Showing 15 results for Interaction
A. Mirlohi, M.a. Hajabassi, S.j. Razavi, E. Ghanaati,
Volume 5, Issue 1 (4-2001)
Abstract
Soil loss due to erosion is a common problem in most parts of Iran. Reduced soil organic matter and lack of proper agricultural management have intensified the problem in recent years. Conservation tillage systems are becoming more widely used in corn production in other parts of the world because of soil losses due to wind and water erosion and energy inputs. Changes in tillage methods, however, create different environments for the germination, development and maturation of corn plants. Most corn hybrids have been selected and developed under conventional tillage systems but these hybrids mayor may not be well adapted to both systems. This study aims to evaluate the performance of five locally grown corn hybrids under zero and conventional tillage methods. The experiment was conducted for 2 years on a plot of land specified for this study. Experimental design was a split plot with randomized complete block arrangement and four replications.
Seedling and juvenile plant growth were not affected by tillage method and were similar for all hybrids. Plant dry matter was affected significantly by the cropping system and was lower in no-till method. Plant leaf area index and stem diameter reduced significantly in the no-till system. Reduction was greater in the second year of the experiment. Also grain yields were significantly different among years, tillage method and plant genotypes. Yield reduction was highest in the second year of the experiment under no-till cropping system. There was no interaction between tillage method and corn genotypes, indicating that, usually genotypes perform similarly with regard to grain yield under both tillage methods. The results suggest that corn production under no-till system in Isfahan is probably associated with yield reduction.
A. Kheiri, A. Borhani, S. M. Okhovvat, H. Eshtiaghi,
Volume 7, Issue 3 (10-2003)
Abstract
In an etiological study on stunted, nursery grown maple seedlings, a species of root-lesion nematode (Pratylenchus vulnus) and two species of fusarium (Fusarium oxysporum and F. solani) were isolated from the infected roots. Interactions between the nematode and the two fungi in a complete randomized design with six treatments and four replications were carried out under greenhouse conditions. Nematodes were surface sterilized and reared on sterilized carrot discs. Then the maple seedlings at two-leaf stage were inoculated with a population density of 40 nematodes/100 gr soil in pots. The results indicated singnificant differences between the treatments. Seven months after inoculation, the treatments with nematode alone showed a high mortality rate of about 75% along with a severe increase in population up to about 11.2 and 1266 nematodes/gr of soil and roots, respectively. In treatments with nematode and each of the two-fungus species, the deleterious effects of fungi on nematodes were observed through decrease of nematode population. It was also shown that F. oxysporum was more effective than F. solani in nematode control.
M. Shahmohamadi, H. Dehghani, A. Yousefi,
Volume 9, Issue 1 (4-2005)
Abstract
To determine yield stability and to evaluate genotype interaction with environment interaction, 18 genotype of barley (Hordeum vulgare L.) and a control group were evaluated in a randomized complete block design with 4 replications in 3 successive years (1997-2000) at 10 research stations. Simple and combined analysis of variance revealed significant genetic differences between yield genotypes for grain yield. The results of combined analysis of variance indicated that genotypic and genotype were significant through interaction with environment. Therefore, different stability parameters including, environmental variance (S2i), environmental coefficient of variation (C.Vi), mean of variance of interaction (θi), interaction variance (θi), equivalence ( W2i), stability variance (σ2i), linear regression coefficient (bi, βi), mean of squares of deviation from regression (S2 di) and years within location MS for a genotype, averaging over all locations (MSy/l) were determined. Based on all the stability parameters, genotype 18 was known as the most stable one and genotypes 17 and 11 ranked lower. Genotype 5 with the highest yield was known to be the most adaptable one at fertile environments and is recommended for these locations. In addition, genotype 9 with good yield and low yield variance (1.58) and regression coefficient of less than 1 is suggested for unfertile locations.
G. Mohammadinejad, A. M. Rezai,
Volume 9, Issue 2 (7-2005)
Abstract
In this study, the an AMMI analysis (additive the main effects and the multiplicative interaction effects) was used to evaluate the yield stability of nine oats genotypes (4 Canadian cultivars and 5 Turkish breeding lines) and Makoi barley (as ckeck) in the 6 environments (3 dates of planting of Oct.12, Oct.31 and Nov.21 and 3 sowing densities of 300, 375 and 450 seeds/m2). The experiment was conducted at the Research Farm of Isfahan University of Technology in 2001. For each environments, a randomized complete block design with the 3 replications was used. According to the results obtained, the main effects of genotypes, environment and genotype X environment interaction effects were statistically significant (p<0.0 1) and 70% of sum of squares was explained by the first two interaction principal components (IPCI). Biplots of genotypic and environmental components of the first and second interaction principal components and the mean yields of the genotypes and environments, pattern analysis of the two significant and also stability statistics of AMMI model (EV2 & SIPC2) revealed that Boyer and Line No. 28 were the most stable genotypes. Boyer had the lowest IPC1 and Pacer and Lines No.2 and 17 were the least stable genotypes with specific adaptation to sowing density of 300 seed/m2. Lines No.32 and 28 indicated the specific adaptions to first planting date (Oct.12) Makoi and Pacer had the specific adaptation to second and third planting date and the second sowing density.
