Retrotransposon-microsatellite Amplified Polymorphism Research Articles

5-Aminolevulinic acid treatment mitigates pesticide stress in bean seedlings by regulating stress-related gene expression and retrotransposon movements

Overdoses of pesticides lead to a decrease in the yield and quality of plants, such as beans. The unconscious use of deltamethrin, one of the synthetic insecticides, increases the amount of reactive oxygen species (ROS) by causing oxidative stress in plants. In this case, plants tolerate stress by activating the antioxidant defense mechanism and many genes. 5-Aminolevulinic acid (ALA) improves tolerance to stress by acting exogenously in low doses. There are many gene families that are effective in the regulation of this mechanism. In addition, one of the response mechanisms at the molecular level against environmental stressors in plants is retrotransposon movement. In this study, the expression levels of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR), and stress-associated protein (SAP) genes were determined by Q-PCR in deltamethrin (0.5 ppm) and various doses (20, 40, and 80 mg/l) of ALA-treated bean seedlings. In addition, one of the response mechanisms at the molecular level against environmental stressors in plants is retrotransposon movement. It was determined that deltamethrin increased the expression of SOD (1.8-fold), GPX (1.4-fold), CAT (2.7-fold), and SAP (2.5-fold) genes, while 20 and 40 mg/l ALA gradually increased the expression of these genes at levels close to control, but 80 mg/l ALA increased the expression of these genes almost to the same level as deltamethrin (2.1-fold, 1.4-fold, 2.6-fold, and 2.6-fold in SOD, GPX, CAT, and SAP genes, respectively). In addition, retrotransposon-microsatellite amplified polymorphism (REMAP) was performed to determine the polymorphism caused by retrotransposon movements. While deltamethrin treatment has caused a decrease in genomic template stability (GTS) (27%), ALA treatments have prevented this decline. At doses of 20, 40, and 80 mg/L of ALA treatments, the GTS ratios were determined to be 96.8%, 74.6%, and 58.7%, respectively. Collectively, these findings demonstrated that ALA has the utility of alleviating pesticide stress effects on beans.

Chromosomal polymorphism of the Ceratocystis fimbriata species complex in Brazil

Ceratocystis fimbriata is an important pathogen that causes wilt in several plant species. Despite the importance of this pathogen, knowledge about its karyotypic polymorphism and genomic architecture is limited. The main objective of this study was to investigate the karyotype of isolates of the C. fimbriata species complex from different host plants and geographical origins in Brazil. First, the identity of the isolates was confirmed conducting multilocus sequence analysis (MLSA) phylogeny using β-tubulin (TUBB), translation elongation factor 1α (TEF-1α) and mating-type (MAT1 and MAT2) gene sequences. To investigate the chromosomal polymorphism, two conditions of pulsed-field gel electrophoresis (PFGE) were used and the karyotypes of the isolates obtained. The retrotransposon-microsatellite amplified polymorphism (REMAP) molecular marker was utilized to assess the genetic variability among isolates. In the MLSA utilizing the concatenated gene sequences, Ceratocystis cacaofunesta and C. fimbriata formed separate clades, but considerable variation among C. fimbriata isolates was observed. Polymorphism in chromosome number and size was found, indicating the existence of genomic differences among isolates and occurrence of chromosomal rearrangements in the species complex. The number of chromosomes varied from seven to nine and the estimated minimum chromosome sizes were estimated to be between 2.7 and 6.0 Mbp. Small polymorphic chromosomes ranging from 1.2 to 1.8 Mbp were observed in all isolates, raising the hypothesis that they could be supernumerary chromosomes. REMAP analysis revealed a high genetic variability and that isolates from the same host tend to group together in a same cluster. Our results bring new insights into the chromosomal diversity and genome organization of the C. fimbriata complex.

