Simple sequence repeats for germplasm analysis and mapping in maize

Genome ◽  
1996 ◽  
Vol 39 (2) ◽  
pp. 277-287 ◽  
Author(s):  
Graziana Taramino ◽  
Scott Tingey
Keyword(s):  
Ssr Markers ◽  
Simple Sequence Repeats ◽  
Trinucleotide Repeats ◽  
High Rate ◽  
Rflp Markers ◽  
Sequence Motifs ◽  
Genomic Libraries ◽  
Expected Heterozygosity ◽  
Germplasm Analysis ◽  
Simple Sequence

Simple sequence repeats (SSRs) are a relatively new class of DNA markers consisting of short runs of tandemly repeated sequence motifs evenly distributed throughout eukaryotic genomes. Owing to the high rate of variation in the number of repeat units, the polymorphism level shown by SSRs is high. Furthermore, they are easy to analyze by means of the polymerase chain reaction, using flanking unique sequence primers. In order to establish the utility of SSR markers for genetic mapping and for the analysis of corn germplasm, corn genomic libraries were constructed and screened for clones containing dinucleotide and trinucleotide repeats. One hundred and fifty clones were isolated and 34 of them were used in this study to analyze 15 (AG)n repeats, 15 (AC)n repeats, and 4 trinucleotide repeats. Twelve corn inbred lines, representing 87% of the RFLP alleles present in a collection of public corn cultivars, were used to assess the information content of the SSR markers. The expected heterozygosity of each SSR marker was compared with the expected heterozygosity of 100 different RFLP markers. The stability of SSRs was also tested through segregation analysis on an existing mapping population. Key words : simple sequence repeats, microsatellites, maize, germplasm analysis, mapping.

Development of simple sequence repeat markers in rye (Secale cereale L.)

Genome ◽  
1999 ◽  
Vol 42 (5) ◽  
pp. 964-972 ◽  
Author(s):  
B Saal ◽  
Günter Wricke
Keyword(s):  
Ssr Markers ◽  
Secale Cereale ◽  
Simple Sequence Repeats ◽  
Rflp Markers ◽  
Dinucleotide Repeats ◽  
Genomic Libraries ◽  
Allele Number ◽  
Expected Heterozygosity ◽  
Secale Cereale L ◽  
Simple Sequence

Simple sequence repeats (SSRs), also referred to as microsatellites, represent a PCR-based marker system that has been described in mammalian and plant genomes in recent years. In self-pollinating crop plants they have been shown to be superior to other DNA markers with respect to their level of polymorphism. The technical advantages compared with RFLP markers should also facilitate marker analysis in outcrossing crops like rye. In order to determine the usefulness of SSR markers in rye genetics and breeding, several genomic libraries were screened for (CT/GA)n and (GT/CA)n dinucleotide repeats. It was estimated that these motifs occur at a frequency of one per 268-519 kb. Seventy four out of 182 positive clones were sequenced, and the majority (56.8%) revealed perfect repeats, predominantly of the type (GT/CA)n (61.9%). Fifty seven primer pairs were designed and 27 (47.4%) resulted in specific SSR markers, of which 20 were genetically mapped or assigned to chromosomes or chromosome arms, respectively. The level of polymorphism of four SSR and three RFLP markers was assessed in two open-pollinated rye cultivars. On average, the SSR markers showed larger values of expected heterozygosity (0.62 vs. 0.43) and allele number (5.9 vs. 3.4) than RFLP markers in both cultivars.Key words: simple sequence repeats, microsatellites, mapping, rye, Secale cereale.

Genetic mapping and variability of seven soybean simple sequence repeat loci

Genome ◽  
1994 ◽  
Vol 37 (5) ◽  
pp. 763-769 ◽  
Author(s):  
M. Morgante ◽  
A. Rafalski ◽  
P. Biddle ◽  
S. Tingey ◽  
A. M. Olivieri
Keyword(s):  
Simple Sequence Repeats ◽  
Simple Sequence Repeat ◽  
Allelic Variation ◽  
Glycine Soja ◽  
Wild Soybean ◽  
Rflp Markers ◽  
Sequence Motifs ◽  
Sequence Repeat ◽  
Rflp Map ◽  
Simple Sequence

Microsatellites or simple sequence repeats are stretches of short tandemly repeated DNA sequence motifs, dispersed throughout the genomes of most eukaryotes. Simple sequence repeat polymorphisms (SSRPs) have recently been reported in plants. Here we present the genetic map position of seven different soybean (Glycine max (L.) Merr. and Glycine soja Sieb. and Zucc.) SSRPs contained in sequenced genes, four of which represent newly mapped positions for these genes. The other three SSRPs coincided with independently established RFLP map positions for the corresponding genes. When a set of 61 soybean accessions was screened at four of these loci by using agarose gels, the average number of alleles per locus was 7.75, the effective number of alleles (ne) was 2.57, and the level of allele differentiation (δT) was 0.62. Allelic variation decreased sharply with increasing levels of domestication, with the level of differentiation going from 84% in the wild soybean to 43% in the elite germplasm. Variation levels observed on a subset made of 19 of the 61 lines were always higher for SSRPs than for RFLP markers, with the average number of alleles per locus going from 4.25 to 2.15. In comparison with RFLP markers, SSRPs are more informative and are easier to analyse but require more effort to develop.Key words: simple sequence repeats, soybean, variability, mapping, domestication, microsatellites.

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.