R. Karimizadeh, H. Dehghani, Z. Dehghanpour,
Volume 10, Issue 3 (10-2006)
Abstract
To facilitate the interpretation of data from a genotype by environment experiment (GE), a cluster method is proposed to group genotypics according to their response to the environments especially when the GE interaction is large. The interaction structure of two-way classification data often can be identified if the data stratified into homogeneous subsets. In this paper four GE interaction cluster methods are proposed for this purpose. The stability of the 10 maize hybrids including 9 hybrids that were the best hybrids in yield trials and KSC 301 (check hybrid) were evaluated for 2 years in 4 locations of Iran. The randomized complete block design with 4 replications was conducted for each environment with different layouts. Simple analysis of variance revealed significant genetic differences between hybrids for grain yield. The results of combined analysis of variance indicated that genotype × year, genotype × location, and genotype × year × location interaction effects were significant (P < 0.01). Results also showed that models 1 and 3 and models 2 and 4 had the same responses. Hybrids 8 (K1263/1 × KE8212/12) with high yield stability in both models 1 and 3 were in one group and other hybrids were in another group. In models 2 and 4 results led to 3 groups: Group1 included hybrids 3, 7 and 9 that were very stable and had high yield group 2 included hybrid 1 alone that had medium stability and yield and group 3 included other hybrids that had low stability and yield.
G. Mohammadi Nejad, A. M. Rezai,
Volume 11, Issue 1 (4-2007)
Abstract
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.
H. Zali, S.h. Sabaghpour, E. Farshadfar, P. Pezeshkpour, M. Safikhani, R. Sarparast, A. Hashem Beygi,
Volume 11, Issue 42 (1-2008)
Abstract
Presence of genotype × environment interaction necessitates evaluation of genotypes in a wide range of environments to find desirable genotypes. This study was carried out to determine the stability and adaptability of grain yield of 17 chickpea genotypes, in RCBD with four replications at Kermanshah, Lorestan, Ilam, Gachsaran and Gorgan Research Stations during two seasons (2003-2004). The genotype × environment interaction effect analyzed using the additive main effects and multiplicative interaction (AMMI) statistical model was significant at 1% level of probability. The sum of squares of G × E interaction was partitioned by AMMI model into four significant interaction principal component axes (IPCA). The first four principal component axes (IPCA 1, 2, 3 and 4) cumulatively contributed to 94% of total genotype by environment interaction. A biplot generated using genotypic and environmental scores of the first two AMMI components also showed that genotypes FLIP 97- 79, X95TH1 and FLIP 97- 114 were selected as stable genotypes, among which the genotype FLIP 97- 114 was outstanding for high yield stability.
N. Sahebani , J. Zad , A. Sharifi-Tehrani , A. Kheiri ,
Volume 12, Issue 43 (4-2008)
Abstract
Polyphenol oxidase (PPO) activities were measured spectrophotometrically in tomato(Roma VF: resistant to Fusarium oxysporum f.sp. lycopersici and susceptible to Meloidogyne javanica) roots inoculated with nematode and fungi in four biological life stages of nematode. PPO specific activity showed a significant decrease in treatments (nematode + fungi) as compared with control plants. Results showed that nematode is able to change or suppress induction of this enzyme in spite of fungal induction. Nematode in all biological stages suppressed the induction of PPO activity in tomato roots but in young adult formation stage the suppression was higher than other life stages including giant cell formation, egg-laying and penetration. Native polyacrylamide gel revealed the presence of five isozymes of PPO with Rm values of 0.26, 0.31, 0.44, 0.50 and 0.63. Isoforms with Rm values of 0.26, 0.44, 0.50 and 0.53 showed significant changes in nematode + fungus inoculated tomato plants compared to plants inoculated with fungus alone. Based on the results obtained in this study, nematode infection resulted in suppression of tomato defenses against the fungi (as secondary pathogen) and intensified the fungal disease. Five PPO isoforms with Rm values of 0.26, 0.31, 0.44, 0.50 and 0.63 were shown in native polyacrylamide gel among which the isoform with Rm value of 0.31 had a thicker band in tomato plants inoculated with nematode or fungus alone. Two isoforms with Rm values of 0.44 and 0.53 in nematode-inoculated plants were similar to the corresponding bands in the healthy control. Isoforms with Rm values of 0.26, 0.44, 0.50 and 0.53 in nematode-fungus-inoculated tomato plants showed significant changes compared to plants inoculated with the fungus alone. Nematode infection of root tissue caused suppression of PPO specific activity and induced changes in PPO isoforms with Rm values of 0.26, 0.44, 0.50 and 0.63 more significantly than isoform 0.31.
