جستجوی مقالات مرتبط با کلیدواژه « تجزیه خوشه ای » در نشریات گروه « علوم پایه »

Rice is one of the most important food products in the world. Soil salinity reduces the yield and quality of rice. For the development of new cultivars and the cultivation of rice in saline environments, screening rice cultivars to identify salinity-tolerant cultivars is crucial. In this study, the morphophysiological characteristics of 42 rice genotypes were examined in split plots using a completely randomized design with three replications in hydroponic conditions, with NONA BOKARA representing as a tolerant control and IR29 as a sensitive control to salinity in the seedling stage at two levels of 0 and 100 mM salinity (from the source of NaCl, CaCl2, and Na2SO4). The variance analysis results revealed that the effect of rice genotypes, salinity, and their interaction on all traits studied was significant at the 1% level of probability. Additionally, the findings of this study demonstrated that under salt stress, the root and stem length, fresh and dried weight of the stem and root, the electrolyte leakage content, biomass, and chlorophyll content were all drastically decreased. But under salt stress, the proline content increased. Moreover, the results of the correlation study revealed a significant and positive correlation between biomass features and both shoot fresh weight and shoot dry weight. According to the results of the principal component analysis, the biomass, shoot fresh and dry weight, shoot length, and root weight had the largest positive effects on the first component. The results of cluster analysis showed that 12 genotypes, along with NONA BOKARA were included in the tolerant cluster, which can be used in breeding programs to develop salinity-tolerant cultivars.

To evaluate the effect of drought stress on grain yield, yield component, morphologic and phonological traits on 30 genotypes of wheat, an experiment in the form randomized complete block with three replication at 2 levels of irrigation (normal and stress), was carried out. Results showed that the studied genotypes were significantly different in terms of grain yield, 100-seed weight, number of seeds per pod, number of pods per plant, day to maturity, and seed size under stress and non-stress conditions. According to the results, it can be seen that Kavir, Pishtaz and Helmand cultivars showed the lowest yield reduction and Navid, Karim and Alvand cultivars showed the highest grain yield decrease among all cultivars. The analysis of tolerance index correlation showed index of tolerance stress, using mean and using numeral mean are the best indexes for identifying genotype with high yield in this test According to the results of phenotypic correlations, stepwise regression, path analysis and principal component analysis in both normal and stress conditions, it can be concluded that, expected that the traits of number of spike in plant, total spikes weight, biological yield, main spike of weight, were most important and effective traits affecting yield and considering that among the genotypes, The highest diversity was observed for these traits, therefore selecting and breeding for these traits can ideally be improved the yield Genotype grouping in both conditions was conducted based on studied traits with UPGMA method, in both conditions investigated genotypes were grouped in five clusters.

Castor (Ricinius communis L.) is one of the oldest medicinal plants in the world. The assessment of genetic diversity in castor beans plays a vital role in identifying superior genotypes to use in plant breeding programs. For this reason, the diversity and genetic association of 22 castor ecotypes were investigated. Out of 26 screened primers, 19 primers that produced the most polymorphic bands were used. Totally, these primers generated 188 bands, of which 180 bands (95.58 %) were polymorphic. The studied ecotypes were divided into two separate group’s using cluster analysis. The highest similarity was observed between ecotypes 4 and 5 (collected from Sari) and the lowest similarity was observed between ecotypes 1 and 14 (Sari and Babolsar).The highest Nei's genetic diversity (H) and Shannon index (I) were observed in population No. 2 including 12 ecotypes. According to the genetic structure of populations performed by Structure software, ecotypes were divided into two subpopulation clusters. The molecular analysis of variance showed that 37% of genetic variation attributed to between group's and 63% to within group's, which can be used in its breeding programs.

