scholarly journals Development and Characterization of High-Throughput EST-Based SSR Markers for Pogostemon cablin Using Transcriptome Sequencing

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 2014 ◽  
Author(s):  
Puyue Ouyang ◽  
Dali Kang ◽  
Xiaolu Mo ◽  
Enwei Tian ◽  
Yanyu Hu ◽  
...  

Simple sequence repeats (SSRs) or microsatellite markers derived from expressed sequence tags (ESTs) are routinely used for molecular assisted-selection breeding, comparative genomic analysis, and genetic diversity studies. In this study, we investigated 54,546 ESTs for the identification and development of SSR markers in Pogostemon cablin (Patchouli). In total, 1219 SSRs were identified from 1144 SSR-containing ESTs. Trinucleotides (80.8%) were the most abundant SSRs, followed by di- (10.8%), mono- (7.1%), and hexa-nucleotides (1.3%). The top six motifs were CCG/CGG (15.3%), AAG/CTT (15.0%), ACC/GGT (13.5%), AGG/CCT (12.4%), ATC/ATG (9.9%), and AG/CT (9.8%). On the basis of these SSR-containing ESTs, a total of 192 primer pairs were randomly designed and used for polymorphism analysis in 38 accessions collected from different geographical regions of Guangdong, China. Of the SSR markers, 45 were polymorphic and had allele variations from two to four. Furthermore, a transferability analysis of these primer pairs revealed a 10–40% cross-species transferability in 10 related species. This report is the first comprehensive study on the development and analysis of a large set of SSR markers in P. cablin. These markers have the potential to be used in quantitative trait loci mapping, genetic diversity studies, and the fingerprinting of cultivars of P. cablin.

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 82 ◽  
Author(s):  
Suliya Ma ◽  
Wenxuan Dong ◽  
Tong Lyu ◽  
Yingmin Lyu

Chinese hawthorn (Crataegus pinnatifida) is an important ornamental and economic horticultural plant. However, the lack of molecular markers has limited the development and utilization of hawthorn germplasm resources. Simple sequence repeats (SSRs) derived from expressed sequence tags (ESTs) allow precise and effective cultivar characterization and are routinely used for genetic diversity analysis. Thus, we first reported the development of polymorphic EST-SSR markers in C. pinnatifida with perfect repeats using Illumina RNA-Seq technique. In total, we investigated 14,364 unigenes, from which 5091 EST-SSR loci were mined. Di-nucleotides (2012, 39.52%) were the most abundant SSRs, followed by mono- (1989, 39.07%), and tri-nucleotides (1024, 20.11%). On the basis of these EST-SSRs, a total of 300 primer pairs were designed and used for polymorphism analysis in 70 accessions collected from different geographical regions of China. Of 239 (79.67%) pairs of primer-generated amplification products, 163 (54.33%) pairs of primers showed polymorphism. Finally, 33 primers with high polymorphism were selected for genetic diversity analysis and tested on 70 individuals with low-cost fluorescence-labeled M13 primers using capillary electrophoresis genotyping platform. A total of 108 alleles were amplified by 33 SSR markers, with the number of alleles (Na) ranging from 2 to 14 per locus (mean: 4.939), and the effective number of alleles (Ne) ranging from 1.258 to 3.214 (mean: 2.221). The mean values of gene diversity (He), observed heterozygosity (Ho), and polymorphism information content (PIC) were 0.524 (range 0.205–0.689), 0.709 (range 0.132–1.000), and 0.450 (range 0.184–0.642), respectively. Furthermore, the dendrogram constructed based on the EST-SSR separated the cultivars into two main clusters. In sum, our study was the first comprehensive study on the development and analysis of a large set of SSR markers in hawthorn. The results suggested that the use of NGS techniques for SSR development represented a powerful tool for genetic studies. Additionally, fluorescence-labeled M13 markers proved to be a valuable method for genotyping. All of these EST-SSR markers have agronomic potential and constitute a scientific basis for future studies on the identification, classification, and innovation of hawthorn germplasms.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yuanyuan Xu ◽  
Miaomiao Xing ◽  
Lixiao Song ◽  
Jiyong Yan ◽  
Wenjiang Lu ◽  
...  