Molecular characterization of almond accessions from the island of La Palma (Canary Islands, Spain) using SSR markers

2014 ◽  
Vol 12 (3) ◽  
pp. 323-329 ◽  
Author(s):  
Guillermo Padilla ◽  
Rafel Socias i Company ◽  
Amando Ordás
Keyword(s):  
Genetic Diversity ◽  
Ssr Markers ◽  
Average Value ◽  
La Palma ◽  
Expected Heterozygosity ◽  
Commercial Cultivars ◽  
Soft Shell ◽  
Genetic Profiles ◽  
Simple Sequence

In this study, 15 simple sequence repeat (SSR) markers were used for genetic diversity analysis of 45 almond accessions, which included 25 local cultivars from La Palma Island and three other commercial cultivars. A total of 110 amplification fragments were produced, with an average value of 7.9 alleles per locus. Twelve of the SSR markers can be considered as highly informative, with values of expected heterozygosity and power of discrimination above 0.5 and 0.8, respectively. Due to cases of synonymy and homonymy, 37 different genetic profiles were obtained, with the homonymy of the soft-shell varieties known as ‘Mollar’ being the most significant. Cluster analysis identified four groups within the accessions. One of these groups exclusively consisted of the two commercial cultivars ‘Guara’ and ‘Ferraduel’. The other commercial cultivar used in the study, ‘Desmayo Largueta’, was in a cluster with three cultivars from the same locality. The analysis of molecular variance revealed that the within-localities component accounts for most of the total variation, suggesting that La Palma almond cultivars did not originate independently in different parts of the island. The results of the study reveal the genetic singularity of La Palma almond cultivars and the genetic diversity among them.

scholarly journals Cross-transferability-based identification and validation of simple sequence repeat (SSR) markers in oaks of western Himalayas

2021 ◽  
Vol 70 (1) ◽  
pp. 108-116
Author(s):  
Chander Shekhar ◽  
Anita Rawat ◽  
Maneesh S. Bhandari ◽  
Santan Barthwal ◽  
Harish S. Ginwal ◽  
...  
Keyword(s):  
Ssr Markers ◽  
Gene Diversity ◽  
Cost Effective ◽  
Sequence Information ◽  
Western Himalayas ◽  
Population Genetic Analysis ◽  
Expected Heterozygosity ◽  
Cost Effective Method ◽  
Quercus Semecarpifolia ◽  
Simple Sequence

Abstract Cross-amplification is a cost-effective method to extend the applicability of SSR markers to closely related taxa which lack their own sequence information. In the present study, 35 SSR markers developed in four oak species of Europe, North America and Asia were selected and screened in five species of the western Himalayas. Fifteen markers were successfully amplified in Quercus semecarpifolia, followed by 11 each in Q. floribunda and Q. leucotrichophora, 10 in Q. glauca, and 9 in Q. lana-ta. Except two primer pairs in Q. semecarpifolia, all were found to be polymorphic. Most of the positively cross-amplified SSRs were derived from the Asian oak, Q. mongolica. The genoty-ping of 10 individuals of each species with positively cross-amplified SSRs displayed varied levels of polymorphism in the five target oak species, viz., QmC00419 was most polymorphic in Q. floribunda, QmC00716 in Q. glauca and Q. lanata, QmC01368 in Q. leucotrichophora, and QmC02269 in Q. semecarpifolia. Among five oak species, the highest gene diversity was depicted in Q. lanata and Q. semecarpifolia with expected heterozygosity (He = 0.72), while the minimum was recorded for Q. leucotrichophora and Q. glauca (He = 0.65). The SSRs validated here provide a valuable resource to carry out further population genetic analysis in oaks of the western Himalayas.

scholarly journals Assessment of Genetic Relationship among Male and Female Fig Genotypes Using Simple Sequence Repeat (SSR) Markers

2017 ◽  
Vol 45 (1) ◽  
pp. 172-178
Author(s):  
Sevin TEOMAN ◽  
Meryem IPEK ◽  
Umran ERTURK ◽  
Nesrin Aktepe TANGU ◽  
Erdem DURGUT ◽  
...  
Keyword(s):  
Ssr Markers ◽  
Genetic Relationship ◽  
Simple Sequence Repeat ◽  
Ssr Marker ◽  
Aegean Sea ◽  
Gene Pools ◽  
Sequence Repeat ◽  
Expected Heterozygosity ◽  
Male Tree ◽  
Simple Sequence

Fig (Ficus carica L.) is a traditional crop in Turkey and widely cultivated around the Mediterranean areas. The gynodioecious fig species is present in two sexual forms, i.e. the domesticated fig (female tree) and the caprifig (male tree). Caprifigs are crucial for high quality fig production and breeding while, the studies on assessment of genetic relationship among caprifigs is limited. The aim of this study was to determine genetic diversity among 45 caprifigs and 2 female figs collected from four provinces in Marmara and Aegean Sea Regions of Turkey using simple sequence repeat (SSR) markers. In this work, 24 SSR markers were tested, one was monomorphic and the remaining markers amplified 82 alleles. The number of polymorphic alleles per SSR marker ranged from 2 to 7. The observed heterozygosity (Ho) differed from 0.18 to 0.76 and expected heterozygosity (He) ranged between 0.24 and 0.81. The polymorphism information content (PIC) varied from 0.42 to 0.98. A UPGMA analysis based on Dice similarity matrix clustered fig genotypes into two main groups and similarly, STRUCTURE analysis placed fig genotypes into two different gene pools (K=2). Fig genotypes collected from the same region were not clustered together in a group indicating that the fig genotypes did not cluster on the basis of their collection sites. Our results demonstrated that caprifigs and female figs are not genetically distinct and they clustered together in a group. All fig genotypes had distinct SSR marker profiles suggesting that there were no synonyms or homonyms. These results revealed a high genetic variation among fig genotypes and 23 SSR markers were enough to discriminate all fig genotypes analysed in this study demonstrating that SSR marker system is suitable for genetic analysis in figs.

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