N. Sahebani, N. Hadavi,
Volume 12, Issue 43 (4-2008)
Abstract
This research was conducted to study the effect of nematode (Meloidogyne javanica) on severity of tomato Fusarium wilt (Fusarium oxysporum f.sp. lycopersici race 1) and changes in Phenylalanine ammonia lyase (PAL) activity in split-root assays to show the possibility of systemic induced susceptibility caused by nematode to the fungus by local nematode infection. The results showed that the activity of nematode in one part of root confered susceptibility to Fusarium wilt in other part of the plant root and subsequently disease symptoms increased significantly in comparison to the control (without nematode inoculation). PAL specific activity showed a significant decrease in one half of split-root inoculated with fungus when the other half was inoculated with nematode as compared with the control (without nematode inoculation). Based on the results obtained in this study, nematode infection in one part of tomato plant root resulted in suppression of tomato defenses in all parts of the root, reduced tolerance or resistance to the fungus (as secondary pathogen) and intensified the fungal disease.
S Kamli, O Alishah, N Babaian,
Volume 13, Issue 48 (7-2009)
Abstract
To assess adaptability and stability of seed cotton yield in promising cotton genotypes, eight cultivars of cotton (Gukorova, Nazeli–84, Khordad, No: 200, Crema, Tabladila, Beli Izovar and Sepid), along with two controls (Sahel and Varamin), were studied in a completely randomized block design (RCBD) with four replications in six regions of Golestan and Mazandaran provinces in two successive years (2005 & 2006). Combined analysis of variance was done and means comparison of yield was conducted based on Duncan's multiple range test. Sepid, Beli Izovar, Varamin and Khordad varieties were superior for yield, earliness, boll weight and boll number, respectively. The result of combined variance analysis showed that, there are significant differences between genotypes and genotype × environment (G.E) interaction effect. Because of significant G.E interaction effect univariete stability parametric and non-parametric stability methods were used to determine genotype stability. The results of varied methods were different. The 43200 and Sepid cotton cultivars had a specific adaptation and were suitable cultivar for fertile lands in north of country, because of good reaction to production high yield. In contrast, Sahel cultivar with lowest yield had broad stability with non-fertile regions. Overall, three genotypes (Khordad, Tabladila and Gukorova) were determined with suitable stability and moderate yield (general stability) for most locations in north of country.
R Karimizade, B Vaezi, T Hoseyn Por, A Mehraban, H Ghojagh,
Volume 13, Issue 48 (7-2009)
Abstract
Multi-environment trial data are required to obtain stability performance parameters as selection tools for effective cultivar evaluation. The interrelationship among several stability parameters and their associations with mean yield, along with the repeatability of these parameters in consecutive years was the objective of this study. Barley yield data of 18 cultivars, proprietary of Dryland Agricultural Research Institute, evaluated in 12 locations over 2005-2007 in three locations of Iran was used for the combined analysis of variance in three datasets. I: Across locations in a single evaluation year (dataset A), II: Across locations in each of two single evaluation year (dataset B), III: Across all locations in three years (dataset C). For each dataset, cultivar phenotypic variance and other statistics were appropriately partitioned in its components. The interrelationship among the parameters and their associations with mean yield based on Spearman rank correlation was studied in each of the three single evaluation years (dataset A). Rank correlation coefficients were also used as estimates of the repeatability of these stability parameters across two year combinations (dataset B). The parameters 2 σi Shukla and 2 Wi were consistently highly correlated with each other but not with mean yield in all single and pair evaluation years. The parameters bi , 2 Si and CV were consistently highly correlated with each other but not with mean yield in all single and pair evaluation years. Result showed that Shukla variance, Wricke ecovalence, SIPC1 and ASV AMMI stability statistics have high repeatability. Thus it is suggested that more stability statistics especially nonparametric methods be used for determination of repeatability methods.
M. Mirmohammad Sadeghi, B. Ebrahimi, M. Pasandi,
Volume 22, Issue 2 (9-2018)
Abstract
Depletion and consequently reduction in groundwater storage results in numerous harmful environmental effects such as reduction in yields of wells, land subsidence, lowering of water quality and also reduction in storage of surface water bodies having hydraulic relation with aquifers. In this research, groundwater depletion in the Najafabad subcatchment aquifer located in the GavKhouni basin, Isfahan province was evaluated. These studies indicate groundwater depletion and deterioration of the aquifer water quality during the recent years. Zayandehroud River had been effluent and it has recently converted to influent and dominantly recharges the aquifer. The groundwater depletion in this region has been due to wells overpumping and it does not comply with the uniform rainfall variations in recent years. According to the shaly aquifer bedrock, the groundwater depletion cannot be due to leakage through the bedrock. Moreover, the groundwater quality has been deteriorated in all parts of the aquifer, especially in the regional drawdown cones resulted from recently groundwater overexploitation by deep wells. The river leakage to the aquifer is predicted to be persistent and increasing according to results of the research and it is necessary to limit the groundwater extraction and change the average surface water inflow to the area to mid 1370s condition.
