جستجوی مقالات مرتبط با کلیدواژه « تجزیه ارتباطی » در نشریات گروه « زراعت »

IntroductionWheat is one of the most stable crop in the world, and drought stress is one of the major environmental factors that reduce agricultural products. Evaluation of genetic diversity in plant breeding program is the main basis for development and achieving self-sufficiency in the agricultural product. The objective of this experiment was to investigate the association between microsatellite markers and genomic regions controlling yield, physiological, and phenological traits in 23 accessions and two cultivars of bread wheat, as well as to evaluate the genetic diversity of the studied population in term of yield, physiological and phenological traits, and microsatellite markers under rainfed and irrigation conditions.Materials and methodsA field experiment was carried out in a randomized complete block design with three replications under rainfed and irrigation conditions in the research field of Razi University, Kermanshah, Iran, in 2016-2017. Grain yield, 15 physiological traits and six phenological traits were measured. Twenty microsatellite markers were used for molecular evaluation of the studied genotypes. Genomic DNA was extracted as bulk from 2-3 weeks old seedlings by modified CTAB method. To determine the quality and quantity of the extracted DNA, electrophoresis on 0.8% agarose gel was used. Finally, the association between microsatellite markers, yield, physiological and phenological traits in rainfed and irrigated conditions was calculated using stepwise regression analysis by SPSS23 software.Research findingsAnalysis of variance showed that there was a significant difference between the accessions for most of the traits studied. Sixteen out of twenty markers had detectable polymorphisms. The XCFD168-2D, XGWM350-7D and XGWM136-1A primers were the most suitable primers for subsequent studies. Association analysis by stepwise regression showed that in rainfed and irrigation conditions, markers XGWM350 (a3) and XGWM334 (a1) were common for physiological traits and markers XGWM642 (a1), XGWM350 (a1), and XCFD168 (a1) were common for phenological traits. The XGWM410 (a1) marker on yield, physiological and phenological traits in both conditions; XGWM265 (a1) marker on yield and physiological traits in irrigation conditions and phenological traits in both conditions; XGWM124 (a2) marker on yield and some physiological traits in rainfed conditions and phenological traits in both conditions; XGWM165 (a1) marker on physiological and phenological traits in rainfed conditions, and XGWM577 (a2) markers on grain yield and physiological traits in irrigation conditions and some phenological traits in rainfed conditions were jointly related. In addition, the most positive markers in rainfed conditions are related to the trait of rate of filing seed, and in irrigated conditions, respectively, they are related to grain yield, water use efficiency, rate of filing seed, relative water content, and days to physiological maturity traits.ConclusionAccording to the evaluation of the genetic diversity of primers XCFD168-2D, XGWM350-7D and XGWM136-1A, the most suitable primers for wheat were introduced in subsequent studies. Based on the association analysis, most of the markers produced by the primers used in this research had a high significant associated with the studied traits, and by using these primers, which have the ability to reproduce informative loci, plants can be screened at the seedling stage. Furthermore, The microsatellite primers linked to traits are suggested in marker assisted selection breeding programs to identify suitable parents for constructing mapping populations and producing new varieties.

In this research, 50 quinoa genotypes were investigated using 40 pairs of microsatellite markers (SSR) to identify the superior genotypes in terms of grain yield, the components affecting it, and the features linked to the studied traits were also introduced using Association Analysis. The study of grain yield traits and the factors affecting it showed that the traits of day to physiological maturity, panicle length, number of panicle per plant, and 1000 -grain weight were the most important traits affecting grain yield, and finally genotypes 1, 32 and 49 were the essential traits in terms of these traits. They were introduced as superior genotypes. Studying the population structure using Structure software showed two possible subgroups (K=2) in the studied population and the results of the bar plot confirmed it. The results of the correlation analysis using the general linear model (GLM) and the mixed linear model (MLM) numbers 49, 53 (GLM) and number 48, 52 (MLM) showed a significant indicator-adjective relationship, respectively, for the first year (2018) and the second (2019). Among the significant marker-trait relationships identified for different traits, the highest number of meaningful relationships were identified for grain yield and 1000-grain weight traits with 6 and 5 relationships, respectively. In conclusion, based on the results of the correlation analysis, 12 continuous markers were identified with a significant relationship with the evaluated traits during both years. Therefore, these markers can be used as fixed and stable markers in different quinoa breeding programs.