Understanding the genetic diversity and the relationships between species and plant ecotypes is an important step to preserve genetic resources. In this study, the genetic diversity of 15 Guava (Psidium guajava) genotypes was investigated using Rapid and ISSR markers in the molecular breeding laboratory of the Faculty of Agriculture, University of Birjand. Nine out of 36 RAPD primers and six out of seven ISSR primers showed polymorphism. In total, RAPD and ISSR primers amplified 80 and 35 bands, respectively, which 54 out of 80 (67.5%) and 25 out of 35 (71.42%) bands were amplified by RAPD and USSR primers, were polymorphic, respectively. The lowest and highest polymorphic information content was observed in RAPD marker in OPAB09 primer (0.13) and OPAB17 primer (0.40) and in ISSR primer in ISSR3 primer (0.19) and ISSR5 primer (0.37), respectively. According to the RAPD marker, genotypes M5 with M4 (0.83) had the highest and genotypes CH5 with R4 (0.19) had the least similarity, respectively. According to ISSR marker, genotypes R2 with R3 (0.86) had the highest and M1 with CH4 (0.12) had the least similarity, respectively. The Cluster analysis classified genotypes according to RAPD marker into five groups and according to ISSR marker into three groups, respectively. In total, the results showed that there is sufficient genetic diversity among Guava genotypes and RAPD and ISSR are useful markers in identifying polymorphic regions and estimating genetic distance and managing genetic resources of Guava.

Salinity is one of the most significant environmental stresses for sustainable crop production in the world's agricultural lands. Tomatoes are sensitive to salinity, and it is possible to create a tolerant genotype by evaluating the diversity among tomato genotypes under salt stress and using this diversity in tomato breeding programs. Based on this, in the current study, 22 tomato genotypes were evaluated under salt stress in a randomized complete block design with three replications. In this research, different stress tolerance indices were used to evaluate genotypes under salt stress. Stress Tolerance Index (STI), Tolerance Index (TOL), Geometric Mean Productivity (GMP), Mean Productivity (MP), Harmonic Mean (HM), Yield (Y), Yield Stability (YSI) and Stress Sensitivity (SSI) were calculated based on the total dry weight under control and stress conditions. The results of analysis of variance and mean comparison showed that there is a statistically significant difference between the studied tomato genotypes for two traits, total dry weight and total fresh weight, in two conditions of salt stress and control. These results confirmed the existence of diversity between genotypes in their morphological characteristics. The YP trait showed the highest correlation (0.9) with the MP index and the YS trait showed the highest correlation (0.91) with the HM index, and these indices are suitable for evaluating tomato genotypes under salt stress in the seedling stage. Based on bi-plot analysis, the G10 genotype was the most tolerant genotype, and after that, the G2, G22, G19 and G5 genotypes showed tolerance to salt stress. The cluster analysis divided the genotypes into three separate categories, which showed different behaviors during the transition from a non-stressed environment to a stressed environment. Based on tolerance indices and grouping methods, genotype G10 was identified as a tolerant genotype to salt stress, which can be used as a parent in hybridization and selection of tolerant genotypes.

One of the basic requirements before starting any breeding program is to identify the relationships and genetic diversity in the population and to recognition the target traits. This study was conducted to investigate the genetic diversity among some European pear cultivars using fruit's key traits of these cultivars. Eleven European pear cultivars were used for this study along with two control cultivars Shahmiveh and Sardrodi. Thirteen cultivars were planted in a randomized complete block design with three replications and during three crop years ten key traits including fruit weight, fruit length, fruit diameter, fruit texture firmness, fruit length to diameter ratio, TSS, pH, acidity, fruit set and fruit yield were recorded for each tree. Combined variance analysis of the data showed that the cultivar component was significant for all studied traits at the level of 1% probability. The highest fruit weight among the cultivars belonged to Nart cultivar with an average fruit weight of 374.38 g and the highest fruit yield belonged to Mellina cultivar with a yield of 10.07 kg per tree. With the principal component analysis, the studied traits in the first four components explained 87.66% of the total variance. With cluster analysis, Nart cultivar was placed in a cluster alone due to the high differences in its traits and appearance, and Decandel, Pacham's Triumph, Abate fetel and Mellina cultivars were distinguished as superior from the two control cultivars due to their favorable fruit characteristics.

