جستجوی مقالات مرتبط با کلیدواژه "path analysis" در نشریات گروه "باغبانی"

Cantaloupe is one of the most important vegetable crops in Iran. In recent years, due to some problems, such as low sweetness and fruit yield, plant death diseases, and the indiscriminate introduction of foreign commercial hybrid cultivars, the genetic resources of this product have been severely eroded. Therefore, in this research the crossing of important local cultivars such as Saveh and Niagara with the commercial and selected F1 cultivar Galia was considered to combine the best traits and select the best genotypes of the F2 generation by pedigree selection method and continuity of generations. This experiment was carried out in the Faculty of Agricultural Technology (Aboureyhan Campus) University of Tehran research farm. The selection of the best genotypes was done in three stages (natural screening in the field for disease, virus, and mite resistance, evaluation based on qualitative traits in the laboratory, and final selection of genotypes based on the results obtained from multivariate analysis of quantitative traits). The results showed that in Niagara × Gallia (NGF2) population, general heritability was high for all the evaluated traits except the fruit shape index. In the Saveh × Gallia (SGF2) population flesh thickness, soluble solids and fruit harvest date had the highest heritability. The results showed that the traits included in the stepwise regression model accounted for 90.3 and 80.3 percent of the total changes related to fruit weight in NGF2 and SGF2 populations, respectively. Based on the principal component analysis, in NGF2 and SGF2 populations, two principal components explained 71.88 and 71.31% of the data variance, respectively. Based on the results of the bi-plot analysis, 30 NGF2 and 53 SGF2 genotypes were selected, and cultivated in order to continue generations and reach pure parental lines in the F3 generation.

In order to evaluate of agronomical traits and fruit yield in 23 breeding hybrid cultivars of greenhouse cucumber, and determine the relationship between these traits, a randomized complete block design with three replications was performed in the research greenhouse of Islamic Azad University, Isfahan (Khorasgan) Branch in 2014-15. Data was collected for these traits: total fruit yield, total fruit number, number and fruit yield on three periods, plant height, length and width of leaf, length and diameter of fruit, days to flowering and fruiting and the first flower node. Coefficient of correlations showed that total number of fruit and fruit diameter had significant and positive correlation with fruit yield. Path analysis revealed that fruit number had the highest direct and positive effect on fruit yield. Therefore this trait could be used as selection criterion for selecting genotypes with high fruit yield. Step wise regression showed that total fruit yield and fruit yield on mid fruit production period explained 96.30 percentage of fruit yield variation. On the other hand, total fruit yield and fruit number on final fruit production period explained the highest amount of total fruit number variation.

Ajowan (Trachyspermum copticum L.), belonging to the Apiaceae family, is remarked as an important pharmaceutical and economical product. In order to determine the most important traits affecting grain yield, a split plot experiment was conducted in two conditions of irrigation (normal and drought stress) as the main factor and 36 ecotypes of ajowan, belonging to nine different provinces of Iran, as a sub plot based on a randomized complete block design with two replications in 2015 and 2016 crop year in Kerman. The results of linear multiple regression analysis with stepwise method showed that in drought stress condition, number of umbrellas per plant, number of seeds per umbrella and essential oil yield, and in normal irrigation conditions, biological yield, 1000-seed weight and seed number per umbrella had the highest effect on grain yield, explaining 87% and 99% of the changes, respectively. Based on the results of path analysis, traits including number of umbels per plant under stress conditions and biological yield under normal conditions had the most direct effect on the grain yield and were recognized as the most important components of the grain yield. Therefore, these traits can be considered as main appropriate criteria for facilitating the indirect selection process and evaluating the seed yield potential in ajowan breeding programs.

