sativa L.) cultivars released in Canada during 1921- 1997, at Research Farm, College of Agriculture, Isfahan University of Technology, during 2001-3 in a randomized complete block design with three replications. The regression of mean grain yield on released year of the cultivars showed that the rate of increase in grain yield during a 76-year period is 32.63 kg h^-1 year^-1 or 0.63% per year. Breeding programmes have inereased harvest index, grain number per panicle and fertile tillers /m². The effort of breeders in this period was to decrease plant height and days to heading. The other traits had small changes and showed no specific trends. In general the results of this study showed continous improvement of grain yield in this period. Genetic improvement of grain yield in evaluated cultivars closely correlated with harvest index. Therefore, most variation in grain yield of oats was due to variation in harvest index. Although much of the improvement in grain yield described here could be attributed to the increased harvest index, the scope for further improvement in this character may be limited. Further yield improvement of oats might be achieved by combining high biological yield with high harvest index.

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  This study was conducted at Research Farm of Isfahan University of Technology to evaluate drought tolerance potential of 23 F_2:4 wheat lines derived from the cross of Virmarin (susceptible line) and Sardari (tolerant line). A randomized complete block design with three replications was used in each irrigation treatment (i.e. irrigation after 70±3 and 120±3 mm evaporation from class A pan for non-stress and stress conditions, respectively). Drought tolerance and susceptibility indices were calculated for yield, and principal components analysis was performed on the basis of indices. Rosielle and Hambline tolerance index and Fisher and Maurer stress susceptibility index had positive and significant correlation, but their correlations with drought yield and the first two principal components were negative. High value of these components indicates low sensitivity to drought. The first component had high and positive correlations with geometric mean productivity, stress tolerance index and harmonic mean. Lines number 4, 17, 11 and 14 with high yields in drought condition, showed high values for these indices. Line number 2 with high yield in non-stress condition and in spite of high sensitivity to stress, was a superior genotype based on these indices.

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  The most desirable approach to improve characteristics such as yield with polygenic inheritance and genotype × environment interaction, is simultaneous selection using selection index based on related traits. This study was conducted Research Farm of Isfahan University of Technology, to compare selection indices for barley yield improvement under nitrogen stress and non stress conditions, using 49 F₁₃ recombinant inbred lines derived from a cross between Azumamugi and Kanto Nakate Gold. A split plot design with randomized complete block layout in three replications was used. In non-stress condition 100 kg nitrogen per hectare as urea was used at early reproductive growth, stem elongation and grain filling stages. In stress condition, 50 kg nitrogen per hectare was only used at early vegetative growth stage. Smith-Hazel and Pesek-Baker indices based on 4 traits (days to heading, harvest index, growth rate and nitrogen harvest index) and also direct and correlated response of these traits were calculated. The result of response to selection and correlated response indicated that the selection based on higher harvest index and nitrogen harvest index under both conditions screens high yielding lines. Harvest index had high weight in both indices under stress and non stress conditions. Under both conditions and for Smith-Hazel and Pesek-Baker indices, growth rate had negative correlation coefficients. Therefore, the selection based on these indices, separates lines with lower growth rate. In this study, Smith-Hazel index had higher efficiency.

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Mineralogy is one of the most influential soil properties that change from upper- to lower slope positions, depending on the climate differences. Such changes affect soil properties such as phosphorus sorption and desorption processes differently. Therefore, this study was carried out to investigate the clay mineralogy of soils in four toposequences from arid (Isfahan) and semiarid (Chaharmahal Bakhtiari) regions and its effect on soil P release. The soils of three points on each toposequence were sampled as the upper-slope mainly containing parent materials the mid-slope, non-arable lands and the lower-slope, arable lands. Some of soil properties such as clay minerals were determined. Also, trend of P release parameters was studied in four toposequences. Results showed that the amount of clay, cation exchange capacity (CEC), electrical conductivity (EC), and pH of the soils increase down the slope in all toposequences. X-ray diffractograms showed that kaolinite and illite in upper slope and smectite and chlorite in lower slope were the predominant clays. Among the kinetic models examined based on their determination coefficient and standard error, the Elovich equation was chosen to describe the P release kinetics in studied soils. The trend of P desorption rate along the arid toposequences was in the following order: upper-slope < mid-slope < lower-slope. Furthermore, the rate of P desorption in soils of the semiarid toposequences was higher than arid toposequences. Regarding the trend of P rate parameters along the toposequences, it could be concluded that P release rate and the soil capacity to supply P for plants increase toward lower slope.