This study was conducted to comprise and grouping 16 different durum wheat genotypes for activities of antioxidant enzymes at Research Laboratory of Department of Plant Production and Genetics, University of Maragheh. Seedlings grown in aeroponic way, after 4-5 leaf stage, were exposed to cadmium stress using 250 µM. Then, dry weight of leaf, enzyme activities of catalase (CAT), glutathione s transferase (GST), guaiacol peroxidase (GPX), ascorbate peroxidase (APX), amount of malondialdehyde (MDA) and hydrogen peroxide (H2O2), elements Cd, Cu, Fe, Zn and Mn were measured. Cluster analysis categorized the genotypes into three distinct groups. The genotypes of second group (1, 3, 4, 6, 8, 9, 10 and 12) had the highest values of dry weight of leaf, Fe and Zn and the lowest values Cd, Cu, H2O2, CAT, APX, GPX, GST and MDA. These genotypes were known as tolerant genotypes which those may be applied in durum wheat breeding programs for cadmium tolerance.

Drought stress during seed germination of most plants disrupts many physiological processes and ultimately prevents root emergence and reduced germination percentage. In this regard, the effect of osom-priming with different concentrations of polyethylene glycol on the germination characteristics of Allium L. seeds of seven species, including A. cristophii Trautv., A. giganteum Regel, A. longisepalum Bertol, A. pseudobodeanum R.M. Fritsch & Matin, A. stipitatum Boiss., M.B. A. rubellum, M.POP. & Vved. A. vavilovii, in the case of drought stress, was investigated as a factorial in a completely randomized design with three replications. Experimental treatments included priming with different concentrations of polyethylene glycol 6000 (-0.6, -0.9, -1.2 MPa and control) in 5ºC. The results showed that with increasing the concentration of polyethylene glycol, germination indicators increased. The most effective concentrations of polyethylene glycol to improve germination and viability of seedlings were A. pseudobodeanum, A. vavilovii, A. cristophii, A. stipitatum, -1.2MPa, in A. giganteum, -0.9Mpa. However, in two species, A. rubellum and A. longisepalum, control treatment showed the best germination characteristics. The results of cluster analysis of seven species of Allium were divided into five groups. A. pseudobodeanum so that the greatest improvement in germination and viability at high concentrations of polyethylene glycol was separated from other species. Due to the fact that these species are of great agricultural, medicinal and ornamental value, they can be used optimally by modifying and creating suitable varieties.

In order to Identification of Ranunculaceae, morphological information of Delphinieae (Delphinium, Aconitum and 2 species of Consolida) was investigated to clarify taxonomic grouping this tribe. Delphinieae contains annual and perennial herb that similar in many anatomical and morphological traits. It was performed Morphological studies on 49 quality and quantity characteristics. Statistical analysis was conducted by SPSS software and cluster analysis was performed by Average linkage method. PCA analysis was performed and the most variable character were identified. The first group includes Aconitum species and the second main group includes Delphinium and Consolida taxa (two species of Consolida were studied). Principle Component Analysis Showed that most variable character include: root form, tepal form, stem striate, stem color, bract form and anther color. Based on the phonogram obtained, the results of numerical taxonomy studies confirm the classical classification available in most flora. The findings of this study confirm that D. elbursense var. gymnobotrys could be have higher taxonomic level.

Exact evaluation of the amount and distribution of genetic diversity in plants is essential for developing a strategy for conservation and use of genetic resources. Study, the genetic diversity of 40 genotypes of bread wheat (Triticum aestivum L.) was investigated using 10 Inter Simple Sequence Repeat (ISSR) markers and four Random Amplified Polymorphic DNA (RAPD) markers. The 10 ISSR primers produced 92 polymorphic bands with an average of 9.2 polymorphic bands for each primer and the polymorphic percentage was 86.79%. Also, four RAPD primers produced 19 polymorphic bands with an average of 4.75 bands for each primer, and the average polymorphic percentage was 67.85%. High levels of effective number of alleles, Nei index, Shannon index, and the Polymorphism information content of ISSR markers for UBC813, UBC816 and UBC824 primers, and RAPD markers for OH-04 and OPA02 primers was indicated the high efficiency of these primers in differentiating the studied wheat genotypes in this research. Cluster analysis using UPGMA method based on Jaccard's similarity coefficient based on the whole polynomial bands of ISSR and RAPD markers divided wheat genotypes in two separate groups. Also, principal coordinates analysis and determining population structure based on Bayesian method with STRUCTURE software placed the cultivars in two groups and confirmed cluster analysis results. Molecular analysis of variance showed that within groups’ diversity is more than between groups’ diversity. Information obtained from this research and variation in wheat cultivars can be used in the breeding programs for yield improvement.