This experiment was conducted to investigate the identify traits explaining yield variation, recognize relationships between traits and classify accessions in spring rapeseed, at Dezful, Khozestan Province Iran,  in the agricultural year in 2015–2016. A randomized complete block design with four replications was used. The results of stepwise regression analysis revealed that 1000-grain weight, number of pods per plant, HI and days to maturity significantly had more important effects respectively on seed yield. The results of path analysis indicated that the number of grain per pod and 1000-grain weight had the largest direct effects on the grain yield. According to the results of the principal component analysis, PC1 was moderately correlated with number of seeds per pod, 1000-seed weight and seed yield. PC2 was moderately correlated with days to flowering, days to maturity and plant height. The results of factor analysis exhibited two factors including sink factor (number of seeds per pod, 1000-seed weight and seed yield) and fixed capital factor (phonological traits). It seems that its seams possible to use their traits as a selection criteria in breeding programs for improve seed yield of spring rapeseed cultivars. using WARD method cluster analysis revealed five groups and there was highest genetic distance between 1 and 5 groups, thus predict that hybridization of between 1 and 5 groups could provide best hybrids and supply a desirable genetic diversity in segregated generations for breeding programs.

Assessment of genetic diversity and identification of important traits in a population is a basic pre-requisite for the choice of parents in breeding programme. Therefore, in order to study of genetic diversity in some Iranian onion morphotypes and using its results in breeding programs, seeds of 23 morphotypes were planted using a randomized complete block design with three replications in East Azarbaijan Agricultural and Natural Resources Research and Education Center in 2010 and 2011. Combined analysis of variance indicated that there were great diversity among morphotypes for the studied traits. Cluster analysis, using ward’s method, grouped the morphotypes into three groups. Grouping based on morphological traits showed relative correspondence between genetic diversity and geographical pattern. In principal component analysis, the first three principal components accounted 79.70% of the total phenotypic variation. Morphotypes with higher values for the first component, would have higher yield and the morphotypes with lower values for the second component, would have higher quality. Morphotypes with higher values for the third component also would have higher dry matter percentage. Path analysis showed that bulb length had the largest significant positive direct effect (0.6) on bulb mean weight. Direct effect of bulb diameter was also significaint on bulb mean weight (0.22). The highest indirect effect of leaf length via bulb length was 0.55. Therefore, selection of plants with higher leaf length and higher bulb length and diameter could be more useful in breeding for increased yield in these population. ‘Qirmiz Rey-2’ and  and ‘Gogan-2 pomegranate shaped qirmiz Azarshahr’ were superior morphotypes of this experiment. Due to the low percentage of dry matter, the morphotypes under study are not suitable for processing industry but suitable for fresh-market.

Despite the importance of the German chamomile (Matricaria chamomilla L.), as one of the most widely used medicinal plants in the world, there is little information about the genetic variation within and between its populations in Iran. This study was conducted to investigate the genetic diversity of 15 chamomile populations based on morphological characteristics in a randomized complete block design with three replications. Height, flower diameter, receptacle diameter, fresh flower weight, dry flower weight, wet biomass, dry biomass, flowering index, essential oil percentage and Chamazulene percentage were analyzed. The populations had a significant difference for all traits (P≤0.01). The phenotypic and genotypic variation was obtained to be more than 60% for dry weight, dry mass and Chamazulene content. Significant values were recorded for the heritability of the traits including percentage of kemazolen (94.04), the wet biomass (93.93), plant height (90.59), flower diameter (86.52), dry flower weight (84.15), and dry biomass (83.08). The highest and lowest yield (kg/ha) were related to Hamedan (9700) and Eurea (753.33) populations, respectively. The highest percentage of Chamazulene and essential oil content were obtained from Dehroud (14.10) and Jam-o-Riz (0.61), respectively. The flower diameter had the highest correlation (0.62) with the percentage of essential oil. Regression analysis for essential oil percentage as the dependent variable was performed and four traits including flower diameter, height, and fresh weight of flower were introduced into the model, explaining 59% of the variation. In the path analysis for essential oil percentage as the dependent variable, the highest direct effect was related to the fresh weight of flower (1.09) and the highest indirect effect was related to the fresh weight of flower (1.06). The cluster analysis grouped the populations into three groups that did not follow geographical distribution.

