scholarly journals Genotyping-By-Sequencing Reveals Population Structure and Genetic Diversity of a Buffelgrass (Cenchrus ciliaris L.) Collection

Diversity ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 88
Author(s):  
Alemayehu Teressa Negawo ◽  
Yilikal Assefa ◽  
Jean Hanson ◽  
Asebe Abdena ◽  
Meki S. Muktar ◽  
...  

Buffelgrass (Cenchrus ciliaris L.) is an important forage grass widely grown across the world with many good characteristics including high biomass yield, drought tolerance, and adaptability to a wide range of soil conditions and agro-ecologies. Two hundred and five buffelgrass accessions from diverse origins, conserved as part of the in-trust collection in the ILRI genebank, were analyzed by genotyping-by-sequencing using the DArTseq platform. The genotyping generated 234,581 single nucleotide polymorphism (SNP) markers, with polymorphic information content (PIC) values ranging from 0.005 to 0.5, and the short sequences of the markers were aligned with foxtail millet (Setaria italica) as a reference genome to generate genomic map positions of the markers. One thousand informative SNP markers, representing a broad coverage of the reference genome and with an average PIC value of 0.35, were selected for population structure and diversity analyses. The population structure analysis suggested two main groups, while the hierarchical clustering showed up to eight clusters in the collection. A representative core collection containing 20% of the accessions in the collection, with germplasm from 10 African countries and Oman, was developed. In general, the study revealed the presence of considerable genetic diversity and richness in the collection and a core collection that could be used for further analysis for specific traits of interest.

2021 ◽  
Author(s):  
Zhifei Zhao ◽  
Qinfei Song ◽  
Dingchen Bai ◽  
Suzhen Niu ◽  
Yingqin He ◽  
...  

Abstract Background Tea plants originated from the southwest of China. Guizhou is one of the origin center of tea plants, which is rich in tea plant germplasm resources. However, the distribution characteristics and transmission model of tea plant were still unclear. Results We collected 253 cultivated-type tea plant accessions from Guizhou plateau and analyzed the genetic diversity, PCA, phylogenetic, population structure, LD, and development of core collection using the genotyping-by-sequencing (GBS) approach. A total of 112,072 high-quality SNPs were identified, which was further used to analyze the genetic diversity and population structure. In this study, we found that the genetic diversity in cultivated-type tea accessions of PR Basin were significantly higher than that in cultivated-type tea accessions of YR Basin. Moreover, four groups, including three pure groups (CG-1, CG-2 and CG-3) and one admixture group (CG-4), were identified based on population structure analysis, which was verified by PAC and phylogenetic analysis. Our results showed that the highest GD and Fst values were found in CG-2 vs CG-3, followed by CG-1 vs CG-2 and CG-1 vs CG-3. The lowest GD and Fst values were detected in CG-4 vs CG-1, CG-4 vs CG-2, and CG-4 vs CG-3. Conclusions This study provided the evidence to confirm the contribution of PR and YR Basins and ancient hub road section to the transmission of cultivated-type tea accessions in Guizhou plateau. The genetic diversity, population structure and core collection revealed by our study will benefit further genetic studies, germplasm protection, and breeding.


2021 ◽  
Vol 12 ◽  
Author(s):  
Debjani Roy Choudhury ◽  
Ramesh Kumar ◽  
Vimala Devi S ◽  
Kuldeep Singh ◽  
N. K. Singh ◽  
...  