High genetic diversity in Aegilops tauschii Coss. accessions from North Iran as revealed by IRAP and REMAP markers

BackgroundAegilops tauschii Coss. as a donor of wheat D genome has an important role in wheat breeding programs. Genetic and phylogeographic diversity of 79 Ae. tauschii accessions collected from north and northwest of Iran were analyzed based on retroelement insertional polymorphisms using inter-retrotransposon amplified polymorphism (IRAP) and retrotransposon-microsatellite amplified polymorphism (REMAP) markers. ResultsIn total, 306 and 151 polymorphic bands were amplified in IRAP and REMAP analyses, respectively. As a result, a high level of polymorphism was observed among the studied accessions as revealed by an average of 25.5 bands per primer/primer combination and mean PIC value of 0.47 in IRAP and an average of 25.16 bands per primer combination and mean PIC value of 0.47 in REMAP. Genetic relationships of the accessions were analyzed using distance- and model-based cluster analyses. ConclusionThe result showed that genetic distance did not seem to be related to geographic distribution, and the accessions could be divided into three groups, which was further supported by principal coordinate analysis. These results on genetic diversity and population structure of Ae. tauschii in Iran should provide important knowledge on genetic resources and their applications in wheat breeding programs.

Comparative retrotransposon analysis of mutant and non-mutant rice varieties grown at different salt concentrations

This study investigated the effects of retrotransposon movements on the regeneration of 15- and 30-day-old leaves and roots of four different rice varieties grown in tissue culture medium at different salt concentrations (0, 50, 100, and 200 mmol/L) by Inter Retrotransposon Amplified Polymorphism (IRAP) and Retrotransposon Microsatellite Amplified Polymorphism (REMAP) polymerase chain reaction (PCR)-based marker methods. The study used Hopi, Houba, Osr30, Tos17 primers for IRAP analysis. The (GA)9C ISSR primer was used with four IRAP primers in REMAP analyses. There were different band profiles and polymorphism results between different salts concentrations of the same variety and various rice varieties. We observed that the polymorphism ratios for Houba ranged from 0 to 98% in IRAP and REMAP analyzes in the calculation made with the Jaccard similarity index in mutant samples. We report that mutant varieties give more valuable IRAP and REMAP results than non-mutant varieties. The results reported in this study contribute to understanding the effect of salinity stress on rice in terms of retrotransposon-based molecular markers. These results suggest that all tested retrotransposons are still active, causing genomic polymorphism among rice plantlets.

Molecular analysis of somaclonal variation in Linum usitatissimum and L. album

Flax plant (Linum usitatissimum) is an important oilseed crop, with an annual world production of around three million tons. Flax is a crop with a rather low genetic variability and agriculturally important traits. Biotechnology and somaclonal variation is a potential way of inducing genetic variation in Linum. Therefore, we studied the occurrence of somaclonal variation and genetic variability in both flax plant and its wild relative, Linum album. We used a combination of simple sequence repeats (SSRs), and Expressed sequence tag SSRs (EST-SSRs), as well as inter-retrotransposon amplified polymorphism (IRAP) and retrotransposon-microsatellite amplified polymorphism (REMAP) molecular markers for genetic analyses. Tissue culture regenerated plants differed from mother plants in their morphological and genetic content. Moreover, some new bands were observed in regenerated plants in all molecular markers studied, probably due to soma clonal variation. The genetic changes occurred seemed to be genotype-dependent as evidenced by network analysis. This study reveals the potential application of somaclonal variation to induce new genetic variation in flax plant which may be of use in its future breeding.

Assessment of genetic diversity of cultivated and wild Iranian grape germplasm using retrotransposon-microsatellite amplified polymorphism (REMAP) markers and pomological traits.