Cabbage (Brassica oleracea L. var. capitata) accounts for a critical vegetable crop belonging to Brassicaceae family, and it has been extensively planted worldwide. Simple sequence repeats (SSRs), the markers with high polymorphism and co-dominance degrees, offer a crucial genetic research resource. The current work identified totally 64,546 perfect and 93,724 imperfect SSR motifs in the genome of the cabbage ‘TO1000.’ Then, we divided SSRs based on the respective overall length and repeat number into different linkage groups. Later, we characterized cabbage genomes from the perspectives of motif length, motif-type classified and SSR level, and compared them across cruciferous genomes. Furthermore, a large set of 64,546 primer pairs were successfully identified, which generated altogether 1,113 SSR primers, including 916 (82.3%) exhibiting repeated and stable amplification. In addition, there were 32 informative SSR markers screened, which might decide 32 cabbage genotypes for their genetic diversity, with level of polymorphism information of 0.14–0.88. Cultivars were efficiently identified by the new strategy designating manual diagram for identifying cultivars. Lastly, 32 cabbage accessions were clearly separately by five Bol-SSR markers. Besides, we verified whether such SSRs were available and transferable in 10 Brassicaceae relatives. Based on the above findings, those genomic SSR markers identified in the present work may facilitate cabbage research, which lay a certain foundation for further gene tagging and genetic linkage analyses, like marker-assisted selection, genetic mapping, as well as comparative genomic analysis.


2005 ◽  
Vol 3 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Sally L. Dillon ◽  
Peter K. Lawrence ◽  
Robert J. Henry

The Sorghum genus is extremely diverse both morphologically and geographically, however, relatively few of the 25 recognized species have been evaluated genetically. The apparent lack of basic knowledge pertaining to the levels of genetic diversity both within and between the 17 Australian wild species is a major obstacle to both their effective conservation and potential use in breeding programmes. Twelve Sorghum bicolor-derived simple sequence repeat (SSR) markers were evaluated for cross-species amplification in all 25 Sorghum species. The SSR markers were highly polymorphic, with diversity indices ranging from 0.59 to 0.99 with mean of 0.91. Five markers combined were able to differentiate 24 of the 25 Sorghum species, with intra-species polymorphism apparent. Sorghum bicolor-derived SSRs have proven to be an efficient source of markers for genetic diversity studies of the relatively poorly characterized Australian indigenous Sorghum species.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8038
Author(s):  
Yanli Xiong ◽  
Wenhui Liu ◽  
Yi Xiong ◽  
Qingqing Yu ◽  
Xiao Ma ◽  
...  

Hosting unique and important plant germplasms, the Qinghai-Tibet Plateau (QTP), as the third pole of the world, and Xinjiang, located in the centre of the Eurasian continent, are major distribution areas of perennial Triticeae grasses, especially the widespread Elymus species. Elymus excelsus Turcz. ex Griseb, a perennial forage grass with strong tolerance to environmental stresses, such as drought, cold and soil impoverishment, can be appropriately used for grassland establishment due to its high seed production. To provide basic information for collection, breeding strategies and utilization of E. excelsus germplasm, microsatellite markers (SSR) were employed in the present study to determine the genetic variation and population structure of 25 wild accessions of E. excelsus from Xinjiang (XJC) and the QTP, including Sichuan (SCC) and Gansu (GSC) of western China. Based on the 159 polymorphic bands amplified by 35 primer pairs developed from three related species, the average values of the polymorphic information content (PIC), marker index (MI), resolving power (Rp), Nei’s genetic diversity (H) and Shannon’s diversity index (I) of each pair of primers were 0.289, 1.348, 1.897, 0.301 and 0.459, respectively, validating that these SSR markers can also be used for the evaluation of genetic diversity of E. excelsus germplasms, and demonstrating the superior versatility of EST-SSR vs. G-SSR. We found a relatively moderate differentiation (Fst = 0.151) among the XJC, SCC and GSC geo-groups, and it is worth noting that, the intra-group genetic diversity of the SCC group (He = 0.197) was greater than that of the GSC (He = 0.176) and XJC (He = 0.148) groups. Both the Unweighted Pair Group Method with Arithmetic (UPGMA) clustering and principal coordinates analysis (PCoA) divided the 25 accessions into three groups, whereas the Bayesian STRUCTURE analysis suggested that E. excelsus accessions fell into four main clusters. Besides, this study suggested that geographical distance and environmental variables (annual mean precipitation and average precipitation in growing seasons), especially for QTP accessions, should be combined to explain the population genetic differentiation among the divergent geographical regions. These data provided comprehensive information about these valuable E. excelsus germplasm resources for the protection and collection of germplasms and for breeding strategies in areas of Xinjiang and QTP in western China.


mSystems ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Zhiqiu Yin ◽  
Si Zhang ◽  
Yi Wei ◽  
Meng Wang ◽  
Shuangshuang Ma ◽  
...  

