scholarly journals Genetic and Physical Mapping of Genic Microsatellites in Barley (Hordeum vulgare L.)

2011 ◽  
Vol 41 (No. 4) ◽  
pp. 153-159
Author(s):  
R.K. Varshney ◽  
U. Hähnel ◽  
T. Thiel ◽  
N. Stein ◽  
L. Altschmied ◽  
...  
Keyword(s):  
Large Scale ◽  
Expressed Sequence Tag ◽  
Sequence Data ◽  
Bac Library ◽  
Linkage Groups ◽  
Hordeum Vulgare L ◽  
Expressed Sequence ◽  
Simple Sequence ◽  
Mapping Populations ◽  
Genic Microsatellites

Due to the availability of sequence data from large-scale EST (expressed sequence tag) projects, it has become feasible to develop microsatellite or simple sequence repeat (SSR) markers from genes. A set of 111 090 barley ESTs (corresponding to 55.9 Mb of sequence) was employed for the identification of microsatellites with the help of a PERL5 script called MISA. As a result, a total of 9 564 microsatellites were identified in 8 766 ESTs (SSR-ESTs). Cluster analysis revealed the presence of 2 823 non-redundant SSR-ESTs in this set. From these 754 primer pairs were designed and analysed in a set of seven genotypes including the parents of three mapping populations. Finally, 185 microsatellite (EST-SSRs) loci were placed onto the barley genetic map. These markers show a uniform distribution on all the linkage groups ranging from 21 markers (on 7H) to 35 markers (3H). The polymorphism information content (PIC) for the developed markers ranged from 0.24 to 0.78 with an average of 0.48. For the assignment of these markers to BAC clones, a PCR-based strategy was established to screen the “Morex”-BAC library. By using this strategy BAC addresses were obtained for a total of 127 mapped EST-SSRs, which may provide at least two markers located on a single BAC. This observation is indicative of an uneven distribution of genes and may lead to the identification of gene-rich regions in the barley genome.  

Characterization of expressed sequence tag-derived simple sequence repeat markers for 17 Linum species

Botany ◽  
2010 ◽  
Vol 88 (5) ◽  
pp. 537-543 ◽  
Author(s):  
Yong-Bi Fu ◽  
Gregory W. Peterson
Keyword(s):  
Simple Sequence Repeat ◽  
Expressed Sequence Tag ◽  
Sequence Repeat ◽  
Simple Sequence Repeat Markers ◽  
Linum Usitatissimum L ◽  
Evolutionary Studies ◽  
Expressed Sequence ◽  
Simple Sequence ◽  
Cultivated Flax

One major challenge in genetic and evolutionary studies of wild flax species is the lack of informative molecular markers. A set of 100 informative expressed sequence tag-derived simple sequence repeat (EST-SSR) primer pairs developed in cultivated flax ( Linum usitatissimum L.) were characterized on 35 Linum accessions representing 17 Linum species for their transferability to other Linum species. Ninety-nine primer pairs displayed scorable polymorphisms across 35 Linum samples and generated 627 bands likely from 121 loci. About 50% of the detected bands occurred only in three or fewer samples. A total of 393 bands, likely from 116 loci, were detected by 97 primer pairs in Linum bienne Mill. samples, but only up to 60 bands, likely from up to 39 loci, were revealed by 6 to 37 primer pairs in the samples of the other 15 Linum species. The L. bienne samples displayed 23.7% more EST-SSR variation than the L. usitatissimum samples. These characterized EST-SSR markers should be useful for future genetic diversity and evolutionary studies of Linum species, particularly for the progenitor of cultivated flax.

scholarly journals Development of EST-derived SSR Markers with Long-core Repeat in Olive and Their Use for Paternity Testing

2013 ◽  
Vol 138 (4) ◽  
pp. 290-296 ◽  
Author(s):  
Raúl De la Rosa ◽  
Angjelina Belaj ◽  
Antonio Muñoz-Mérida ◽  
Oswaldo Trelles ◽  
Inmaculada Ortíz-Martín ◽  
...  
Keyword(s):  
Ssr Markers ◽  
Simple Sequence Repeats ◽  
Expressed Sequence Tag ◽  
Paternity Testing ◽  
High Level ◽  
Repeated Motifs ◽  
Expressed Sequence ◽  
Simple Sequence ◽  
Olive Breeding ◽  
Genomic Project

In the present work, a set of eight new hexa-nucleotide simple sequence repeats (SSRs) is reported in olive (Olea europaea L). These SSRs loci were generated on the basis of expressed sequence tag (EST) sequences in the frame of an olive genomic project. The markers showed a high level of polymorphism when tested on a set of cultivars used as genitors in the olive breeding program of Córdoba, Spain. The long-core repeat motif of these markers allows a wider separation among alleles, thus permitting an accurate genotyping. Besides, these markers showed comparable levels of polymorphism to di-nucleotide SSRs, the only ones so far reported in olive. Selected on the basis of their discrimination capacity, four of the eight SSRs were used to test their ability for paternity testing in a total of 81 seedlings coming from 12 crosses. The paternity testing showed that seven crosses matched the alleged paternity and the remaining five were products of illicit pollinations. These results exactly matched with previous paternity testing performed with di-nucleotide SSR markers. These results demonstrate the usefulness of the developed hexa-nucleotide repeated motifs for checking the paternity of breeding progenies and suggest their use on variability studies.

scholarly journals Does the genetic diversity among pubescent white oaks in southern Italy, Sicily and Sardinia islands support the current taxonomic classification?