Understanding the genetic diversity and relationships between genotypes is an effective step in designing effective breeding programs. Insertional polymorphisms of retrotransposons were studied in 75 cultivated and wild grape genotypes using retrotransposon-microsatellite amplified polymorphism (REMAP) technique. In the morphological part of work, seven pomological traits with a high breeding interest were also analyzed in the cultivated genotypes. A total of 328 markers were produced by 42 primer pairs, out of which 313 markers (95.43%) were polymorphic. Number of markers ranged from 4 in loci Tvv1Fa-873, Vine1-811, Gret1Ra-855 and Tvv1Fa-890 to 12 in locus Vine1Ra-841 with an average value of 7.45. Similarity values based on Dice's coefficient among all 75 grapevine genotypes varied from 0.41 to 0.77. Classification of genotypes using unweighted pair-group method using complete-linkage clustering led to six distinct groups. Some wild and cultivated varieties placed in the same groups. It seems there are close relationship between wild and cultivated genotypes and maybe wild genotypes are ancestor of native grapevines. Grouping of grapevine genotypes based on molecular marker data was not in agreement with clustering by agro-morphological data indicating that the most of multiplied sequences are confined to the non-coding regions of transposon elements. Results showed a substantial level of genetic diversity at molecular and pomological level and the potential of this diversity for future grape breeding programs.

Cobalt-induced retrotransposon polymorphism and humic acid protection on maize genome.

Retrotransposon activity and genomic template stability (GTS) are one of the most significant rearranging mechanisms in environmental stress. Therefore, in this study, it is aimed to elucidate effecting of Cobalt (Co) on the instability of genomes and Long Terminal Repeat retrotransposon polymorphism in Zea mays and whether humic acid (HA) has any role on these parameters. For this purpose, Retrotransposon-microsatellite amplified polymorphism (REMAP) and Inter-Retrotransposon Amplified Polymorphism (IRAP) markers were applied to evaluate retrotransposon polymorphism and the GTS levels. It was found that IRAP and REMAP primers generate unique polymorphic band structures on maize plants treated with various doses of Co. Retrotransposon polymorphism increased and GTS decreased while increasing Co concentration. On the other hand, there was a reduction in negative effects of Co on retrotransposon GTS and polymorphism after treatment with HA. The results indicate that HA may be used effectively for the protection of maize seedlings from the destructive effects of Co toxicity.

Assessment of Genetic Relationships among Cultivated and Wild Pistachios (Pistacia vera L.) using Molecular Markers

Abstract Iran is one of the main diversity centers and origins of pistachios in the world. Pistachio cultivation spread first within the ancient Persian Empire and then moved gradually westward. Knowledge of the genetic relationships among wild and cultivated varieties of pistachio is important for the efficient utilization of the available germplasm resources. Three molecular marker strategies, namely, inter-simple sequence repeat (ISSR), inter-retrotransposon amplified polymorphism (IRAP), and retrotransposon microsatellite amplified polymorphism (REMAP), were used to study the genetic relationships among 35 pistachio accessions including 15 wild-type genotypes of Pistacia vera and 20 important cultivars from Iran. According to the results, high levels of polymorphism were observed for all three marker systems. REMAP and IRAP techniques had the higher mean values of genetic relationships parameters than ISSR technique. The results from this study showed that the 5′LTR2, Sukkula, Sukkula + UBC855, and 5′LTR2 + UBC811 primers were the most informative and could be used to evaluate the genetic relationships of pistachios accessions. Cluster analysis using the unweighted pair group method with arithmetic mean (UPGMA) properly separated the accessions and divided them into four main groups. The presence of most cultivated genotypes in a group indicates genetic erosion of cultivated pistachio in Iran. Wild-type genotypes of P. vera are located in different clusters indicating the high diversity of the genotypes. The results provide useful genetic information about wild pistachios in northeastern of Iran and indicate that the use of wild pistachios in breeding programs could be useful for generating new genotypes with interesting characters.

Elucidate Genetic Diversity and Population Structure of Bread Wheat (Triticum Aestivum L.) Cultivars Using IRAP and REMAP Markers

