Genetic diversity of Crotalaria germplasm assessed through phylogenetic analysis of EST-SSR markers

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.

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.


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.


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>


2018 ◽  
Vol 19 (9) ◽  
pp. 2492 ◽  
Author(s):  
Qi Guo ◽  
Xiuyu Li ◽  
Shuhong Yang ◽  
Zhiheng Yang ◽  
Yuhan Sun ◽  
...  

Understanding the genetic diversity and differentiation of the genetic resources of a species is important for the effective use and protection of forest tree resources. Ex situ development is a common method for the protection of genetic diversity and an essential resource for users who require ready access to a species’ germplasm. In this study, we collected seeds of black locust (Robinia pseudoacacia L.) from 19 provenances, covering most of its natural distribution; we randomly selected 367 tender leaves with well-grown and different maternal strains from this group for further analysis. Forty-eight simple sequence repeat (SSR) primers were successfully selected from 91 pairs of SSR primers using native-deformation polyacrylamide gel electrophoresis. In addition, we identified identical genotypes among all individuals and evaluated the quality of the markers. From this, 35 loci were confirmed for analyses of genetic diversity and differentiation of the black locust provenances, which contained 28 expressed sequence tag-derived simple sequence repeats (EST-SSRs) and 7 genomic DNA-derived simple sequence repeats (G-SSRs). We observed high genetic diversity among the native black locust provenances, from which Wright’s fixation index and molecular variance suggested that a majority of the genetic differentiation variation could be attributed to within-provenance differences. The genetic distance and identity results indicated that geographic distance was not a dominating factor influencing the distribution of black locust. This is the first study to evaluate provenance genetic variation in native black locust samples using two types of SSR markers, which provides a comprehensive theoretical basis for ex situ conservation and utilization of genetic resources, with an emphasis on breeding applications.


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.


2013 ◽  
Vol 2 (3) ◽  
pp. 137-146
Author(s):  
Liu Pei-Qing ◽  
Wu Min-Liang ◽  
Li Ben-Jin ◽  
Lan Cheng-Zhong ◽  
Weng Qi-Yong ◽  
...  

Phytophthora capsici is a highly dynamic and destructive pathogen of vegetable and great interests on the genetic structure of P. capsici have grown in the world. However, there is little genetic information about P. capsici based on the EST-SSR markers. In this study, 193 SSR markers were developed and 33 selected markers were successfully detected and they were polymorphic with the number of alleles per locus ranging from 2 to 7. 4 SSR markers were further selected for genetic diversity analysis and Nei’s genetic diversity values of 15 populations ranged from 0.38 to 0.66, with an average of 0.53. The higher polymorphism and greater transport ability of these markers among P. capsici species were proved by the expected heterozygosity (He =0.64) and Shannon’s index of diversity (I =1.14), indicating that they maintained a substantial level of genetic diversity. Additionally, the genetic differentiation among the 4 markers (Fst =0.15) was moderate and the gene flow among groups was consequent (Nm =1.69). Clustering analyses revealed that 15 populations are made of two differentiated genetic clusters and are similar regarding genetic diversity composition. Our results suggest that there are considerable evolutionary potential of P. capsici in China and useful management strategies should be adapt to it.


Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 471
Author(s):  
Jae-Ryoung Park ◽  
Won-Tae Yang ◽  
Yong-Sham Kwon ◽  
Hyeon-Nam Kim ◽  
Kyung-Min Kim ◽  
...  

The assessment of the genetic diversity within germplasm collections can be accomplished using simple sequence repeat (SSR) markers and association mapping techniques. The present study was conducted to evaluate the genetic diversity of a colored rice germplasm collection containing 376 black-purple rice samples and 172 red pericarp samples, conserved by Dong-A University. There were 600 pairs of SSR primers screened against 11 rice varieties. Sixteen informative primer pairs were selected, having high polymorphism information content (PIC) values, which were then used to assess the genetic diversity within the collection. A total of 409 polymorphic amplified fragments were obtained using the 16 SSR markers. The number of alleles per locus ranged from 11 to 47, with an average of 25.6. The average PIC value was 0.913, ranging from 0.855 to 0.964. Four hundred and nine SSR loci were used to calculate Jaccard’s distance coefficients, using the unweighted pair-group method with arithmetic mean cluster analysis. These accessions were separated into several distinctive groups corresponding to their morphology. The results provided valuable information for the colored rice breeding program and showed the importance of protecting germplasm resources and the molecular markers that can be derived from them.


2013 ◽  
Vol 138 (4) ◽  
pp. 290-296 ◽  
Author(s):  
Raúl De la Rosa ◽  
Angjelina Belaj ◽  
Antonio Muñoz-Mérida ◽  
Oswaldo Trelles ◽  
Inmaculada Ortíz-Martín ◽  
...  

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.


HortScience ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 283-287
Author(s):  
Xiu Cai Fan ◽  
Hai Sheng Sun ◽  
Ying Zhang ◽  
Jian Fu Jiang ◽  
Min Li ◽  
...  

In this study, simple sequence repeat (SSR) and sequence-related amplified polymorphism (SRAP) markers were used to analyze the genetic diversity of 48 wild Vitis davidii accessions. A total of 78 distinct alleles were amplified by 11 SSR primers, and the average allele number was 8.8. The average observed heterozygosity (Ho) and expected heterozygosity (He) values were 0.785 and 0.814, respectively. The effective allele numbers ranged from 3.92 to 9.61. The average polymorphism information content (PIC) was 0.798. Twelve of 169 SRAP primer combinations were selected for SRAP analysis. A total of 188 bands were produced, and the average was 15.7 bands per primer combination; the average percentage of polymorphic bands was 84.0%. The average PIC was 0.76. The results of the clustering analysis based on SSR markers showed that the 48 wild V. davidii accessions could be classified into five main clusters and had a genetic similarity coefficient level of 0.68. The dendrogram obtained from the SRAP data showed that 48 wild V. davidii accessions could be classified into five main clusters and had a genetic similarity coefficient of 0.72. SSR and SRAP markers differentiated all accessions studied including those with a similar pedigree. We speculated on the origin of Ciputao 0941♀, Ciputao 0940♂, and Fu’an-ci-01 using SSR markers and used both SSR and SRAP markers to resolve homonymy. The result will be valuable for further management and protection of V. davidii germplasm resources.


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