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

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.

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ANALISIS KERAGAMAN GENETIK PLASMA NUTFAH KAKAO (Theobroma cacaoL.) BERDASARKANMARKA SSR / Analysis of Genetic Variability Germplasm of Cacao (Theobroma cacaoL.)Basedon SSR Marker

Jurnal Penelitian Tanaman Industri ◽

10.21082/jlittri.v17n4.2011.156-162 ◽

2020 ◽

Vol 17 (4) ◽

pp. 156

Author(s):

Surti Kurniasih ◽

Rubiyo Rubiyo ◽

Asep Setiawan ◽

Agus Purwantara ◽

Sudarsono Sudarsono

Keyword(s):

Genetic Diversity ◽

Genetic Distance ◽

Ssr Markers ◽

Theobroma Cacao ◽

Simple Sequence Repeat ◽

Ssr Marker ◽

Gene Diversity ◽

Sequence Repeat ◽

Theobroma Cacao L ◽

Simple Sequence

Microsatellite or simple sequence repeat (SSR) markers have proven to be an excellent tool for cultivar identification, pedigree analysis, and genetic distance evaluations among organisms. The objectives of this research were to characterize cacao collection of Indonesian Coffee and Cacao Research Institute (ICCRI) and to analyze their genetic diversity using SSR markers. In this research, 39 SSR primer pairs were used to amplify genomic DNA of 29 cacao clones. Amplified SSR fragments for each primer pair were scored as individual band and used to determine genetic distance among evaluated cacao clones. Results of the experiment indicated that all SSR primer pairs evaluated were able to produce SSR markers for 29 cacao clones. The results also indicated that 34 out of 39 microsatellite loci evaluated were polymorphic, while 5 others were monomorphic. The total number of observed alleles among 29 clones was 132. Number of alleles per locus ranged from 4-8, with an average of 5.5 alelles per locus. Results of data analysis indicated that the PIC value was 0.665, the observed heterozigosity (Ho) was 0.651, and the gene diversity (He) was 0.720. The PIC, Ho, and He values were considered high. Genetic distances were evaluated using NTSys version 2.1 and dendrogram was constructed. Results of analysis indicated that 12 cacao clones evaluated were clustered in the first group with diversity coefficient of < 3.75. Nine cacao clones were in the second group but with the same value of diversity coefficient (<7.50). The rest of the cacao clones were in the third group with diversity coefficient of>7.50. Based on those finding, all SSR primer pairs evaluated could be used to analyze cacao genome and be useful for genetic diversity analysis of cacao germplasm. The SSR marker analysis in ICCRI cacao collections resulted in high PIC, high observed heterozygosity, and high genetic diversity.Key words: Theobroma cacao L, microsatelite, molecular marker, genetic diversity, heterozygosity AbstrakMarka mikrosatelit atau sekuens sederhana berulang (simple sequence repeat = SSR) terbukti merupakan alat yang bagus untuk identifikasi kultivar, analisis pedigree, dan evaluasi jarak genetik berbagai organisme. Penelitian ini bertujuan untuk:1) karakterisasi kakao koleksi Pusat penelitian Kopi dan Kakao Indonesia menggunakan marka SSR dan 2) analisis keragaman genetik klon-klon kakao koleksi dengan menggunakan marka SSR. Dalam penelitian ini, 39 pasangan primer SSR telah digunakan untuk amplifikasi DNA genomik dari 29 klon kakao. Skoring pita SSR hasil amplifikasi menggunakan masing-masing pasangan primer dilakukan secara terpisah dan digunakan untuk menentukan jarak genetik di antara klon kakao yang dievaluasi. Hasil percobaan menunjukkan bahwa semua pasangan primer SSR yang digunakan mampu menghasilkan pita DNA hasil amplifikasi (marka SSR) untuk 29 klon kakao yang diuji. Hasil penelitian juga menunjukkan bahwa 34 dari 39 lokus SSR yang dianalisis bersifat polimorfik sedangkan lima primer yang lain bersifat monomorfik. Dari 29 klon kakao yang dievaluasi, telah berhasil diamplifikasi sebanyak 132 alel, dengan kisaran antara 4-8 alel/lokus. Rataan jumlah alel per lokus sebanyak 5,50. Hasil analisis data yang dilakukan juga menunjukkan nilai PIC untuk marka SSR yang digunakan sebesar 0,665. Untuk populasi klon kakao yang dievaluasi, diperoleh nilai rataan heterosigositas pengamatan (Ho) sebesar 0,651 dan rataan diversitas gen (He) sebesar 0,720. Nilai PIC Ho dan He yang didapat tergolong tinggi. Berdasarkan analisis keragaman dengan menggunakan program NTSys, diperoleh hasil 12 klon kakao berada dalam grup pertama (koefisien keragaman<3,75) dan9 klon berada dalam grup kedua, dengan koefisien keragaman < 7,50. Sedangkan klon-klon lainnya mempunyai koefisien keragaman > 7,50. Berdasarkan hasil penelitian dan analisis data disimpulkan bahwa marka SSR dapat digunakan untuk menganalisis keragaman genetik plasma nutfah kakao. Tingkat polimorfisme yang dihasilkan marka SSR relatif tinggi. Tingkat heterosigositas plasma nutfah kakao koleksi Puslit Kopi dan Kakao Indonesiarelatif tinggi, dan keragaman genetiknyacukup tinggi.Kata kunci : Theobroma cacao L, mikrosatelit, marka molekuler, keragaman genetik, heterosigositas