One of the main issues in plant breeding is the knowledge of situation of conservation in plant genetic resources. This research was conducted to study on on-farm conservation efficiency by using molecular markers and morpho-phenological traits in soybean landraces. The subjected plants had been collected in two times with 10 years intervals. Twenty-eight accessions were planted in a field and subsequently characterized their traits according to standard descriptors. Eighty samples of DNA were extracted by the CTAB method, then RAPDs fragments were produced using 24 10-mer(base) selected-primes. Data was used in the cluster analysis as well as to estimate genetic variability within accessions using NTSYS and SPSS softwares. These analyses showed the genetic relationships among accessions. In the dendrogram, only in one accession the individuals in the new and old accessions appeared in the different clusters. These two accessions were different in their morpho-phenological traits too. Genetic variability coefficients in the new landraces were higher than the old ones, exception to one landrace. As soybean is highly self-pollinated (99.9%) crop, high genetic variability in the new landraces could not due to allo-pollination by foreign pollen. But, it could be because of seed exchange by farmers. In this research was shown that the genetic variability coefficient within the improved line is too much less than landraces. Also, this research showed that on-farm conservation could not conserve genotypes, on the other hand this type of conservation will cause some changes in genetic structures of genetic resources during the times.

Rice is one of the most important food crop which is the staple food for more than half of the world population. The purpose of this study was to evaluate the physical and chemical properties such as plant height, panicle length, number of effective tillers, total number of grains, number of filled grains, number of unfilled grains, 1000-grain weight, biological yield, economic yield, harvest index, chlorophyll index, growth period, total Phenol (TP), antioxidant capacity based on 2,2-Diphenyl-1-Picryl Hydrazil (DPPH) with 30 rice genotypes in a randomized complete block design in the experimental field of Amol Rice Research Institute. Results showed that Amol 1 and Bijar rice varieties had significantly higher antioxidant activities and total phenolic than the other samples examined in this study, respectively. The highest total number of grains, number of filled grains and 1000-grain weight were observed in genotype IR56. The genotypes were grouped into five clusters based on agronomic traits using UPGMA method. The highest mean of yield was related to the fourth cluster and the lowest of this attribute was related to the fifth cluster. Principal components analysis (PCA) explained 79.01% of variation and economic yield, total number of grains, and number of filled grains played the main Experimental Field role. Two principal components accounted for 43% of the raw data of the yield-related traits. The results of this research indicated that use of economic yield, total number of grains, and number of filled grains could be applied as a breeding strategy to obtain high yield rice cultivars.

Salinity is one of the major abiotic stresses that affects physiological processes of plants and reduces crop growth and yield. In order to study the effect of salinity stress on some physiological and agronomical traits of Thymus daenensis subsp. daenensis ecotypes and their classification, a factorial experiment was carried out using randomized complete block design with three replications in Abarkouh city in 2018. Experimental treatments were twelve Thymus daenensis subsp. daenensis ecotypes and three salinity levels including 0 (non-stress), 60 and 120 mM NaCl. Analysis of variance revealed that the difference among ecotypes and among salinity levels were significant (p<0.01) in all studied traits. Salinity stress led to a significant decrease in concentration of total chlorophyll, carotenoid, concentration of potassium, relative water content and shoot dry weigh and an significant increase in concentration of proline, concentration of sodium, sodium to potassium ratio and ion leakage. Studied ecotypes under two salinity levels including 0 (control) and 120 mM NaCl using cluster analysis based on Ward method and by using Eucilidian distance classified into three groups. Khoramabad1, Khoramabad2, Arak2, Fereydunshahr and Semirom ecotypes were suggested as salt tolerant ecotypes based on cluster analysis using all studied traits.