Analysis of genetic diversity and population structure in bread wheat is an essential step in their conservation, utilization, and breeding. Retrotransposons are ubiquitous and abundant a throughout the plant genomes, therefore extensively used as ideal molecular markers for genetic variability, DNA fingerprinting and genetic mapping studies in plant species. In the current research, we used two retrotransposon-based marker systems, inter-retrotransposon amplified polymorphisms (IRAPs), and the retrotransposon-microsatellite amplified polymorphisms (REMAPs) markers to evaluate the genetic diversity and survey activity of long terminal repeat retrotransposon (LTR-retrotransposon) elements in a collection of 49 bread wheat (Triticum aestivum L.) cultivars that mainly bred in Iran. In general, 90 and 126 loci were amplified using 9 IRAP and 20 REMAP primers, respectively. Both techniques produced a satisfactory number of bands for cultivar analysis; however, the technique IRAP, particularly single primer Nikita generated a large number of bands, indicating the wide activity of Nikita family under various environmental conditions of bread wheat. The percentage of polymorphic loci (PPL) in the studied collection for IRAP and REMAP markers was 81.78 and 86.40%, respectively. A model-based Bayesian method, Principal coordinate analysis (PCoA) and cluster analysis using Minimum Evolution (ME) algorithm hinted of the existence of two groups. This grouping was in agreement with the growing season and conformed by the high within-group bootstrap value. These results demonstrated that these markers developed using transpositionally active retrotransposons (RTNs) are efficient and reliable markers in determining level of genetic diversity and population structure in bread wheat in breeding programs.

Genetic characterization of Moniliophthora perniciosa from Ecuador and in vitro sensitivity to compost tea

Moniliophthora perniciosa is the causal agent of the witches’ broom disease (WBD) in cacao but the morphological and molecular diversity of M. perniciosa in Ecuador—the top fine flavor cacao producer worldwide—are poorly understood and the pathogen’s sensitivity to compost teas is unknown. A total of 90 isolates of M. perniciosa were obtained from symptomatic samples of cocoa branches and pods collected from four cocoa-producing regions of Ecuador. Growth of each isolate was assed and fitted to a Gompertz model, and the molecular variability was evaluated by sequencing the ITS1, 5 .8s, and ITS2 rDNA regions as well as by inter-retrotransposon amplified polymorphism (IRAP), retrotransposon microsatellite amplified polymorphism (REMAP), and simple sequence repeats (SSR) analyses. Sensitivity of M. perniciosa to a compost tea was evaluated at concentrations of 0.5, 1, 1.5, 2, 2.75, and 3.5% in PDA. Results showed morphological and growth rate homogeneity across isolates. Mycelial growth fitted to Gompertz model gave similar parameter estimates for isolates from the different sampling sites. No molecular variability was observed based on ITS and SSR analysis but IRAP and REMAP tests showed high polymorphism. The total genetic diversity based on IRAP and REMAP tests was 0.28 and the genetic diversity within population was 0.24, with Nei’s diversity, Shannon’s Information, and percent polymorphism values of 0.315, 0.48, and 95.24, respectively for the whole sampled population; isolates from Los Rios province being the most polymorphic. Compost tea sensitivity analysis performed on 85 of the isolates showed a significant inhibitory effect at concentrations of 2.75% or above but concentrations below 1.5% significantly enhanced the growth of most isolates of the pathogen. Results confirmed the high genetic diversity of M. perniciosa and provided insights into growth rate and compost tea sensitivity of the pathogen in Ecuador.

Development and use of retrotransposons-based markers (IRAP/REMAP) to assess genetic divergence among table grape cultivars

AbstractFor more than four decades after the introduction of cv. Italia (Vitis vinifera L.) in Brazil, several somatic mutations in the genome of cv. Italia and its somatic mutants gave rise to phenotypes which generated at least five new cultivars of fine table grapes. Since no molecular marker proved to be effective in discriminating cv. Italia (V. vinifera L.) and its coloured mutants (Rubi, Benitaka, Brasil, Black Star), primers for the long terminal repeat (LTR) sequences were developed to analyse Inter Retrotransposon Amplified Polymorphism (IRAP) and Retrotransposon-Microsatellite Amplified Polymorphism (REMAP), and investigate how the coloured cultivars derived from clonal propagations of somatic mutations are genetically structured. Primers for LTR sequences of IRAP and REMAP markers were edited from grape sequence databases available at a GenBank. Twenty-four primers, denominated DKS001–DKS024, were edited. Three hundred and forty-nine DNA segments were amplified by individual DKS primers and DKS/ISSR (Inter Simple Sequence Repeats) primer combinations, at an average of 13.96 amplicons per primer pair. High genetic divergence between the five cultivars was inferred from polymorphism in retrotransposons IRAP and REMAP. The analysis of polymorphism of IRAP and REMAP retrotransposons was crucial to show that clonal propagation of somatic mutations may lead towards the formation of genetically divergent cultivars by the formation of genetically structured vineyards and show the mixture of genomes within each cultivar.

