A comparative assessment of genetic diversity in cultivated barley collected in different decades of the last century in Austria, Albania and India by using genomic and genic simple sequence repeat (SSR) markers

2006 ◽  
Vol 4 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Elena K. Khlestkina ◽  
Rajeev K. Varshney ◽  
Marion S. Röder ◽  
Andreas Graner ◽  
Andreas Börner

Molecular investigations of qualitative and quantitative changes in the genetic diversity of cultivated crops are useful for plant breeding and the management of crop genetic resources. A genotyping study, based on 28 genomic (g-SSR) and 13 expressed sequence tag-derived (e-SSR) microsatellite markers uniformly distributed across the barley genome, was conducted on samples of cultivated barley (Hordeum vulgare L.) collected at intervals of 40–50 years in three comparable geographical regions in Austria, Albania and India. The analysis indicated an absence of any significant differences either in the total number of alleles per locus or in g-SSR and e-SSR polymorphic information content (PIC) values from the Indian and Austrian materials. However, a slight reduction in genetic diversity was noted among the materials collected in Albania. The trend in numbers of collection mission-specific SSR alleles suggests significant allele flow over the time interval sampled. The g-SSRs yielded a higher mean number of alleles per locus and a superior PIC than the e-SSR markers. We conclude that a qualitative, rather than a quantitative shift in diversity has taken place over time, and that g-SSR markers detect more diversity than do e-SSR markers.

Crustaceana ◽  
2019 ◽  
Vol 92 (7) ◽  
pp. 841-851
Author(s):  
Xuekai Han ◽  
Ruyi Xu ◽  
Yuyu Zheng ◽  
Meirong Gao ◽  
Liying Sui

Abstract Artemia is one of the most important live food items used in larviculture. In order to study the genetic diversity of Artemia in China, 170 novel simple sequence repeats (SSR) markers were identified from expressed sequence tags (ESTs) of the transcriptome library of Artemia parthenogenetica. Of these, 8 microsatellite loci were developed to characterize three geographical populations of Artemia. The results showed the expected and observed heterozygosity varied from 0.43 to 0.50 and from 0.59 to 0.64, respectively. The PIC (polymorphic information content) ranged from 0.37 to 0.45. These observations indicated that the Yuncheng population has the highest genetic diversity, whereas the Shuanghu population has the lowest. The Fst value (genetic differentiation coefficient) indicated that the three populations are highly differentiated. Genetic identity analyses revealed that the Yuncheng and Shuanghu populations have the closest relationship. The SSR markers described here will serve as a valuable tool for further studies in population and conservation genetics on Artemia.


2021 ◽  
Vol 12 ◽  
Author(s):  
Haftom Brhane ◽  
Teklehaimanot Haileselassie ◽  
Kassahun Tesfaye ◽  
Cecilia Hammenhag ◽  
Rodomiro Ortiz ◽  
...  

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.


2016 ◽  
Vol 154 (7) ◽  
pp. 1254-1269 ◽  
Author(s):  
A. SINGH ◽  
H. K. DIKSHIT ◽  
D. SINGH ◽  
N. JAIN ◽  
M. ASKI ◽  
...  

SUMMARYExpressed sequence tag-simple sequence repeat (EST-SSR) markers were used to analyse genetic diversity among three Lens species. The SSR loci amplified successfully in wild species, with 94·82% transferability in Lens culinaris subsp. orientalis, 95·4% in Lens nigricans, 98·81% in L. culinaris subsp. odemensis, 94·82% in L. culinaris subsp. tomentosus and 96·55% in Lens ervoides. Ninety-nine alleles (average 3·41 alleles/locus) were detected by 29 SSR markers. Based on the unweighted pair group method with arithmetic mean cluster analysis, all the genotypes were grouped into three clusters at a similarity level of 0·30. The diversity analysis indicated no species-specific clustering of the wild and cultivated species. Wild species L. nigricans and L. culinaris subsp. odemensis, L. culinaris subsp. orientalis and L. ervoides were grouped in Cluster I, whereas the Mediterranean land races of L. culinaris subsp. culinaris and L. culinaris subsp. tomentosus formed a separate group in Cluster II A. Cluster II B comprised L. ervoides, L. culinaris subsp. orientalis and L. culinaris subsp. culinaris. Clusters II C, II D and II F included cultivated Indian lentil genotypes. Cluster II E comprised Indian and Mediterranean germplasm lines. Cluster II F included three early maturing germplasm lines, whereas Cluster III included only two germplasm lines. The functional annotation of SSR-containing unigenes revealed that a majority of genes were involved in an important transport-related function or were a component of metabolic pathways. A high level of polymorphism of EST-SSRs and their transferability to related wild species indicated that these markers could be used for molecular screening, map construction, comparative genomic studies and marker-assisted selection.