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To improve a complex character such as yield with low heritability, the use of indirect selection through other characters and a selection index based on different effective traits is recommended. This study was conducted to evaluate different selection methods by using 23 F2:4 wheat lines derived from the cross of Virmarin (susceptible cultivar) and Sardari (tolerant cultivar) at Research Farm of Isfahan University of Technology. A randomized complete block design with three replications was used in two irrigation treatments (i.e. irrigation after 70±3 and 120±3 mm evaporation from class A pan). For each irrigation treatment, different selection indices were constructed based on the number of spike per m², days to heading, number of grain per spike and 1000 – kernel weight. Also direct and correlated responses were calculated for these traits. The results of the response to selection and correlated response indicated that in the same conditions of this study, early heading cultivars with high number of spikes and low number of grain per spike with high 1000-kernel weight will have more yield potential. Number of spike per m² and 1000-kernel weight exhibited positive response in most of the indices and both irrigation treatments, while days to heading and number of grain per spike revealed negative responses. Thus selection based on these indices would result in early heading cultivars with high spike per m2, low number of grain per spike and high 1000–kernel weight. It was also found that Smith-Hazel and Brim-Williams indices had the highest efficiencies.

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In order to study the genetic diversity of 75 Iranian rice genotypes (45 Iranian land race, 25 improved cultivars, and 5 exotic cultivars) with respect to their salinity tolerance at seedling stage and to determine tolerance indices, based on biomass, genotypic code and Na⁺/K⁺ ratio a factorial experiment in randomized complete block design with three replications was conducted under control and salt stress(1.2, 4 and 8 dSm^-1) conditions at Rasht Rice Research Institute. Root and shoot length, root and shoot dry weight, Na⁺ and K⁺ concentrations, and genetic score were studied. Significant differences were detected among genotypes for all traits. Shoot length and K⁺ concentration had the highest and lowest heritability estimates, respectively. Genetic score under salinity stress showed that Tarom-mahalli, Gharib, Shahpasand Mazandaran and Ahlami-Tarom with more biological yield root and shoot lenghes, and low Na⁺/K⁺ ratio were tolerant. Khazar, Speedroud, IR28 and IR29 were the most sensitive cultivars. Tarommahalli, Ahlamitarom, Rashti and Chparsar had low tolerance index, mean productivity, stress sensitive index, geometric mean index, stress tolerance index and harmonic mean for genetic score, whereas Khazar and Speedroud had high values for theses indices. Cluster analysis, based on seedling traits at 4 and 8 dS.m^-1 divided the genotypes to three groups. Tolerante group had low genetic score and Na⁺/K⁺ ratio, but high root and shoot dry weight, biomass, root and shoot length.

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In order to investigate the diversity and relationship between agronomical traits with seed yield components in barley, twenty advanced barley lines were evaluated in a randomized complete block design with 3 replications at Research Center of Agriculture in Sistan in 2006. Each plot consisted of six rows spaced 20 cm apart and 5 meters long. In this research, 24 Agronomic traits were measured on five randomly selected plants in the central rows of each plot. Analysis of variance showed that there were significant differences among the lines for most of the traits. Line No.7 had the highest (406 grs/m²) and line No.5 had the lowest (309 grs/m²) seed yield. There were high correlation between seed yield and number of panicle/m2. Factor analysis results indicated that 7 independent factors explained 82 percent of the total variation. The first two factors, namely yield components and tillering capacity, explained 41 percent of the total variation. Therefore, it can be concluded that the traits are related to seed yield and tillering capacity, i.e., number of seed per main panicle. 1000 seed weight, number of seed per plant, number of days to physiological maturity and days to heading are the most important characteristics in selecting lines with high seed yield. Number of fertile tiller, total number of tillers and peduncle length were also next set of important traits. Number of days to emergence, nodule number and number of panicle per m² were also important as selection criteria. Seed weight per plant, biological yield, awn length and the traits that were related to flag leaf had lower importance for selection of lines with high seed yield.

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Because of many small florets and protandry, cross pollination in onion which is a biennial plant, by using polycross method for breeding is suitable and easy. To produce polycross seed, bulbs of 9 self onion genotypes were planted in the shape of equilibrium lattice design for 9 treatments with 10 replications on May 2002. To study some agronomical characteristicss, the polycross seeds produced from free pollination and original self-fed seeds (totally 18 genotypes) were planted in plots as a randomized block design with four replications. Samples were taken from each plot and different characteristics were measured. Results showed that polycross generally increased plant fresh and dry weight, plant height, percentage of off type bulbs and yield, with no effect on bulbing ratio and time to ripening. Although polycross increased most agronomical characteristics and yield in Kashan, Azarshahr and Kazeroon genotypes, in some genotypes little increase or even negative effects resulted due to interaction between genotype and polycross. With more assessment of polycross genotypes, good characteristics will be fixed and seeds with higher qualities will be produced.

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Common kilka were chilled during 1, 2, 3, 4 and 5 days to determine the influence of such storage times of fish over the quality of the final canned product. For this propose, common factors for determination of fish quality (moisture, total lipid, free fatty acid, peroxide, thiobarbituric acid and fatty acid profile) were selected and compared with the formation of fluorescence compounds in fish tissue and filling media of canned kilka. In this work common indices showed higher oxidative and hydrolytic rancidity of canned samples compared to raw material but the trend of deterioration with the increase of chilled storage time was not well shown. However, filling media fluorescence compounds was significantly increased with the increase of chilled storage time and the decrease of fish primary quality (P< 0.05). According to the present results, fluorescence detection of interaction compounds can provide a good technique to assess quality differences in the final product as its relates to the quality of the raw material used.