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

Plant Genetic Resources ◽

10.1017/s1479262114000112 ◽

2014 ◽

Vol 12 (3) ◽

pp. 323-329 ◽

Cited By ~ 1

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.

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Novel Expressed Sequence Tag-Derived and Other Genomic Simple Sequence Repeat Markers Revealed Genetic Diversity in Ethiopian Finger Millet Landrace Populations and Cultivars

Frontiers in Plant Science ◽

10.3389/fpls.2021.735610 ◽

2021 ◽

Vol 12 ◽

Author(s):

Haftom Brhane ◽

Teklehaimanot Haileselassie ◽

Kassahun Tesfaye ◽

Cecilia Hammenhag ◽

Rodomiro Ortiz ◽

...

Keyword(s):

Genetic Diversity ◽

Ssr Markers ◽

Simple Sequence Repeat ◽

Finger Millet ◽

Expressed Sequence Tag ◽

Gene Diversity ◽

Geographic Regions ◽

Landrace Accessions ◽

Expressed Sequence ◽

Simple Sequence

Finger millet (Eleusine coracana (L.) Geartn.) is a self-pollinating amphidiploid crop cultivated with minimal input for food and feed, as well as a source of income for small-scale farmers. To efficiently assess its genetic diversity for conservation and use in breeding programs, polymorphic DNA markers that represent its complex tetraploid genome have to be developed and used. In this study, 13 new expressed sequence tag-derived simple sequence repeat (EST-SSR) markers were developed based on publicly available finger millet ESTs. Using 10 polymorphic SSR markers (3 genomic and 7 novel EST-derived), the genetic diversity of 55 landrace accessions and 5 cultivars of finger millet representing its major growing areas in Ethiopia was assessed. In total, 26 alleles were detected across the 10 loci, and the average observed number of alleles per locus was 5.6. The polymorphic information content (PIC) of the loci ranged from 0.045 (Elco-48) to 0.71 (UGEP-66). The level of genetic diversity did not differ much between the accessions with the mean gene diversity estimates ranging only from 0.44 (accession 216054) to 0.68 (accession 237443). Similarly, a narrow range of variation was recorded at the level of regional states ranging from 0.54 (Oromia) to 0.59 (Amhara and Tigray). Interestingly, the average gene diversity of the landrace accessions (0.57) was similar to that of the cultivars (0.58). The analysis of molecular variance (AMOVA) revealed significant genetic variation both within and among accessions. The variation among the accessions accounted for 18.8% of the total variation (FST = 0.19; P < 0.001). Similarly, significant genetic variation was obtained among the geographic regions, accounting for 6.9% of the total variation (P < 0.001). The results of the cluster, principal coordinate, and population structure analyses suggest a poor correlation between the genetic makeups of finger millet landrace populations and their geographic regions of origin, which in turn suggests strong gene flow between populations within and across geographic regions. This study contributed novel EST-SSR markers for their various applications, and those that were monomorphic should be tested in more diverse finger millet genetic resources.