Molecular characterization of a diverse Iranian table grapevine germplasm using REMAP markers: population structure, linkage disequilibrium and association mapping of berry yield and quality traits

In this study forty-five table grape Iranian cultivars were assessed by using 42 retrotransposon-microsatellite amplified polymorphism (REMAP) markers also analyzing population structure, linkage disequilibrium and genomic regions associated with most important berry yield and quality traits. The phenotypic results showed the great diversity of the Iranian germplasm and their suitability for genetic and association studies. The studied grape cultivars were divided into three populations. A significant level of LD was observed in 1.22% of the retrotransposon marker pairs (P < 0.01). Mixed linear model procedure revealed that 40 loci had significant association with investigated traits. Finally, 27 markers showed significant association with regions controlling the studied berry yield and quality traits. These REMAP loci identified in this study associated to phenotypic traits may be applied in marker-assisted selection in table grape breeding programs.

IRAP and REMAP based genetic diversity among varieties of Lallemantia iberica.

This study describes the genetic relationships among 34 varieties of Lallemantia iberica using inter-retrotransposon amplified polymorphism (IRAP) and retrotransposon-microsatellite amplified polymorphism (REMAP). Samples were collected from Agriculture Research Center of Urmia city (northwest Iran). Ten IRAP and REMAP primers generated 76 scorable electrophoretic bands with 78.94% polymorphism. The pair-wise Jacquard genetic similarity varied from 0.48 to 0.94 for IRAP and REMAP data combined. Average PIC values for IRAP and REMAP markers were 0.38. The retro-elements marker system produced 76 alleles in range of 100- 3000 bp. The cophenetic correlation coefficient between Jaccard's similarity matrix and the plotted dendrogram was 0.66. A dendrogram constructed based on COMPLETE LINKAGE. Cluster analysis of IRAP and REMAP data using the NTSYSpc 2.02 resulted in five clusters. The present study represents high genetic distance at genotype level suggesting that IRAP and REMAP markers are useful for Lallemantia iberica genetic diversity analysis.

Identification of SSR and retrotransposon-based molecular markers linked to morphological characters in oily sunflower ( $$\textit{Helianthus annuus}$$ Helianthus annuus L.) under natural and water-limited states

Sunflower is an important source of edible oil. Drought is known as an important factor limiting the growth and productivity of field crops in most parts of the world. Agricultural biotechnology mainly aims at developing crops with higher tolerance to the challenging environmental conditions, such as drought. This study examined a number of morphological characters, along with relative water content (RWC) in 100 inbred sunflower lines. A 10 × 10 simple lattice design with two replications was employed to measure the mentioned parameters under natural and water-limited states during two successive years. In molecular trial, 30 simple sequence repeat (SSR) primer pairs, as well as 14 inter-retrotransposon amplified polymorphism (IRAP) and 14 retrotransposon-microsatellite amplified polymorphism (REMAP) primer combinations were used for DNA fingerprinting of the lines. Most of the examined characters had lower average values under water-limited than natural states. Maximum and minimum reductions were observed in the cases of yield and oil percentage, respectively. The broad-sense heritabilities for all the examined characters were 0.20-0.73 and 0.10-0.34 under natural and water-limited states, respectively. In the studied samples, 8.97% of the 435 possible locus pairs of the SSRs represented significant linkage disequilibrium (LD) levels. In the association analysis using SSR markers, 22 and 21 markers were identified (P ≤ 0.05) for the studied characters under natural and water-limited states, respectively. The corresponding values were 50 and 37 using retrotransposon-based molecular markers. Some detected markers were communal between the characters under water-limited and natural states. This was in line with the phenotypic correlations detected between the characters. Communal markers facilitate the simultaneous selection of several characters and can thus improve the efficacy of selection based on markers in the plant-breeding activities.