E. Sadeghi, F. Raiesi, A. Hossienpur,
Volume 23, Issue 2 (9-2019)
Abstract
Abiotic stresses such as salinity and contamination individually have a negative effect on the soil enzyme activities, whereas addition of organic matter to soil can alleviate the negative impacts of stresses on the enzyme activity. However, the combined effects of these stresses (multiple stresses) on soil biochemical conditions and the role of organic matter addition in these interactions are largely unknown. The objective of this research was to explore the interaction effect of NaCl salinity and cadmium (Cd)-pollution on the activities of catalase, alkaline phosphatase, arylsulfatase and fluorescein diacetate hydrolysis in a Cd-contaminated calcareous soil treated with alfalfa residue over 3 months of incubation. A factorial experiment with 2 levels of Cd, 3 levels of salinity and 2 plant residue treatments was conducted using a completely randomized design with 4 replications. The results indicated that salinity increased the Cd availability in both uncontaminated and contaminated soils and reduced the soil enzymatic activity. Nevertheless, addition of alfalfa residue reduced the detrimental effects of salinity and Cd-pollution on the soil enzyme activities. This indicated that in saline Cd-contaminated soils with low organic matter, adding plant residues could lower the concentration of available Cd and the effect of soil salinity with a concomitant increase of enzyme activities. So, this study showed that the joint effect of NaCl salt and Cd on enzyme activity was mostly synergistic in plant residue-untreated soils, but it was antagonistic in the plant residue-treated soils.
E. Mokallaf Sarband, S. Alimohammadi, Sh. Araghinejad, K. Ebrahimi,
Volume 24, Issue 4 (2-2021)
Abstract
In determining the allocation of water resources, the probable conditions of water resources and water demands are considered as the water allocation scenarios in the basin scale. Then, these scenarios are evaluated in the context of integrated water resources management and from the perspective of sustainable development indicators. The best scenario is selected in order to determine the water allocations. In these evaluations, there are spatial distributions and their interactions are simultaneously the key charaterictics in the decision matrix. These features are not often considered in the evaluation process. In the present study, distributed indicators and simple and integrated multi-criteria evaluation models, including ANP and CP methods, were used to evaluate the water allocation scenarios in the Aras Basin. The results showed that modeling of the spatial distribution and interactions of water allocation impacts was not possible through any of the simple multi-criteria evaluation methods. Simplifying and discarding one or two key features in the evaluation process can lead to significant uncertainties on rankings with a Spearman coefficient of -0.1. By implementing the integrated spatial decision-making approach and applying two features simultaneously, the fourth scenario was ranked first. The proposed approach was compared with the individual models, showing more accurate, with the correlation coefficients of 0.5, 0.6 and 0.7.
Sh. Nasiri, H. Ansari, A.n. Ziaei,
Volume 25, Issue 3 (12-2021)
Abstract
Reducing surface water resources and successive droughts and consequently excessive use of groundwater resources, especially for agricultural purposes, have caused irreparable damage to the natural resources of the country. In the meantime, knowing the status of the water balance of the plain can help to effective management of water resources in the region. Samalqan plain is located in a semi-arid climate in North Khorasan Province. Since the surface water resources for water supply are not very reliable, so, the main source of water supply in the region is
well. Due to the existence of rivers in the plain, the low thickness of the alluvium, groundwater level fluctuations, and the high uncertainty in the calculation of hydrodynamic coefficients, the need for careful hydrogeological studies and determining the role of each parameter affecting groundwater is necessary. This study was conducted to simulate the Samalqan aquifer and analysis of water balance for the years 2003 to 2013 using the MODFLOW model. To identify the groundwater recharge rate, this component was estimated by the SWAT model. Calibration and validation of the model with an error of 1.1% and 1.2%, respectively, indicated that an appropriate estimation between the simulated and observed heads. Assessment of the groundwater hydrograph in the observation wells showed that the groundwater level in most places has many monthly and seasonal fluctuations. After drawing the potential lines of the plain, the inputs and outputs were identified, and using the reserve volume changes, the water balance was determined. The results showed that the water balance of the plain was negative and the reservoir deficit was estimated at 9.14 million cubic meters. Therefore, this model can be used to predict the future situation of aquifer and the management of
water resources in the region.