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

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha45110756 ◽

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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Trait Phenotyping and Genic/Random SSR Markers Characterization for Breeding Early Maturing Wheat’s for Western-Himalayas

10.21203/rs.3.rs-217390/v1 ◽

2021 ◽

Author(s):

Safoora Shafi ◽

Mohd Tahir ◽

Mohd Anwar Khan ◽

Mohd Ashraf Bhat ◽

Uttam Kumar ◽

...

Keyword(s):

Ssr Markers ◽

Gene Diversity ◽

Allelic Diversity ◽

Separate Analysis ◽

Western Himalayas ◽

Single Marker Analysis ◽

Early Maturity ◽

Wheat Genotypes ◽

Early Maturing ◽

Improvement Programs

Abstract The study involves evaluation of 96 wheat genotypes for early maturity and related traits and molecular characterization of trait specific candidate genotypes using 26 (20 random and 6 genic) SSR markers. Trait characterization revealed significant variation for early maturity and related traits. The analysis of genotypic data of 26 markers led to the detection of 166 alleles ranging from 2 to 8 alleles with an average of 3.8 alleles per locus. Separate analysis of genotypic data of 20 random and 06 trait specefic markers led to the identification of 118 and 51 alleles, respectively. Sub-population-wise allelic diversity in early and late maturing populations could detect a total of 167 and 144 alleles, respectively. Higher gene diversity was detected in early maturing sub-population (0.135) when compared to late maturing sub-population (0.071). Single marker analysis (SMA) revealed significant association of 05 random and 02 trait specific markers already reported for early maturity. Therefore, two trait specific markers (Xwmc1 and Xgwm271) have been validated during the present study and contributed 21.36% and 10.94% phenotypic variation for early maturity, respectively. In order to breed for early maturity for Western-Himalayas, F2 segregating populations were also developed by making crosses among spring × spring and spring × winter wheat genotypes and several important recombinants/ segregants for early maturity and related traits were identified. Overall, the findings of the present study will prove useful in future wheat improvement programs leading to development of early maturing wheat varieties.

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Characterization of Genetic Diversity of Stone Fruit Rootstocks Used in Chile by Means of Microsatellite Markers

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.137.5.302 ◽

2012 ◽

Vol 137 (5) ◽

pp. 302-310 ◽

Cited By ~ 3

Author(s):

María José Arismendi ◽

Patricio Hinrichsen ◽

Ruben Almada ◽

Paula Pimentel ◽

Manuel Pinto ◽

...

Keyword(s):