Analysis of genetic diversity in pigeon pea germplasm using retrotransposon-based molecular markers.

Pigeon pea (Cajanus cajan), an important legume crop is predominantly cultivated in tropical and subtropical regions of Asia and Africa. It is normally considered to have a low degree of genetic diversity, an impediment in undertaking crop improvement programmes.We have analysed genetic polymorphism of domesticated pigeon pea germplasm (47 accessions) across the world using earlier characterized panzee retrotransposon-based molecularmarkers. Itwas conjectured that since retrotransposons are interspersed throughout the genome, retroelements-based markers would be able to uncover polymorphism possibly inherent in the diversity of retroelement sequences. Two PCR-based techniques, sequence-specific amplified polymorphism (SSAP) and retrotransposon microsatellite amplified polymorphism (REMAP) were utilized for the analyses.We show that a considerable degree of polymorphism could be detected using these techniques. Three primer combinations in SSAP generated 297 amplified products across 47 accessions with an average of 99 amplicons per assay. Degree of polymorphism varied from 84-95%. In the REMAP assays, the number of amplicons was much less but up to 73% polymorphism could be detected. On the basis of similarity coefficients, dendrograms were constructed. The results demonstrate that the retrotransposon-based markers could serve as a better alternative for the assessment of genetic diversity in crops with apparent low genetic base.

RETRACTED ARTICLE: Comparison of traditional and new generation DNA markers declares high genetic diversity and differentiated population structure of wild almond species

Wild almond species as sources of genetic variation may have crucial importance in breeding. A total of 389 accessions of 18 species have been analysed using inter-retrotransposon amplified polymorphism (IRAP), retrotransposon-microsatellite amplified polymorphism (REMAP), sequence-specific amplification polymorphism (S-SAP), amplified fragment length polymorphism (AFLP), inter simple sequence repeat (ISSR) and simple sequence repeats (SSR). Retrotransposon markers indicated the presence and movement of some Ty3-gypsy and Ty1-copia-elements in almond genome. Since transposable elements are associated with large-scale genome alterations, REMAP produced more reliable phylogenetic inferences than AFLP where homoplasy may affect clustering. In addition, high resolution melting (HRM) analysis was developed to detect SNPs. HRM analysis revealed 1:189 bp frequency of SNPs in exon positions, and the transition-to-transversion proportion was 1.84:1. The low transition bias suggests low methylation levels in almond genome. The polymorphic information content (PIC) was the highest for SSR markers, while SNPs had an average PIC of 0.59, which is close to the values of the rest of the markers. Huge genetic diversity, fragmented population structure and footprints of human selection was confirmed by merging information from all marker strategies. Considering time, cost and performance HRM can be a marker of choice in future studies of Prunus diversity.

Molecular Diversity in some Ghanaian Cowpea [Vigna unguiculata L. (Walp)] Accessions

Cowpea [Vigna unguiculata L. (Walp)] is grown mainly for its protein-rich grains and is consumed in various forms in sub-Saharan Africa. Average grain yield in farmers’ fields is generally low due to a number of biotic and abiotic stresses. One hundred and six cowpea accessions from Ghana, which had previously been evaluated for seedling drought tolerance, were used for this study. This paper attempts to use three multi-locus PCR-based molecular markers; simple sequence repeats (SSR), inter-retrotransposon amplified polymorphism (IRAP) and retrotransposon-microsatellite amplified polymorphisms (REMAP), to analyse genetic diversity in the cowpea accessions. Analysis of the polymorphic bands data indicated that 101 alleles were amplified among 121 cowpea genotypes (83.4%) from 16 SSR primer pairs out of a total of 30 SSR primer pairs. Likewisely, a total of 66 (54.5%) polymorphic bands were obtained from IRAP and a total of 114 (94.2%) highly polymorphic bands obtained from REMAP analysis. The outcome indicated the highly polymorphic nature of the DNA markers, as small groups of these molecular markers were found to be able to identify each of the accessions used. Microsatellite markers (SSRs) and retrotransposon-based markers, like IRAP and REMAP, were found to be highly polymorphic and informative, suggesting that genomic fingerprinting has a major role in characterizing populations.