Genome ◽  
2005 ◽  
Vol 48 (4) ◽  
pp. 731-737 ◽  
Author(s):  
N A Barkley ◽  
M L Newman ◽  
M L Wang ◽  
M W Hotchkiss ◽  
G A Pederson

Polymorphic expressed sequence tag - simple sequence repeat (EST-SSR) markers derived from major cereal crops were used to assess the genetic diversity of the USDA temperate bamboo collection consisting of 92 accessions classified in 11 separate genera and 44 species. A total of 211 bands were detected with a mean number of alleles per locus of 8.440. Phylogenetic relationships were determined by calculating genetic distances between all pairwise combinations and assessing differences in character data. The resulting dendrograms (unweighted pair group method with arithmetic means (UPGMA) and parsimony) clustered the accessions into 2 main clades, which corresponded to accessions characterized morphologically as either clumping (sympodial) or running (monopodial) bamboos. The majority of the accessions clustered according to their current taxonomic classification. These markers were also beneficial in identifying contaminated and (or) misidentified plots. Overall, these transferred markers were informative in differentiating the various bamboo accessions and determining the level of genetic variation within and among species and genera.Key words: bamboo germplasm, genetic diversity, phylogeny.


Genome ◽  
2006 ◽  
Vol 49 (6) ◽  
pp. 707-715 ◽  
Author(s):  
M L Wang ◽  
J A Mosjidis ◽  
J B Morris ◽  
R E Dean ◽  
T M Jenkins ◽  
...  

The genetic diversity of the genus Crotalaria is unknown even though many species in this genus are economically valuable. We report the first study in which polymorphic expressed sequence tag-simple sequence repeat (EST-SSR) markers derived from Medicago and soybean were used to assess the genetic diversity of the Crotalaria germplasm collection. This collection consisted of 26 accessions representing 4 morphologically characterized species. Phylogenetic analysis partitioned accessions into 4 main groups generally along species lines and revealed that 2 accessions were incorrectly identified as Crotalaria juncea and Crotalaria spectabilis instead of Crotalaria retusa. Morphological re-examination confirmed that these 2 accessions were misclassified during curation or conservation and were indeed C. retusa. Some amplicons from Crotalaria were sequenced and their sequences showed a high similarity (89% sequence identity) to Medicago truncatula from which the EST-SSR primers were designed; however, the SSRs were completely deleted in Crotalaria. Highly distinguishing markers or more sequences are required to further classify accessions within C. juncea.Key words: Crotalaria germplasm, EST-SSR, genetic diversity, phylogeny.


2009 ◽  
Vol 7 (02) ◽  
pp. 169-176 ◽  
Author(s):  
M. A. Ould Med Mahmoud ◽  
S. Hamza

To assess the genetic diversity among Tunisian local barley, a set of 120 barley accessions representing five distinct geographical regions (North-West, Littoral, South, Jerba and Kerkennah Islands) was characterized with 20 simple sequence repeats (SSR) and 8 expressed sequence tag (EST)-SSR markers. The 28 loci revealed a total of 98 alleles, with an average of 3.76 alleles per locus (range 2–10). Gene diversity averaged 0.50 (range 0.09–0.84). Partitioning analysis of genetic diversity showed that about 95% of the total variation was within regions and no geographical differentiation could be found except for the North-West population. Similarly, neighbour joining clustering of the genotypes did not indicate any clear pattern of division among the barley accessions based on geographical origin. These results may reflect the impact of seed exchange between farmers which is likely to limit highlighting favourable alleles due to local adaptation.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xingwen Zheng ◽  
Teng Cheng ◽  
Liangbo Yang ◽  
Jinxing Xu ◽  
Jiping Tang ◽  
...  

