جستجوی مقالات مرتبط با کلیدواژه "عدم تعادل لینکاژی" در نشریات گروه "زراعت"

The economic value of a genotype depends on its various traits and therefore the accurate knowledge of genetic behavior and identification of genomic locus involved in controlling these traits can help the breeder to improve genotypes.

In this study, the relationship between microsatellite markers with some important agronomic and morphological traits in 130 different soybean genotypes through communication models, including the general linear model (GLM) and the mixed linear model (MLM) in 2015 was evaluated. The studied traits were including plant height, pod length, number of pod per plant, number of grain per pod, number of grain per plant, pod weight, grain weight, 100-grain weight and grain yield.

According to the molecular diversity among the 130 studied genotypes on the basis of microsatellite markers, 87 alleles were amplified by markers, of which 85 alleles (97.7%) were polymorph. Results of allelic diversity revealed averace number of effective alleles, shannonsʹs index, polymorphic information content and gene diversity Nei equal to 1.7, 0.52, 0.62 and 0.48 respectively. The results of structural analysis showed that there were three sub-populations (k=3) in the studied germplasm, so that from the 130 soybean genotypes, 34 (26.15%) belonged to first structure, 43 (33.07%) to second structure, 44 (33.84%) to third structure and nine genotypes (6.92%) to mixed structure, which were confirmed by the results of the bar plot. The association analysis of microsatellite markers with traits under a mixed linear model (MLM) indicated that 33 and 35 markers had significant relationships with the evaluated characteristics. Some microsatellite markers had significant relationships with the several traits (e.g. the relationships between Satt460 marker with plant height, pod length, number of grain per pod, and 100-grain weight), which can be due to either the pleiotropic effects or the tight linkage of genomic regions controlling these traits. The relationship between several markers with a specific trait (for example relationship between Sct_028, Sat_124, Satt359 and Satt361 markers with trait of grain yield) indicating the quantitative and polygenic inherentance of the evaluated traits.

The results of this research showed that in addition to using markers as useful markers in assessing genetic diversity in soybeans, markers that were more closely related to the genomic regions controlling these traits, to modify the population by marker assisted selection.

Barley is a major crop and the fourth most important cereal in the world. Genetic diversity is a basic component in breeding programs and is crucial for successful barley improvement. SNPs are a good marker type to study diversity. SNPs represent the most abundant source of genetic variation within the genome and are linked to heritable differences between individuals. in this study we used diverse collection of 100 winter barley (Hordeum vulgare L.) to assess genetic diversity and population structure. Population was genotyped using 3964 SNPs with minor allele frequencies (MAFs) more than 10 percent. PIC was ranged from 0.19 to 0.5 in the whole panel and it was more than 0.25 for 3352 markers. The average of PIC was varied from 0.37 (2H and 5H chromosomes) to 0.42 (3H and 7H chromosomes). strong population structure effect related to ear row number (two-row and six-row) was present in our barley collection. AMOVA analysis and Fst index showed that differentiated regions of genome are correspondence with ear row number loci. In the whole genome, average linkage disequilibrium (LD) was observed to decay at 4cM and in sub populations was more than whole panel. LD decay was more rapid in six-row cultivars compared to two-row. These results indicated considerable genetic variation in winter barley collection and could be used in barley improvement programs.

IntroductionSunflower (Helianthus annuus L.) is one of the most important crops grown mainly for edible oil. Sclerotinia sclerotiorum (Lib.) de Bary is a common and widespread pathogen of sunflower. Sclerotinia stem rot is one of the most damaging diseases of sunflower in world, causing average yield reductions of 10 to 20%. It causes total production loss under favorable environmental conditions. Hence, plant improvement projects must focus on creating of new genotypes with higher resistance against diseases. Resistance to S. sclerotiorum (Lib.) de Bary has been described as quantitatively inherited with additive and dominant gene effects. Identification of chromosome regions controlling partial resistance to sclerotinia stem rot can increase understanding about the genetic control of the diseases and developing cultivars with improved partial resistance. In this study, retrotranposon-based molecular markers associated with resistance to disease as well as some important agromorphological traits identified using general and mixed linear models in Tassel software.
Materials and MethodsA collection of 100 sunflower lines, kindly provided by several research centers in Europe, Iran and the United States, were evaluated using a 1010 simple lattice design with two replications. Each plot comprised 2 lines 5 m long, with a spacing of 65 × 25 cm between lines and plants, respectively. The experiment was conducted in 2015 at a farm in ‘Vaghaslo-e-Sofla’ village on Urmia. Five plants per genotype in each replication were inoculated with a fungal isolate collected from naturally infected sunflower plants of this farm in previous year.Some resistant and agronomical traits including percentage of necrotic area after 4, 8, 12 days inoculation, 100 seeds weight of non contaminated plants, 100 seeds weight of contaminated plants, yield per plant in non contaminated plants, yield per plant in contaminated plants, 100 seeds weight loss, and per plant yield loss were measured. The genetic profile of population was prepared with 28 rerotransposon markers.
Results and DiscussionBased on molecular marker data, the studied association panel was subdivided into two subpopulations (K=2). Association analysis using mixed linear model (MLM) identified 27 loci significantly (P

The economic value of cultivar depends on different characteristics. Thus detailed knowledge on genetic behavior and identification of genomic loci involved in control of these traits could help to breeder to improve plant cultivars. In this investigation, relation and linkage among 25 microsatellite markers with some of important agromorphological traits in 121 different rice cultivars and lines were evaluated based on GLM and MLM association models using the Structure and Tassel software. Based on the 25 microsatellite markers used in this study, population genetic structure divided into five subpopulations (K=5) that barplat results also confirmed it. In association analysis based on GLM and MLM models, 26 and 30 loci showed significant relations with the evaluated traits, respectively, and confirmed considerable variations of this studied traits. In the present study, identified common markers between of some of assayed traits such as significant relation of RM5 marker with flag leaf length and width traits and RM3355 with days to 50% flowering and plant height traits can be due to pleiotropic effects or linkage between of genomic regions involved in these traits. Also RM190 and RM6080 markers with higher R2 were related to paddy length and grain yield, respectively, that these related region could be saturated and sequenced after complementary experiments and confirmation for identification of coding genes of these traits.

This study was carried out in order to examine the contrastive relationship between seed yield and agro-morphological traits in confectionery sunflowers at molecular and phonotypical level via association mapping and sequential path model. In this study, 50 confectionery sunflower populations gathered from different regions of country were studied in completely randomized design with ten replications under pot conditions in 2012-2013. Some traits including flowering date, physiological maturity date, number of leaves, leaf length, petiole length, leaf width, plant height, stem diameter, head diameter, head dry weight, aerial part dry weight, harvest index, 100-seeds weight, single seed weight, dehulled kernel weight, dehulled kernel weight to whole kernel weight ratio, seed length, seed width, and seed dry weight per plant were measured and calculated. Path analysis revealed direct effects of head dry weight and head diameter on seed yield. Based on Bayesian model, the whole confectionery sunflower populations were classified into three sub-populations. In order to identify molecular markers associated with gene controlling agro-morphological traits variation, association mapping was carried out via mixed linear model (MLM). Some common makers were identified among yield and agro-morphological traits; six common loci between seed yield and 100-seeds weight, one common locus between head diameter and head dry weight, head dry weight and dehulled kernel weight to whole kernel weight ratio, seed width and 100-seeds weight, leaf width and head dry weight, leaf width and seed yield. Identification of common markers between yield and agro-morphological traits confirm the correlations observed at the phenotypic level.