Transposon-based genetic diversity assessment in wild and cultivated barley

Transposable element-based molecular markers can be utilized to investigate genetic diversity and to create genetic linkage maps. In this study, Class I and class II transposons were employed to obtain a comparative account of genetic diversity between wild and cultivated barley genotypes. Three types of PCR-based techniques were used: IMP (Inter MITE Polymorphism), IRAP (Inter-Retrotransposon Amplified Polymorphism) and REMAP (Retrotransposon-Microsatellite Amplified Polymorphism). Specific primer pairs for IMP, IRAP, and REMAP detected a total of 200 bands with an average of 20 bands per marker. The mean polymorphic information content (PIC) and discrimination power (D) values in all 47 genotypes from these three types of transposon-based polymorphisms were 0.910 and 0.935, respectively. Unweighted Pair Group Method with Arithmetic mean (UPGMA)-based cluster analysis classified all 47 genotypes, both wild and cultivated, into separate groups consistent with their geographical origins. Sequencing followed by chromosome location of polymorphic bands enables precise gene introgression from wild gene pool to cultivated barley. The highly polymorphic nature of these marker systems makes them suitable for use in varietal identification and MAS-based breeding programs in barley and other cereals.

Patterns of Evolutionary Trajectories and Domestication History within the Genus Hordeum Assessed by REMAP Markers.

The patterns of genetic diversity related to the taxonomy and domestication history of 85 accessions representing the main four species of the genus Hordeum were examined by retrotransposon-microsatellite amplified polymorphism (REMAP) markers based on the retrotransposon BARE-1. A substantial level of genetic polymorphisms at among- and within-species level was observed showing that this retrotransposon family and its adjacent genomic regions has been a target for genome dynamics during the evolution and domestication of barley. The obtained data are consistent with the current taxonomic status within the genus Hordeum. Similar level of genetic diversity was observed between the wild and the domesticated barley accessions suggesting that transposable elements` activity and accumulation may counteract the decrease of genome-wide diversity following domestication. In addition, eco-geographical sub-genome pools of the cultivated barley were identified in support to the theory of multiple origins of domestication within the genus Hordeum. We also provide conclusions about the relationship between accessions of different species and the putative routes of barley domestication. In conclusion, the retrotransposon BARE-1 stands as a reliable and perspective DNA marker for the assessment of the phylogenetic and domestication history in the genus Hordeum and other crop species.

Using Two Retrotransposon Based Marker Systems (IRAP and REMAP) for Molecular Characterization of Olive (&lt;i&gt;Olea europaea&lt;/i&gt; L.) Cultivars

Olive (Olea europaea L.) is one of the most characteristic agricultural trees of the Mediterranean region and has a large number of cultivar diversity. Olive cultivar characterization is very important especially for the fruit productivity and olive oil quality. In the present study, 46 clones belonging to Turkey (eight cultivars, each having five clones) and Italy (two cultivars, each having three clones) were assessed for cultivar characterization via inter-retrotransposon amplified polymorphism (IRAP) and retrotransposon-microsatellite amplified polymorphism (REMAP) marker systems using 10 LTR and 10 ISSR primers. In total, 368 band profiles were obtained, 358 of which are polymorphic (97.28% polymorphism). The cultivars were segregated into three main groups, each group having several branches, where all the clones of each cultivar were belonging to the same main group. The only exception to that was the distribution of the clones of cultivar Yaglik, 'Yaglik 4' and 'Yaglik 5', into different main groups. IRAP and REMAP analysis showed a high level of genetic variability among the olive cultivars in this study and this marker systems would be useful tool for clonal selection programs.