In order to investigate the response of 15 maize S6 lines to drought stress, a split plot design based on randomized complete block design with three replications was conducted in 2015 year at the research field of Graduate University of Advanced Technology, Kerman, Iran. In this study, the main factor was stress at two levels (normal with five days irrigation and low irrigation with ten days irrigation) and the sub-factor was maize line at 15 levels. The results showed that there were significant differences between stress levels and lines for all studied traits (chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, soluble sugars, protein and proline content). Mean comparison of lines showed that lines 9, 3 and 5 had the highest proline content under drought stress conditions. The lowest phenotypic coefficient of variation was for total protein (2.59) and the highest for proline (74.17). Cluster analysis divided the studied lines into four, five and six groups in normal, drought and mean conditions, respectively, and the similarity of their grouping was high. Based on the results of cluster analysis and mean comparisons, lines with high genetic distance were grouped together. Thus, three groups, each with five lines, were found to be used in the planning of breeding projects and cross-breeding programs. Line 9 also showed a high mean for most of the studied traits in both conditions and it can be considered as a promising line in future experiments.

Many Rumex L., species are used as herbs or medicines. Species of this genus are rich in ascorbic acid, oxalic acid, phenolic acid, flavonoids, phenolic compounds, anthraquinone, naphthalene, sterol, and trypthenes. Considering the importance of this research, in order to study the genetic diversity and phylogenetic relationships of 54 masses of Rumex, using morphological traits in a completely randomized design. 20 quantitative and qualitative traits were measured and recorded. Based on the comparison of the mean of measured traits, it was observed that the maximum length of the flatness belongs to the mass 54 and the lowest value is 41. Also, important traits such as leaf length, leaf width, petiole diameter and chlorophyll content were most diverse. The results of factor analysis, the first three factors, explained a total of 24.25% of the total variance, which could be effective in separating the masses. Different populations in 5 to 25 groups were classified into three groups. The use of traits in grouping traits showed that the use of these traits is a very good criterion for grouping this large number of traits. According to the results of this study, it seems that the masses 24, 22, 18, and 19 can be identified by having a higher number of plants per plant, a large number of leaves and a petiole standing, the best of the masses for the measured traits.

In order to evaluate the effect of drought stress on yield and the other related traits, 14 rice genotypes (including five varieties of landrace and introduced varieties) in a randomized complete block design with three replications in two environments without stress (flooding) and drought stress in the field Research located in Aliabad (under the supervision of Gonbad Kavous University) was studied. Irrigation of experimental farm in both the flood and drought were flooded until maximum tillering stage. Irrigation was performed every 25 days until the end of the season from 40 days after maximum Tillerin). Analysis of variance showed significant differences among genotypes for all traits in both conditions. The average yield of the genotypes in the normal and stress conditions lR83752-BB-12-3 and was Sepedroud. Panicle weight (0.85**) under stress (flooding) and root volume (0.98**) in drought stress conditions, the highest positive correlation with grain yield were Significant. Path analysis results showed that different traits were involved in justifying grain yield under non-stress and drought stress conditions, so that in non-stress condition, number of panicle and in drought condition, number of filled grain per panicle had the highest direct and positive effect on grain yield. In grouping cultivars based on cluster analysis using ward method, cultivars were divided into three groups under normal conditions and stress. The results of cluster analysis showed that Pegaso, IR83752-B-B-12-3 and Sepidrood cultivars, which had more volume, fresh weight and root dry weight than other cultivars, were in the drought tolerant group.