Abstract Twenty-two sacred lotus (Nelumbo nucifera), 46 taros (Colocasia esculenta) and 10 arrowheads (Sagittaria trifolia) were used as materials and combined with EST-SSR (expressed sequence tag-simple sequence repeats) primers developed by our laboratory. Core primers were screened from a large number of primers that were able to distinguish all materials with a high frequency of polymorphisms. Six pairs, twenty pairs and three pairs of core primers were screened from sacred lotus, taro, and arrowhead, respectively. The SSR fingerprints of these three important aquatic vegetables, producing 17-, 87- and 14-bit binary molecular identity cards, respectively, were separately determined by using the core primers. Since there were few core primers of sacred lotus and arrowhead, 3 and 9 primer pairs with higher polymorphic information content (PIC), respectively, were selected as candidate primers. These core and candidate primers were used to identify the purities of No.36 space lotus, Shandong 8502 taro and Wuhan arrowhead, which were 93.3% (84/90), 98.9% (89/90) and 100.0% (90/90), respectively. The fingerprints, displayed as binary molecular identification cards of three important aquatic vegetables, were obtained, and their purity was successfully determined with EST-SSR labeling technology. Phylogenetic trees were also constructed to analyze the genetic diversity of 22 sacred lotus, 46 taros and 10 arrowheads. This study classifies and identifies germplasm resources and is an important reference to test the authenticity and variety purity of other aquatic vegetables in the future.


2017 ◽  
Vol 17 (1) ◽  
pp. 17 ◽  
Author(s):  
Nur Kholilatul Izzah ◽  
Reflinur Reflinur ◽  
Tae-Jin Yang

<p>Development of Expressed Sequence Tag-Simple Sequence Repeat (EST-SSR) markers derived from public database is known to be more efficient, faster and low cost. The objective of this study was to generate a new set of EST-SSR markers for broccoli and its related species and their usefulness for assessing their genetic diversity. A total of 202 Brassica oleracea ESTs were retrieved from NCBI and then assembled into 172 unigenes by means of CAP3 program. Identification of SSRs was carried out using web-based tool, RepeatMasker software. Afterwards, EST-SSR markers were developed using Primer3 program. Among the identified SSRs, trinucleotide repeats were the most common repeat types, which accounted for about 50%. A total of eight primer pairs were successfully designed and yielded amplification products. Among them, five markers were polymorphic and displayed a total of 30 alleles with an average number of six alleles per locus. The polymorphic markers were subsequently used for analyzing genetic diversity of 36 B. oleracea cultivars including 22 broccoli, five cauliflower and nine kohlrabi cultivars based on genetic similarity matrix as implemented in NTSYS program. At similarity coefficient of 61%, a UPGMA clustering dendrogram effectively separated 36 genotypes into three main groups, where 30 out of 36 genotypes were clearly discriminated. The result obtained in the present study would help breeders in selecting parental lines for crossing. Moreover, the novel EST-SSR markers developed in the study could be a valuable tool for differentiating cultivars of broccoli and related species.</p>


2009 ◽  
Vol 134 (3) ◽  
pp. 337-347 ◽  
Author(s):  
David Jesús Gil-Ariza ◽  
Iraida Amaya ◽  
José Manuel López-Aranda ◽  
José Federico Sánchez-Sevilla ◽  
Miguel Ángel Botella ◽  
...  

Unlike other important crops analyzed so far for genetic diversity and population structure, the brief history and particularities of the genetics of the cultivated strawberry (Fragaria ×ananassa Duchesne) have limited its genetic characterization. The genomic composition and the pattern of inheritance have not been fully elucidated, although a number of studies have suggested a highly diploidized genome. In this study, the similarity relationships and structure of 92 selected strawberry cultivars with widely diverse origins have been established using simple sequence repeat (SSR) markers derived from expressed sequence tags (EST-SSR markers). Genetic analysis performed by the unweighted pair group method with arithmetic mean clustering revealed a distribution according to both date of cultivar release and breeding for a specific climatic adaptation. Additionally, a model-based clustering approach identified three populations among the strawberry cultivars with an overall FST value of 0.15 to 0.16. Both analyses support a limited differentiation of modern cultivars, most probably as a consequence of the methodology of strawberry breeding. Interestingly, the collection of strawberry cultivars here analyzed showed comparable genetic differentiation to that observed in natural populations of Fragaria chiloensis (L.) Mill., one of its wild ancestors. Our results suggest that breeding has produced a small but significant reduction on the genetic diversity of F. ×ananassa. The panel of 10 EST-SSRs described in this work provided an extremely low probability of confusion (less than 10−11), offering an efficient and accurate method for cultivar identification.


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