The usefulness of any corrective program is determined by the relationship between the grain yield and the factors affecting it. For this purpose, 25 winter wheat cultivars were planted and evaluated in a randomized complete block design with three replications in a field experiment at the Faculty of Agriculture, Karaj Azad University, Karaj, Iran under two irrigation conditions (normal irrigation and irrigation after the spike stage). 17 traits were measured and evaluated. Simple correlation coefficients of traits indicated a positive and significant correlation between grain yield and days to flowering, biological yield and harvest index in normal conditions, and traits related to rooting, biological yield, harvest index and peduncle outflow length in drought stress conditions. The results of stepwise regression confirmed the relation between grain yield and biological yield., path analysis was performed for the traits introduced in the stepwise regression model and in both normal and stress conditions the most direct effect on grain yield had belonged to biological yield.

In order to investigate relationship between yield and its components in bread wheat, tested during 2011-2012 were conducted in Agricultural Research Station of Gonbadin randomized complete block design with three replications whit 10 bread wheat genotype (Morvarid, N-87-4, N-87-9, N-86-6, N-86-8, N-80-19, N-86-5, N-85-5, Kohdasht, Line 17). In this experiment, were measured 7 morphological traits. Analysis of variance genotypes for all traits was significant at 1% probability level. N-85-5 and Line 17 genotypes produced the highest and the lowest grain yield, respectively. Among all tested traits, the number of fertile spike had the highest correlation (0.999 **) with grain yield. Using stepwise regression, the number of fertile spikes entered the model as an effective attribute, justifying 99.8 percent of the data variation. In order to find the causal relationships, the path analysis was performed for grain yield The direct effect on the grain yield was related to the number of fertile spike traits. The results of cluster analysis by ward method showed that the studied cultivars were classified in two groups and the second group in terms of grain yield was the most (397.66). According to the results, can be said that N-85-5 genotype had the highest grain yield and trait number of fertile spike was identified as an effective trait for increasing grain yield.

This study carried out to examine the relationships between effective traits and yield in 12 sunflower varieties. A randomized complete block design with three replications was used. Results of simple correlation showed that seed width, seed diameter, seed length and hundred grain weight correlations with kernel yield were significant at the 1 percent probability level. In stepwise regression analysis, seed width was the first trait entered in the model and explained approximately 67 percent of the total yield changes. Seed length and diameter of stem entered to the model after the seed width trait and a total of 88 percent total yield variation was explained. The characters entered into the regression model were used for path analysis to identify direct and indirect effects of traits on grain yield and their proportion of effect. The results showed that seed width, seed length and stem diameter had the most direct and positive effect on the yield, respectively. In this study, three independent factors encompassed 75 percent of the total variation. The first factor with 35.5 percent of the variance was mostly influenced by grain yield, plant height, leaf length and leaf width which was named the grain yield. The second factor with 26 percent of the total variation was mostly represented seed length and seed weight and named seed features. The third factor was highly affected by stem diameter, seed diameter and seed width with 13.4 percent of variance explained and was named the plant diameter.

The most important cereal Barley and due to the high compatibility of different environments screw. In order to evaluate the agronomic morphophysiological trait of barley, 103 families F3 of a cross Becher × Kavir in randomized complete block design with three replications at the Agricultural Research Station of Gonbad kavus was cultured.The most important traits measured, grain yield, number of spike, number of grains per spike, biological yield, total weight and length spike Analysis of variance showed that all traits except plant height was a positive and significant. Results the comparison average showed the highest and least grain yield was related 87(8572.8) and 6(1946.3) families. The highest correlation coefficient was related to grain yield and biological yield (r=0.68**). Cluster analysis divided families into four groups that it of 55 families was the largest group. The highest grain yield (7187/05) and the total number of spikes (639/56) belong to the second group, as well as for grain weight (29/50) and number of grains per spike (44/08) highest the amount was in the first group. Stepwise regression analysis biological yield the first adjective, grain yield model and 0.470 of the changes to be justified. Path analysis showed that biological yield (1.016) highest strong and direct impact on yield. Identify the attributes and the relationship between them it is necessary to determine the selection criteria and can be effective in the selection of high yielding genotypes.