This study was carried out to investigate the relationship between microsatellite markers and some agronomic and morphological traits in wild einkorn wheat populations collected from western parts of Iran. Plant materials included 163 wild einkorn wheat accessions selected from 664 samples collected from 34 regions in of Ilam, Kermanshah and Kurdistan provinces. Seeds of selected accessions were grown in the field and the following agronomic and morphological traits were evaluated and scored in 2014-15 and 2015-16 cropping seasons: leaf length, leaf width, plant height, peduncle length, spike length, number of spikes.plant-1, number of grains.spike-1, 1000 grain weight, days to flowering, days to physiological maturity, grain yield and weight.plant-1. Analysis of variance showed significant differences among genotypes across two cropping seasons for most of the measured phenotypic traits. The genotypic evaluation was performed using 19 microsatellites (SSR) markers on the selected 163 accessions. According to the results of K statistics and two-dimensional graphics based on SSR markers, four possible sub-populations in the germplasm of wild einkorn wheat were identified. Eventually, association analysis was performed using the population structure matrix and statistical models of GLM and MLM. The results showed that based on the GLM and MLM models 87 SSR marker-trait relationships were highly significant. Also 89% markers played roles in identifying allelic locations on the chromosomes for 12 studied traits. In conclusion, the results of this study revealed that integrated uses of agronomic and morphological traits with SSR markers could be useful in evaluating of genetic diversity of wild einkorn wheat and is beneficial for identifing markers associated with important agronomic traits in breeding programs.

Maize (Zea mays L.) is one of the most important food crops worldwide and is widely used as genetic research material for studying various traits. Identification of genetic loci controlling quantitative trait is an important subject in genetics and breeding programs. In the present study, 102 maize inbred lines was evaluated for agro-morphological traits (plant height, plant height until first ear, leaf length, leaf width, leaf surface, leaf area indexear number, chlorophyll content, grain weight per plant, cob’s dry weight, cob’s diameter in first part, cob’s diameter in middle part, cob’s length, plant dry weight, days to tassel emergence, days to first ear emergence, days to second ear emergence) in completely randomized design with six replications. In the molecular experiment, 8 retrotransposon-based molecular markers primers was used for preparing the molecular profile of lines. Eight IRAP and REMAP primer combinations amplified 40 gene loci. Thirty-eight out of 40 loci (95%) showed polymorphism. The PIC values in the studied lines ranged from 0.084 for Ac/Ds to 0.383 for Pangrangja marker. The Nei’s genetic distance between lines prepared from Mashhad and Kermanshah was 0.053, between lines from Karaj and Mashhad was 0.036 and between lines from Kermanshah and Karaj was 0.032. In the analysis of population structure based on molecular markers, 102 studied lines were grouped into two subpopulations (K = 2). In the association analysis of agro-morphological traits based on two GLM and MLM methods, 24 and 12 marker-trait relationships were identified, respectively. In this study, two commons markers; Heartbraker (480) in cob’s diameter in first part and cob’s length and UBC878 × Ruda in ear number and grain weight per plant were identified with both general linear and mixed linear models. This information can be used in selecting individuals during tobacco breeding programs and developing varieties with high yield and performance.

Rice is a major source of food for more than half of the world's population. Rice is one of the smallest genomes in grain size, and it has been used as an ideal crop for evolutionary research of cereals and important crop species. Rice is a diploid plant and its genome length is short. Rainfed lowland rice is the second most important rice ecosystem, representing about 25% of the total rice production area. Fields do not receive irrigation, relying entirely on rainfall or drainage from higher lands in a watershed. Quality is of paramount importance as rice is consumed in full grain form. In Iran, rice quality is generally more important than yield, and Iranian tastes prefer aromatic rice with long grain length and low grain breadth. The purpose of this study was to identify effective markers on morphological traits, with a total of 20 indicative markers identified in both crop conditions. According to the results obtained from this assessment, they can be used in breeding programs.

This study was carried out in a research field of Gonbad-e-Kavous University in the year 2015-2016, in the form of Latis design in 3 replications, from 90 rice genotypes under normal conditions and drought stress using 11 drought tolerant markers. In this experiment, six physical traits of grain (brown and white rice) and three qualitative traits of rice grain were evaluated. These included: grain length, grain width, grain size, grain circumference, Equilibrium grain balance and Eccentricity of rice grain and percentage of protein, Amylose content and gelatinization temperature. DNA extractions were then extracted according to the CTAB method.

The beneficial results of microsatellite markers indicated that there were 54 polymorphic alleles, with the highest number of RM333 and RM589 with 7 alleles. In the analysis of the main components of SSR markers related to drought tolerance, the first 10 components were able to justify 55.58% of the variation. Clustering results divided genotypes into six groups. Investigating the adhesive patterns formed on acrylamide gel from 11 markers on 90 rice genotypes. The genotypes were grouped together in order to match the allelic pattern. Amylose content, protein content, gelatinization temperature for qualitative traits and quantitative traits of grain length and width (brown and white rice) of each group as a measure of groups. A comparison was made for drought tolerance, with a total of 20 groups identified. The results of the analysis of the relationship between the measured traits showed that among the 104 effective alleles on the traits, the effect of the RM6349-D allele with 9.99 had the greatest effect on the traits of the grain environment. Seedlings are affected by 8 alleles, the equivalent diameter of seeds with 7 alleles, length and area characteristics of seedlings with 6 alleles

Band pattern showed that genotypes can be grouped into a group in terms of matching the allelic pattern. The analysis of the main components of SSR-related drought tolerance markers with 10 components could justify more than 50% of the variation. Cluster analysis by line grouping identified the value of each group for the traits assessed.