Genetic Diversity ◽

Microsatellite Markers ◽

Ssr Markers ◽

Stone Fruit ◽

Identification System ◽

Expected Heterozygosity ◽

Commercially Important ◽

Taxonomic Groups ◽

Simple Sequence

Stone fruit (Prunus L.) production in Chile covers ≈43,000 ha and includes a wide variety of soils and climates requiring a large diversity of rootstocks. The most commercially important rootstock cultivars are 26 genotypes from three different taxonomic groups belonging to the subgenera Amygdalus (L.) Benth. Hook. (peach group), Prunus Focke [= Prunophora (Neck.)] Focke (plum group), and Cerasus (Adans.) Focke (cherry group) with eight, seven, and 10 individuals, respectively. To determine their genetic diversity, characterization by microsatellite markers [simple sequence repeat (SSR)] was conducted. Of a total of 20 SSR markers evaluated, 12 generated amplified products that were consistent in the three taxonomic groups. The number of alleles per marker ranged from 18 for PSM-3 to four in CPPCT-002. Clustering analysis, by both traditional hierarchical and model-based approaches, indicate that all genotypes are clustered in their respective taxonomic groups, including the interspecific hybrids. Genetic diversity, measured as the average distances (expected heterozygosity) between individuals in the same cluster, was higher in Cerasus (0.78) followed by Prunus (0.72) and Amygdalus (0.64). Total number of alleles observed was 133, of which 14, 33, and 35 from six, 10, and 10 loci were unique for the peach, plum, and cherry rootstock groups, respectively. Alleles shared among peach/plum, plum/cherry, and peach/cherry rootstock genotypes were 13, 14, and 18 from nine, seven, and seven loci, respectively. Only six alleles from five loci were common to the three taxonomic groups. In addition, to develop a rootstock identification system based on SSR markers, a minimum set of three markers (PMS-3, BPPCT-037, and BPPCT-036) able to differentiate the 26 genotypes was identified. This study is the first step toward establishing a stone fruit rootstock breeding program in Chile.

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Development of genomic simple sequence repeat markers for Glycyrrhiza lepidota and cross-amplification of other Glycyrrhiza species

PeerJ ◽

10.7717/peerj.7479 ◽

2019 ◽

Vol 7 ◽

pp. e7479

Author(s):

Jun Hyoung Bang ◽

Chi Eun Hong ◽

Sebastin Raveendar ◽

Kyong Hwan Bang ◽

Kyung Ho Ma ◽

...

Keyword(s):

Genetic Diversity ◽

Ssr Markers ◽

Simple Sequence Repeat ◽

Sequence Information ◽

Sequence Repeat ◽

Biotic Stresses ◽

Molecular Studies ◽

Cultivated Species ◽

Simple Sequence ◽

Genomic Simple Sequence Repeat

Background Licorice (Glycyrrhiza spp. L.) is used as a natural sweetener and medicinal herb in European and Asian countries. Molecular studies have been conducted to find differences between wild and cultivated species because most wild species are highly resistant to abiotic and biotic stresses compared with their cultivated species. However, few molecular markers have been developed for studying the genetic diversity and population structure of licorice species and to identify differences between cultivars. Thus, the present study aimed to develop a set of genomic simple sequence repeat (SSR) markers for molecular studies of these species. Methods In the present study, we developed polymorphic SSR markers based on whole-genomesequence data of Glycyrrhiza lepidota. Then, based on the sequence information, the polymorphic SSR markers were developed. The SSR markers were applied to 23 Glycyrrhiza individual plants. We also evaluated the phylogenetic relationships and interspecies transferability among samples. Results The genetic diversity analysis using these markers identified 2–23 alleles, and the major allele frequency, observed heterozygosity, genetic diversity, and polymorphism information content were 0.11–0.91, 0–0.90, 0.17–0.94, and 0.15–0.93, respectively. Interspecies transferability values were 93.5%, 91.6%, and 91.1% for G. echinata, G. glabra, and G. uralensis, respectively. Phylogenetic analysis clustered cultivated (group 1) and wild (group 2) species into three and two subgroups, respectively. The reported markers represent a valuable resource for the genetic characteri z ation of Glycyrrhiza spp. for theanalysis of its genetic variability, and as a tool for licorice transferability. This is the first intraspecific study in a collection of Glycyrrhiza spp. germplasm using SSR markers.