The taxonomic position of P. shigelloides has been the subject of debate for a long time, and until now, the evolutionary dynamics and pathogenesis of P. shigelloides were unclear. In this study, pan-genome analysis indicated extensive genetic diversity and the presence of large and variable gene repertoires. Our results revealed that horizontal gene transfer was the focal driving force for the genetic diversity of the P. shigelloides pan-genome and might have contributed to the emergence of novel properties. Vibrionaceae and Aeromonadaceae were found to be the predominant donor taxa for horizontal genes, which might have caused the taxonomic confusion historically. Comparative genomic analysis revealed the potential of P. shigelloides to cause intestinal and invasive diseases. Our results could advance the understanding of the evolution and pathogenesis of P. shigelloides, particularly in elucidating the role of horizontal gene transfer and investigating virulence-related elements.


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.


2014 ◽  
Vol 12 (S1) ◽  
pp. S118-S120 ◽  
Author(s):  
Rajeev Varshney ◽  
Mahendar Thudi ◽  
Hari Upadhyaya ◽  
Sangam Dwivedi ◽  
Sripada Udupa ◽  
...  

A chickpea simple sequence repeat (SSR) marker reference kit has been developed based on the genotyping of the global chickpea composite collection (3,000 accessions) with 35 SSR markers. The kit consists of three pools of chickpea accessions along with supporting documentation on the SSR markers, polymerase chain reaction and detection conditions, and the expected allele sizes for each of the 35 SSR loci. These markers were selected based on quality criteria, genome coverage and locus-specific information content. Other important SSR selection criteria were quality of amplification products, locus complexity, polymorphism information content and well-dispersed location on a chickpea genetic map. The developed SSR kit has a wide range of applications, especially for genetic diversity studies in chickpea. Using the markers and reference accessions in the kit, scientists in other laboratories will be able to compare the genotypic data that they obtain for their germplasm with that obtained using the global composite collection.


Genome ◽  
2008 ◽  
Vol 51 (2) ◽  
pp. 91-103 ◽  
Author(s):  
R. K. Sharma ◽  
P. Gupta ◽  
V. Sharma ◽  
A. Sood ◽  
T. Mohapatra ◽  
...  

Simple sequence repeat (SSR) markers are valuable tools for many purposes such as phylogenetic, fingerprinting, and molecular breeding studies. However, only a few SSR markers are known and available in bamboo species of the tropics ( Bambusa spp.). Considering that grass genomes have co-evolved and share large-scale synteny, theoretically it should be possible to use the genome sequence based SSR markers of field crops such as rice ( Oryza sativa ) and sugarcane ( Saccharum spp.) for genome analysis in bamboo. To test this, 98 mapped SSR primers representing 12 linkage groups of rice and 20 EST-derived sugarcane SSR primers were evaluated for transferability to 23 bamboo species. Of the tested markers, 44 (44.9%) rice and 15 (75%) sugarcane SSR primers showed repeatable amplification in at least one species of bamboo and thus were successfully utilized for phylogenetic and genetic diversity analyses. Transferred SSR primers revealed complex amplification patterns in bamboo, with an average of 9.62 fragments per primer, indicating a high level of polyploidy and genetic variability in bamboo. Forty-two of these primers (34 rice and 8 sugarcane SSR primers) detected an average of 2.12 unique fragments per primer and thus could be exploited for species identification. Six bamboo SSR primers exhibited cross transferability, to varying degrees, to different bamboo species. The genetic similarity coefficient indicated a high level of divergence at the species level (73%). However, a relatively low level of diversity was observed within species (25% in 20 accessions of Dendrocalamus hamiltonii ). Further, cluster analysis revealed that the major grouping was in accordance with the taxonomical classification of bamboo. Thus, the rice and sugarcane SSRs can be utilized for phylogenetic and genetic diversity studies in bamboo.


mSystems ◽  
2021 ◽  
Author(s):  
Wangxiao Zhou ◽  
Ye Jin ◽  
Yanzi Zhou ◽  
Yuan Wang ◽  
Luying Xiong ◽  
...  

Understanding the evolution and dissemination of community-genotype ST72 Staphylococcus aureus isolates is important, as isolates of this lineage have rapidly spread into hospital settings and caused serious health issues. In this study, we first carried out genome-wide analysis of 107 global ST72 isolates to characterize the evolution and genetic diversity of the ST72 lineage.


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