This study was conducted to assess genetic diversity among the 32 tall fescue half-sib families using a randomized complete block design (RCBD) experiment in the four replicates. Based on analysis of variance, significant differences were observed among studied genotypes at the probability of 1% for plant height, canopy diameter, days to heading, days to pollination, crown diameter, fresh forage yield, dry forage yield, number of stem and seed yield in first harvest and in canopy diameter, crown diameter, fresh forage yield and dry forage yield in second harvest. Based on the results of mean comparisons, highest dry forage yield in the first harvest was obtained in genotype 32 by 758.5 grams. Principal component analysis by considering eigenvalues greater than one, caused to introduction of three components which determined 80.5% of the variation among the samples. In cluster analysis, the greatest of distinction between the groups was achieved with three clusters, and by cutting the dendrogram genotypes in three groups. According to the results, the third cluster was superior to other two clusters in terms of most traits. The genotypes of third cluster, according to the value of this cluster in terms of forage yield and seed yield will be of particular importance in breeding programs. In the breeding of cross-pollinated forage crops, success in selection depends on creating diversity by genetic recombination and achievement of heterosis. Due to the distance between groups 1 and 3, probably the most successful crosses will be achieved among genotypes of these two groups.

Summer savory (Satureja hortensis L.), belonging to the Lamiaceae family, is one of the most important medicinal plants. This plant is used in the wild and cultivated forms. In this study, the genetic diversity of 20 accessions of S. hortensis from different places of Iran and other parts of the world were characterized by morphological, phytochemical, and essential oil yield traits. The data was analyzed using univariate and multivariate analyses. The results of the analysis of variance showed a significant difference between the studied characteristics. The results of the morphological analysis showed that traits such as the leaf number, bract number, 100-seed weight, and seed number per plant were very diverse. Bulgaria and Uzbekistan accessions were best in most of the traits and essential oil yield was higher in Karaj accession. The correlation coefficients among traits showed that the plant diameter had the highest correlation with the leaf number trait (0.99) and leaf number had a significant positive correlation with all traits. Factor analysis indicated that the six factors explained 85.85 of the variability among the accessions. Cluster analysis divided the accessions into four major groups. Considering the grouping, there was no relationship between genetic diversity and the geographical distance of the accessions. The results confirmed a considerable genetic variation among S. hortensis accessions.

Delphinieae tribe in Ranunculoideae subfamily has about 700 species. Delphinium is one of the genus in Delphinieae that has 29 species and two subgenus in Iran. Differences between subgenera are in the form of seed and vegetative period. Olighophyllon and Delphinium, which are perennial and annual species, respectively. In this study pollen grains of 27 species were examined by Scaning Electron Microscope. Pollen grains were grouped into spheroidal, prolate-spheroidal and subprolate-perprolate. In this genus surface ornaments of grain were seen as scabrate ،microperforate scabrate- and scabrate-reticulate. To investigate similarities among genus for palynology characteristics, cluster analysis was performed by SPSS. Also, PCA analysis was performed and the most variable characteristics were determined. The results showed that the first component included P / E ratio traits, polar axis length and colpi length size, and the second component included equatorial axis diameter and mesocolpium size traits, which played the most important role in the similarities and differences of taxons. Micro-morphological studies of Delphinium pollen in this study show that closely related species do not have very similar morphological characters. Pollen characters could not group the species studied. Pollen Phenogram in this study provides useful information to determine the status of D. elbursense, D. saniculifolium, D. aquilegifolium, and many other species.

this species Widely distributed in the world and have adapted to the varied weather conditions. Different environmental conditions and diet are two important factors that have effect on making diversity. Different studies have shown, Skull sustained only skeletal components in different environmental conditions.so, using them as Evaluation of morphometric changes of species. Therefore The analysis was limited only to the skull Rabbit. The aim of this study is surveying Genetic diversity and relationships between morphometric traits measured in 50 Skull Rabbit samples in five western province with a random sampling. totally 40 morphometric traits were measured. Group of measured traits were carried out by Spss and Ward method. As well as that, we used Pearson correlation to study correlations between traits were measured at the level of 99%. Fitting Darngarh have shown From the Euclidean distance of fifteen Species were divided into three groups (A, B , C). Continue fitting the Euclidean distance of ten Species based on morphological traits divided into four distinct groups. The correlation coefficients between traits showed that there is a high positive correlation at the level of 1% between some traits (r>80%) such as: Сondylobasal length، Palatal length. Zygomatic width، Greatest width. Least interorbital width، Postorbital width. Least interorbital width، Width of skull behind zygomaticorches. In addition to that there is a negative correlation at the level of 1% between The top row of teeth and Lower jaw height.