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Molecular characterization using SSR markers in 50 shrub pea genotypes (Pisum sativum L.) from the GRICAND Collection, Colombia

Revista Colombiana de Ciencias Hortícolas ◽

10.17584/rcch.2019v13i2.10177 ◽

2019 ◽

Vol 13 (2) ◽

pp. 208-218

Author(s):

Juan Diego Duque-Zapata ◽

Jaime Eduardo Muñoz ◽

Oscar Checa-Coral

Keyword(s):

Pisum Sativum ◽

Ssr Markers ◽

Polymorphic Information Content ◽

Genetic Relationships ◽

Similarity Index ◽

Morphological Characteristics ◽

High Similarity ◽

Expected Heterozygosity ◽

Pisum Sativum L ◽

Simple Sequence

The pea (Pisum sativum L.) is one of the more important legume crops produced globally. We studied the structure and genetic diversity in a collection of 50 pea accessions with 16 simple sequence repeat (SSR) markers, whose average polymorphic information content (PIC) was 0.62. The SSR markers amplified a total of 28 alleles with an average of 4 alleles per locus, with locus AB71 and D21 amplifying the largest number of alleles (6). The observed heterozygosity (Ho) was 0.09±0.08 and the expected heterozygosity (He) was 0.42, indicating an elevated level of inbreeding (Fis = 0.60). The genetic relationships were inferred with a similarity index (DICE) and a bayesian analysis (STRUCTURE), detecting 2 clusters for the genotypes, with a high similarity of the morphological characteristics of each genotype. The results of this study will be useful for the creation of future breeding programs.The pea (Pisum sativum L.) is one of the more important legume crops produced globally. We studied the structure and genetic diversity in a collection of 50 pea accessions with 16 simple sequence repeat (SSR) markers, whose average polymorphic information content (PIC) was 0.62. The SSR markers amplified a total of 28 alleles with an average of 4 alleles per locus, with locus AB71 and D21 amplifying the largest number of alleles (6). The observed heterozygosity (Ho) was 0.09±0.08 and the expected heterozygosity (He) was 0.42, indicating an elevated level of inbreeding (Fis = 0.60). The genetic relationships were inferred with a similarity index (DICE) and a bayesian analysis (STRUCTURE), detecting 2 clusters for the genotypes, with a high similarity of the morphological characteristics of each genotype. The results of this study will be useful for the creation of future breeding programs.

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Development of SSR Markers and Genetic Diversity Evaluation of Mycocentrospora Acerina Causing Round Spot of Panax Notoginseng in Yunan Province, China

10.21203/rs.3.rs-1204134/v1 ◽

2022 ◽

Author(s):

Huiling Wang ◽

Kuan Yang ◽

Liwei Guo ◽

Lifen Luo ◽

Chi He ◽

...

Keyword(s):

Genetic Diversity ◽

Ssr Markers ◽

Yunnan Province ◽

Polymorphic Information Content ◽

Polyacrylamide Gel Electrophoresis ◽

Panax Notoginseng ◽

Expected Heterozygosity ◽

Ssr Primers ◽

Polymorphic Microsatellite ◽

Simple Sequence

Abstract Sanqi round spot, which is caused by Mycocentrospora acerina, is a destructive disease limits the production of Panax notoginseng in Yunnan province of China. However, the disease has not been studied comprehensively. In the current study, we identify M. acerina polymorphic microsatellite markers using CERVUS 3.0 and compare the genetic diversity of its isolates from P. notoginseng round spot using Simple Sequence Repeat (SSR) markers and polyacrylamide gel electrophoresis. Thirty-two SSR markers with good polymorphism were developed using MISA and CERVUS 3.0. The genetic diversity of 187 M. acerina isolates were evaluated using 14 representative SSR primers, and the polymorphic information content values of 14 sites ranged from 0.813 to 0.946, with a total of 264 alleles detected at 14 microsatellite loci. The average expected heterozygosity was 0.8967. The genetic diversity of M. acerina in Yunnan province does not reflect geographic specificity.

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Simple sequence repeats for germplasm analysis and mapping in maize

Genome ◽

10.1139/g96-038 ◽

1996 ◽

Vol 39 (2) ◽

pp. 277-287 ◽

Cited By ~ 108

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.

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