2020 ◽  
Author(s):  
Romeo Di Pietro ◽  
Antonio Luca Conte ◽  
Piera Di Marzio ◽  
Paola Fortini ◽  
Emmanuele Farris ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Expressed Sequence Tag ◽  
Taxonomic Classification ◽  
Genetic Assignment ◽  
Molecular Analyses ◽  
Genetic Groups ◽  
Ecological Features ◽  
Weak Separation ◽  
Expressed Sequence ◽  
Simple Sequence

AbstractMolecular diversity analysis of deciduous pubescent oaks was conducted for populations from Calabria, Sicily and Sardinia. The aims of this study were twofold. First, to provide data on the genetic diversity of pubescent oaks from an understudied area which currently exhibits one of the highest concentrations of pubescent oak species in Europe. Second, to verify if these groups of oaks are genetically distinct and if their identification is in accordance with the current taxonomic classification. Molecular analyses of leaf material of 480 trees from seventeen populations belonging to putatively different pubescent oak species (Quercus amplifolia, Q. congesta, Q. dalechampii, Q. ichnusae, Q. leptobalanos, Q. virgiliana) were performed. Twelve gene-based Expressed Sequence Tag-Simple Sequence Repeat markers were selected, and genetic diversity and differentiation were calculated. The results showed relatively high values of allelic richness, heterozygosity and number of private alleles for the populations investigated. A weak but positive correlation between geographical and genetic distance was detected. Genetic assignment (STRUCTURE) and principle coordinate analyses exhibited a weak separation into two genetic groups which, however, did not correspond to the taxonomic, chorological and ecological features of the populations investigated. Sardinian populations formed one group which was separated from the Calabrian and Sicilian populations. In light of the results obtained, the taxonomic classification for the pubescent white oaks currently reported in the major Italian floras and checklists for the study area was not confirmed by molecular analyses.

Development and characterization of microsatellite markers from tropical forage Stylosanthes species and analysis of genetic variability and cross-species transferability

Genome ◽  
2011 ◽  
Vol 54 (12) ◽  
pp. 1016-1028 ◽  
Author(s):  
Amaresh Chandra ◽  
K.K. Tiwari ◽  
D. Nagaich ◽  
N. Dubey ◽  
S. Kumar ◽  
...  
Keyword(s):  
Genetic Improvement ◽  
Expressed Sequence Tag ◽  
Intraspecific Diversity ◽  
Genomic Libraries ◽  
Tropical Forage ◽  
Genomic Ssr ◽  
Functional Molecular Markers ◽  
Expressed Sequence ◽  
Simple Sequence

A limited number of functional molecular markers has slowed the desired genetic improvement of Stylosanthes species. Hence, in an attempt to develop simple sequence repeat (SSR) markers, genomic libraries from Stylosanthes seabrana B.L. Maass & ’t Mannetje (2n = 2x = 20) using 5′ anchored degenerate microsatellite primers were constructed. Of the 76 new microsatellites, 21 functional primer pairs were designed. Because of the small number of primer pairs designed, 428 expressed sequence tag (EST) sequences from seven Stylosanthes species were also examined for SSR detection. Approximately 10% of sequences delivered functional primer pairs, and after redundancy elimination, 57 microsatellite repeats were selected. Tetranucleotides followed by trinucleotides were the major repeated sequences in Stylosanthes ESTs. In total, a robust set of 21 genomic–SSR (gSSR) and 20 EST–SSR (eSSR) markers were developed. These markers were analyzed for intraspecific diversity within 20 S. seabrana accessions and for their cross-species transferability. Mean expected (He) and observed (Ho) heterozygosity values with gSSR markers were 0.64 and 0.372, respectively, whereas with eSSR markers these were 0.297 and 0.214, respectively. Dendrograms having moderate bootstrap value (23%–94%) were able to distinguish all accessions of S. seabrana with gSSR markers, whereas eSSR markers showed 100% similarities between few accessions. The set of 21 gSSRs, from S. seabrana, and 20 eSSRs, from selected Stylosanthes species, with their high cross-species transferability (45% with gSSRs, 86% with eSSRs) will facilitate genetic improvement of Stylosanthes species globally.

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