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Many researchers have reported positive effects of converter sludge and slag, two by-products in Isfahan iron melting factory. In this work, the optimum rate of application and the availability of some essential elements (for plant growth) in the converter sludge and slag for corn were investigated. The converter sludge contains about 64% Fe ІІ and ІІІ oxides and some other essential elements for plant growth. The slag also contains 17% iron oxides, 52.8% calcium oxide as well as considerable amounts of some other elements. Treatments included a control, Fe-EDTA foliar spray with 5 in 1000 concentration, application of sludge in 4 levels (L1, L2, L3 and L4 equal to 5.83, 13.33, 20.83 and 26.67 ton/ha, respectively) and application of slag in 4 levels (S1, S2, S3 and S4 equal to 3.20, 7.28, 11.36 and 15.44 ton/ha, respectively) which supply 1, 2, 3 and 4 times as much as soil test recommends, based on AB-DTPA extractable Fe in the soil. Corn (Zea mays) single cross 704 was planted for the experiment. Applications of the two compounds increased the soil extractable Fe and Mn, decreased Mg but the treatment did not change the soil-extractable Zn, Cu and Ca. The corn yield also increased due to the applications of the two compounds and the maximum yield was related to L3, L4, S3 and S4 treatments. The foliar application treated the leaf chlorosis and increased the silage, grain and leaf + stalk yields however, this was not as efficient as sludge and slag application. Also applications of the two compounds increased the Fe, Mn, Zn, Cu, Ca and Mg uptake by corn. The L3 and S3 treatments can be recommended as the proper levels of these compounds as iron fertilizer.

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As the first event in soil erosion, rain splash erosion causes movement of soil fragments. Splash is an important process in interrill erosion. The amount of soil particles detached from the surface is associated with soil and rain characteristics and may be affected by rainfall erosivity and soil erodibility. Therefore, in this study, splash erosion rate and its relation with some soil properties were studied. 120 soil samples were collected from three adjacent land uses including forest, rangeland and agriculture in two depths of 0-10 and10-20 cm in Kasilian Watershed. Soil samples were investigated under the experimental condition using splash cup and rainfall simulator. Results showed no significant differences between splash erosion in different land uses. Cultivated and rangeland soils were found to show a significantly lower organic matter (OM) by 59.93% and 33.62% in depth (0-10cm) and 33.33% and 25.59% in depth (10-20cm), respectively. We also found significance positive correlation between percent of silt and splash erosion rate in agriculture (r=0.69, p=0.018) and significance negative correlation between soil organic matter and splash erosion rate in rangeland (r=0.767, p=0.001) and significance positive correlation between K-USLE and splash erosion rate in agriculture (r=0.00, p=0.758).

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Arbuscular mycorrhizae (AM) and Plant Growth Promoting Rhizobacteria (PGPR) associations are integral and functioning parts of plant roots. These associations have a basic role in root uptake efficiency as well as improvement of plant growth in degraded environments including heavy metals contaminated soils. This study was conducted to evaluate the effects of heavy metal-resistant soil microbe's inoculation on bio-availability of Pb and Cd in soil, plant growth as well as metal uptake by Millet (Pennisetum glaucum), Couch grass (Triticum repens) and wild alfalfa (Medicago sativa). A soil sample was treated by different levels of Pb and Cd (soil 1). Native microbial inoculums were obtained from alfalfa rhizosphere soils adjacent to Pb and Cd mines in Zanjan region (soil 2), then added with weight ratio of 1:5 (w/w) to soil 1. Host plants including millet, couch grass, and alfalfa were grown in pots and kept in greenhouse conditions. At the end of growing period, shoot dry matter and Pb and Cd concentrations in plant and soil were measured. Results indicated that plants yield and Pb uptake were significantly higher in non-inoculated treatments (p ≤ 0.05). However, Cd uptake by plants was greater in inoculated treatments (p ≤ 0.05). Couch grass showed the most accumulation potential of Cd and Pb among the studied plants.

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Soil erodibility and gully erosion and their expansion occur under geological formation and soil characteristics. This study aims to find the rate of soil and formation effects on gully erosion in Seifabad watershed. To that end, aerial and field work were used together to determine the rate & expansion of 17 gullies in 12 years' period from 1997 to 2009. The soils were sampled for each gully in 50% interval distance with 0-30 cm horizontal surfaces and >30 cm depth. Some factors were estimated from the soil such as EC, PH, Silt, Clay, Sand & limeston percentages. Statistical analysis was done using SPSS 14 through non-parametric tests such as Kruskal-Wallis & Mann-Whitney. Spearman coefficient was used to investigate the relation between volume of gully & litological factors. The results showed a positive correlation at 1% level for the PH with the gully erodibility in surface soil, but for the depth of soil this relation belonged to the silt percentage, and sand showed a negative relation at 5%level with the volume of the gully sediments. Finally, there was no statistical relationship between geological formation and the sediment yield in gullies.