In order to compare barley double haploid lines from agricultural and morphologic characteristic aspects and recognition of probable lines, 45 double haploid lines of grain were experimented in the form of random complete blocks with 3 frequencies under two normal irrigation and low water stress conditions at mahabad Agricultural researches station from 2011-2012. Results obtained from combined variance analysis of two experience case miles from all examined characteristics aspects, expect, for bush height. In regression analysis with step by step method. Grain performance under normal irrigation conditions from aspects such as number of grains in spike, straw performance, and each grain weight entered in final model that under normal irrigation and low water stress condition, has three performance such as straw, grain and the number of grain in spike as influence variable to grain performance entered to model. So the performance in two conditions showed that has the most positive and direct effect to grain performance.

Ten barley cultivars base a Randomized Complete Block design with three replications in normal and drought conditions investigated in 2014-15. Grain yield, harvest index, plant height spike length, spike weight, awn length, thousand grain weight, stem diameter, seed length, seed diameter, peduncle length, day to heading and day to physiological maturity were measured. Results of variance analysis showed that in normal conditions of moisture between the varieties in terms of grain yield, harvest index, spike length, spike weight, awn length, stem diameter, seed length, seed diameter, peduncle length, days to heading and days to physiological maturity and In stress condition the varieties in grain yield, harvest index, plant height, spike length, spike weight, awn length, stem diameter, seed length, seed length and peduncle length showed significant difference. Path analysis indicated that in normal conditions, direct effect, harvest index, plant height and peduncle length on yield is positive and high. in stress condition, harvest index, positive and direct effect and days to heading negative and direct effect on grain yield were that positive effects of increased correlation of with grain yield and, negative effects of reduce the correlation between grain yield and selected attributes will be followed by regression. Results from this study showed that Characteristics such as harvest index, plant height, peduncle length, awn length, and thousand grain can be as indicators for selecting cultivars with high yield in stress and non-stress condition can be recommended.

In order to study of genetic variation in cultivars and landraces of chickpea a trial consisted of 26 genotypes of chickpea(ciceraaritinum.l) for one year(1393) in framework of completely randomized bloak design with 3 replcation were evaluated at the experimental field soil and water Koohin.The results of ANOVA showed that there were significant differences among accessions for the studied traits expected for biological yield which reveald genetic variation for different traits.The results of comparing the mean of the Genotypes related to the trait of yield (kg/hac)", showed that genotype number 66 (3101ardabili) had the highest function traitand genotype 82 (3240Varamin) had the lowest amont yield respectively. According to the results of phenotypic correlations,trait yield per plant and total yield with the studied ofen traits had significant differences.Stepwise regression for selection of traits related to yield of the seed indicated that weight pod, plant height, number of pods 2 twins explained 87 percent of to tal varation. The result of path analysis indicated that plant yield and biological yield had the greatest direct effect on seed yield respectively.. The results of cluster analysis with Ward's method genotypes were grouped in five clusters.that the genotypes of 65 (3099ardabili) and 66 (3101ardabili) as the best genotypes yielded in the five groups and genotypes of 15 (Kermanshahi) as the least the yielded genotypes in the tree grouping. The results of the analysis in to the principal components showed that there were five main components selected that in total, they explained %87 of total variation, respectively.Factor analysis showed that five factors: yield components, seed characteristics, plant morphology, precocity and plant height that explained 87% of total variation.