Intersimple sequence repeat (ISSR) markers were evaluated in order to identify informative markers associated with drought tolerance indices in bread wheat (Triticum aestivum L.) genotypes. Eighteen ISSR primers amplified 92 loci among 20 bread wheat genotypes. Polymorphic information content (PIC) ranged from 0.46 (UBC-857, UBC-864, UBC-867, is9) to 0.21 (is7), with an average of 2.05. Stepwise regression analysis between molecular data as independent variable, and parametric stability statistics as dependent variables was performed to identify informative markers associated with the parametric stability statistics. Most of the used ISSR primers showed significant association with the parametric stability statistics. Stability statistics included Finlay and Wilkinson’s coefficient of regression, Perkins and Jinks’s coefficient of regression, MBIW, Lin and Binns’s superiority index, SFi and NP (2)i were explained by more primers. ISSR markers, UBC-848, UBC-869 and is5 showed the most association with stability statistics. It is possible to use these markers along with stability statistics in wheat breeding programs for identification of stable genotypes and suitable parents to produce mapping populations. Also, these results could be useful in marker- assisted breeding programs when no other genetic information is available. Some of ISSR markers were associated with more than one trait in multiple regression analysis. Such an association may arise due to pleiotropic effect of the linked quantitative trait locus (QTL) on different traits.

Identification of informative markers associated with morphological traitscan be important in breeding programs specifically in selection of elite plants and constructing genetic maps. In this study, association analysis was used to detect informative markers. This technique is applied to study the relation between phonotypic and genetic diversity which allows subsequent constructing genetic maps. Stepwise regression analysis was used to determine the association between 15 morphological traits and 10 ISSR markers in 27 Iranian melon (Cucumis melo sp.) accessions. The 10 ISSR primers generated 88 polymorphic markers. The average number of ISSR markers generated was 17.2 per primer and the level of polymorphism was 51.2%. Polymorphism information content (PIC) was ranged from 0.15 for (AC)8G to 0.36 for (AG)8T and (CA)8A. Marker index was ranged from 0.54 (for (AC)8YG) to 6.67 (for (AG)8T). Minimum and maximum number of markers was found for placenta diameter (7 markers) and seed diameter (27 markers) respectively. Maximum total adjusted coefficient of determination (R2) (99.7 %) was estimated for 100-grain weight.Results indicated that the use of markers having high linkage with morphological traits can also be utilized to identify informative markers associated with these traits. This result showed that relation between primers and morphological traits is independence of marker index and polymorphism information content.

Identification of quantitative trait loci is one of the important issues in breeding program especially under stress condition. Plant material in the present study was a natural population including 72 tobacco genotypes. In order to apply osmotic stress، Mannitol with 0. 33 Molar concentrations was used. The genotyping of individual were performed using 21 out of 35 primer combinations of AFLP markers. After measuring of eight traits including total dry weight، dry weight of shoot، dry weight of leaves، length of highest root، total dry weight of root، length of longest leaf، length of longest stem and dry weight of root to dry weight of shoot ratio، in order to perform association analysis and identify linked markers controlling loci five statistical models were used by TASSEL software. These models were GLM and MLM using data set of phenotype and genotype data، population structure data (Q)، principle components (PC) and Kinship data derived from general similarity in genetic background arising from shared kinship (K). For all eight traits common in all models and the markers with explanation of the most phenotype variations were identified and discussed. For plant total dry weight E110-M160-3، for root dry weight E080-M150-4 and for dry weight of shoot E080-M140-23 with the highest coefficient of determination (19. 9، 23 and 14. 9% respectively) were identified as the most important markers. In total، the numbers of identified markers by GLM were more than MLM model. Considering the results، it will be expected that detected AFLP markers in the present study can be used in marker assisted selection programs after confirmation and specification being specified with high confidence.

This study was carried out in order to evaluate allelic diversity of microsatellite markers in QTL region for salinity tolerance on chromosome 10 in rice and evaluation of agronomical traits of some Iranian rice cultivars in salinity stress along with two tolerant (Pokkali) and sensitive (IR29) check varieties, and association analysis for morphological traits using microsatellite markers. Based on the phenotypic data genotypes were categorized into 3 different groups (sensitive, semi tolerant and tolerant). Based on the molecular results, RM6100 marker at this chromosomal region, is introduced as the effective marker for identification of salt tolerance genotypes at reproductive stage and most traits of related to yield components, showed significant association with this marker, thus suggested as informative and benefit marker in breeding program of rice. Likewise, grain weight showed significant association with all the under studied markers at saline condition, which is indicator of the importance of this chromosomal region in controlling of this trait. Therefore based on this study using of marker information of this chromosomal region can be used in breeding of rice to produce high yielding and tolerant rice cultivars.