In order to study the morphological characteristics affecting yield of Echium amoenum under different nutritional treatments and different plant densities, a factorial experiment based on RCBD design with three replications was conducted at Agricultural Research Station, Ferdowsi University of Mashhad, Iran in 2011-2013 growing seasons. The experimental treatments were all combination of three plant densities (10, 5 and 3 plant.m-2) and five different types of organic and chemical fertilizers (compost, vermicompost, cow manure, chemical fertilizer and control). Results showed that organic fertilizers increased flower yield compared to control treatment. The flower yield of compost, vermicompost and cow manure treatments were 25, 28, and 27 percent more than control, respectively. Results of multivariate regression showed that variables of plant height, shoot dry weight, and number of flower per plant were the main factors affecting yield of flower; meanwhile, the relative contribution of shoot dry weight was approximately 16 and 25 percent more than plant height and number of flowers per plant, respectively. Based on the results of path analysis, shoot dry weight per plant had indirect effect on yield flower in different ways, but most of its indirect effect was imposed through plant height on the yield flower.

To determine the relationship between yield and components of it and identify the effective traits on yield, 97 tomato landraces from West Azarbaijan in Iran (83 landraces) and Iğdır in Turkey (14 landraces) along with three commercial cultivars were studied using an alpha lattice design with two replications. The experiment was carried out at the Agriculture and Natural Resources Research Center of West Azerbaijan during two years (2012-2013).Combined analysis of variance indicated significant variation among cultivars for all the experimental characters. Correlation analysis revealed significant positive correlation between yield and length and width of cotyledon and true leaves, number of days to fruit maturity, fruit weight, length of fruit, diameter of fruit and pericarp thickness while significant negative correlation was observed between yield and number of flowers per inflorescence, fruit set per cluster, number of fruits per plant, number of days to 50 percent of fruit maturity, total soluble solids (TSS) and acidity. In stepwise regression analysis fruit length, TSS and percentage of fruit set per cluster were entered to the model, respectively. These characters explained 43 percent of yield variation. Path analysis showed that fruit length, leaf width, fruit weight and pericarp thickness have the most positive direct effect on yield. Thus, these traits could be used as selection criteria in tomato breeding programs for yield improvement.

To identify the high yielding lines with optimal characteristics, 40 recombinant inbred lines derived from a cross between ‘Norstar’ (winter wheat) and ‘Zagros’ (spring wheat) cultivars were examined using a randomized complete block design with three replications in 2014 at the Research Station of Faculty of Agriculture, University of Tabriz, Iran. The measured characters consisted of peduncle weight, penultimate weight, spike weight, kernels per spikes, biomass, grain yield, 1000 kernel weight, plant height, peduncle length, penultimate length, spike length, harvest index, flag leaf area and straw yield. Significant differences were observed among lines for all the studied traits, except spike weight, flag leaf area and straw yield. Higher genetic diversity was observed among inbred lines with respect to kernels per spike, number of spikes, biomass and straw yield. Peduncle weight, penultimate weight, kernels per spike, number of spikes and 1000 kernel weight had high heritability. The highest genetic gain was obtained for peduncle weight, penultimate weight and kernels per spike. Based on trait means, lines NO 93, 28, 296 and 31 were identified as superior genotypes. Correlation, stepwise regression and path analysis revealed that kernels per spike and number of spikes were more effective components on grain yield. The analyses were carried out using WARD algorithm and standardized data. Cluster analysis was performed based on all traits and lines were classified into four groups. In factor analysis, four first factors explained about 82 percent of total variations.

This research was designed to identify garlic (Allium sativum L.) bolting clones and determining the relationship between their morphological traits and bolting capacity by using statistical methods of analysis of variance, comparison of means, correlation coefficients, factor analysis, stepwise regression, path analysis and cluster analysis. Traits including flowering ability, number, length and width of leaf, position of the longest leaf, length and diameter of pseudostem, weight of bulb and clove, number of cloves in bulb, percent of clove dry matter and yield were investigated in 30 Iranian garlic clones. Results of analysis of variance showed significant difference in all studied traits of clones. Coefficients of correlation test showed that there was significant negative correlation between bolting and number, length and width of leaf, position of the longest leaf, diameter of pseudostem, weight of bulb and clove, number of clove in bulb and yield; and significant positive correlation with length of pseudostem and clove dry matter percentage. Factor analysis test showed that in first factor, the most positive coefficient was related to number and width of leaf, diameter of pseudostem, weight of bulb and yield, and in second factor, the most positive coefficient was related to length of leaf, length of pseudostem and weight of clove. Stepwise regression Analysis showed that leaf number per plant, length of pseudostem and length of leaf had the highest correlation with bolting. In addition, path analysis showed that, the number of leaves per plant and length of leaf had the highest direct negative effect on bolting whereas pseudostem length had the highest direct positive effect on bolting. Acording to cluster analysis of traits, all clones were divided into two main clusters including bolting and non-bolting. Results of this study showed that some morphological traits such as less leaf length, more length of pseudostem and fewer leaf numbers per plant, could be used as a morphological markers in breeding programs and garlic seed production.

The relationships of some wheat traits and theirs direct and indirect influence on the grain yield (GY) were investigated. In base of important of subject this research conducted in form of factorial in based on random complete blocks design with four replication in research field farm of Islamic Azad University of Karaj branch in 2010-2011. Experimental treatments including: Low irrigation in three levels (Normal irrigation (NI)، Non irrigation from stem elongation to anthesis (NI1)، Non irrigation from anthesis to maturity (NI2)) and phosphorous spraying in four density: 0، 4، 6، 8 kg/ha from source of Potassium de-hydrogen Phosphate (KH2PO4). According to results observed significant correlation (α = 0. 01) between GY and Biomass (TDW)، 1000 grain weight (TGW)، and harvest index (HI). In stepwise regression method under NI condition، some traits including Biomass &harvest index and under NI1 condition، grain number per ear (GNE)، ear number per m2 (EN)، plant height (PH) & unit grain weight (UGW) and under NI2 condition some traits including biomass (TDW)، harvest index (HI)، 1000 grain weight (TGW) & fertile spikelet number (NFS) remained in final model R2 was equal to 0. 97، 0/99 and 0. 997، respectively. Path analysis results showed that the biomass has a highest direct and positive effect under normal irrigation (1. 511) and NI2 condition (0. 828)، on GY، but in NI1 condition، highest direct and positive effect related to grain number per ear (GNE) trait (1/231). Among the Other traits، grain number per ear (0/849) trait، has a highest indirect effect on GY. Totally designated increasing of Biomass and grain number per ear traits are important way for increasing of GY trait.

This experiment was conducted to investigate the genetic diversity، relationship between morphological، agronomic and qualitative traits and to identify components of forage yield using some multivariate statistical methods in local sainfoin populations. The experiment was conducted as randomized complete block design with three replications in Agricultural and Natural Resources Research Center of West Azerbaijan. Results indicated that correlation coefficients of forage yield with number of branches per main stem، number of leave and number of stem were significantly positive but with harvest index leaf and degree day emergence was significantly negative. Forage yield had no correlation with plant height but plant height was correlated with number of leave. Principal component analysis revealed six component which justified more than 76 percent of the total variation، and classified as “Yield”، “Dry weight”، “Plant size”، “Harvest index leaf”، “Morphological-phenological traits” and “Flowering rate”، respectively. On the basis of stepwise regression analysis، number of stem، plant height and number of leave justified the majority of hay yield variation. Hence، these characters could be use for selecting high yield cultivars. Thus، direct effect of these three traits on forage yield were calculated 0/726، 0/226 and -0/984 respectively by Path analysis. Finally، on the basis of the current result in this research compared with previous findings، it can be concluded that multivariate statistical methods can be useful to find relationships between quantitative characters in sainfoin.