In India, rice (Oryza sativa L.) is cultivated under a variety of climatic conditions. Due to the fragility of the coastal ecosystem, rice farming in these areas has lagged behind. Salinity coupled with floods has added to this trend. Hence, to prevent genetic erosion, conserving and characterizing the coastal rice, is the need of the hour. This work accessed the genetic variation and population structure among 2,242 rice accessions originating from India’s east coast comprising Andhra Pradesh, Orissa, and Tamil Nadu, using 36 SNP markers, and have generated a core set (247 accessions) as well as a mini-core set (30 accessions) of rice germplasm. All the 36 SNP loci were biallelic and 72 alleles found with average two alleles per locus. The genetic relatedness of the total collection was inferred using the un-rooted neighbor-joining tree, which grouped all the genotypes (2,242) into three major clusters. Two groups were obtained with a core set and three groups obtained with a mini core set. The mean PIC value of total collection was 0.24, and those of the core collection and mini core collection were 0.27 and 0.32, respectively. The mean heterozygosity and gene diversity of the overall collection were 0.07 and 0.29, respectively, and the core set and mini core set revealed 0.12 and 0.34, 0.20 and 0.40 values, respectively, representing 99% of distinctiveness in the core and mini core sets. Population structure analysis showed maximum population at K = 4 for total collection and core collection. Accessions were distributed according to their population structure confirmed by PCoA and AMOVA analysis. The identified small and diverse core set panel will be useful in allele mining for biotic and abiotic traits and managing the genetic diversity of the coastal rice collection. Validation of the 36-plex SNP assay was done by comparing the genetic diversity parameters across two different rice core collections, i.e., east coast and northeast rice collection. The same set of SNP markers was found very effective in deciphering diversity at different genetic parameters in both the collections; hence, these marker sets can be utilized for core development and diversity analysis studies.


Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1190 ◽  
Author(s):  
Eunju Seo ◽  
Kipoong Kim ◽  
Tae-Hwan Jun ◽  
Jinsil Choi ◽  
Seong-Hoon Kim ◽  
...  

Cowpea is one of the most essential legume crops providing inexpensive dietary protein and nutrients. The aim of this study was to understand the genetic diversity and population structure of global and Korean cowpea germplasms. A total of 384 cowpea accessions from 21 countries were genotyped with the Cowpea iSelect Consortium Array containing 51,128 single-nucleotide polymorphisms (SNPs). After SNP filtering, a genetic diversity study was carried out using 35,116 SNPs within 376 cowpea accessions, including 229 Korean accessions. Based on structure and principal component analysis, a total of 376 global accessions were divided into four major populations. Accessions in group 1 were from Asia and Europe, those in groups 2 and 4 were from Korea, and those in group 3 were from West Africa. In addition, 229 Korean accessions were divided into three major populations (Q1, Jeonra province; Q2, Gangwon province; Q3, a mixture of provinces). Additionally, the neighbor-joining tree indicated similar results. Further genetic diversity analysis within the global and Korean population groups indicated low heterozygosity, a low polymorphism information content, and a high inbreeding coefficient in the Korean cowpea accessions. The population structure analysis will provide useful knowledge to support the genetic potential of the cowpea breeding program, especially in Korea.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Manosh Kumar Biswas ◽  
Mita Bagchi ◽  
Ujjal Kumar Nath ◽  
Dhiman Biswas ◽  
Sathishkumar Natarajan ◽  
...  

Abstract Lily belongs to family liliaceae, which mainly propagates vegetatively. Therefore, sufficient number of polymorphic, informative, and functional molecular markers are essential for studying a wide range of genetic parameters in Lilium species. We attempted to develop, characterize and design SSR (simple sequence repeat) markers using online genetic resources for analyzing genetic diversity and population structure of Lilium species. We found di-nucleotide repeat motif were more frequent (4684) within 0.14 gb (giga bases) transcriptome than other repeats, of which was two times higher than tetra-repeat motifs. Frequency of di-(AG/CT), tri-(AGG/CTT), tetra-(AAAT), penta-(AGAGG), and hexa-(AGAGGG) repeats was 34.9%, 7.0%, 0.4%, 0.3%, and 0.2%, respectively. A total of 3607 non-redundant SSR primer pairs was designed based on the sequences of CDS, 5′-UTR and 3′-UTR region covering 34%, 14%, 23%, respectively. Among them, a sub set of primers (245 SSR) was validated using polymerase chain reaction (PCR) amplification, of which 167 primers gave expected PCR amplicon and 101 primers showed polymorphism. Each locus contained 2 to 12 alleles on average 0.82 PIC (polymorphic information content) value. A total of 87 lily accessions was subjected to genetic diversity analysis using polymorphic SSRs and found to separate into seven groups with 0.73 to 0.79 heterozygosity. Our data on large scale SSR based genetic diversity and population structure analysis may help to accelerate the breeding programs of lily through utilizing different genomes, understanding genetics and characterizing germplasm with efficient manner.


PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253600
Author(s):  
Charles U. Uba ◽  
Happiness O. Oselebe ◽  
Abush A. Tesfaye ◽  
Wosene G. Abtew

Understanding the genetic structure and diversity of crops facilitates progress in plant breeding. A collection of 270 bambara groundnut (Vigna subterrenea L) landraces sourced from different geographical regions (Nigeria/Cameroon, West, Central, Southern and East Africa) and unknown origin (sourced from United Kingdom) was used to assess genetic diversity, relationship and population structure using DArT SNP markers. The major allele frequency ranged from 0.57 for unknown origin to 0.91 for West Africa region. The total gene diversity (0.482) and Shannon diversity index (0.787) was higher in West African accessions. The genetic distance between pairs of regions varied from 0.002 to 0.028 with higher similarity between Nigeria/Cameroon-West Africa accessions and East-Southern Africa accessions. The analysis of molecular variance (AMOVA) revealed 89% of genetic variation within population, 8% among regions and 3% among population. The genetic relatedness among the collections was evaluated using neighbor joining tree analysis, which grouped all the geographic regions into three major clusters. Three major subgroups of bambara groundnut were identified using the ADMIXTURE model program and confirmed by discriminant analysis of principal components (DAPC). These subgroups were West Africa, Nigeria/Cameroon and unknown origin that gave rise to sub-population one, and Central Africa was sub-population two, while Southern and East Africa were sub-population three. In general, the results of all the different analytical methods used in this study confirmed the existence of high level of diversity among the germplasm used in this study that might be utilized for future genetic improvement of bambara groundnut. The finding also provides new insight on the population structure of African bambara groundnut germplasm which will help in conservation strategy and management of the crop.


2022 ◽  
Author(s):  
Ming Jiang ◽  
Song Yan ◽  
Weichao Ren ◽  
Nannan Xing ◽  
Hongyuan Li ◽  
...  

Abstract Bupleurum (named “Chai-hu”) is an important traditional Chinese medicine resource in China. It has been widely used since ancient times and has antipyretic, analgesic and cholagogic functions, but there is little research on its genetic diversity. In this study, genotyping-by-sequencing (GBS) was used to detect SNP loci in 39 Bupleurum germplasm resources from different regions in China and analyse their genetic diversity. A total of 25.1 Gb of data was obtained by sequencing, with an average of 0.64 Gb per sample. After screening, 83898 high-quality SNPs were obtained. The results of genetic research were obtained by phylogenetic tree, principal component analysis and population structure analysis, and the 39 experimental materials were divided into three groups. The average observed heterozygosity and expected heterozygosity of Bupleurum populations were 0.24 and 0.17, respectively, indicating that Bupleurum populations from five different provinces had a low level of genetic diversity. Population nucleotide diversity analysis and analysis of molecular variance showed that the percentage of intrapopulation variation was 120.88%, while the percentage of interpopulation variation was only 2.46%. There was relative aggregation of Bupleurum samples with the same geographical origin, but the division of population structure was not completely correlated with sample origin. The results showed that the genetic diversity of the materials was low and that the genetic variation was narrow. This provides a good basis for the genetic breeding and protection of species diversity of Bupleurum.


Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1233
Author(s):  
Alemayehu Teressa Negawo ◽  
Meki S. Muktar ◽  
Yilikal Assefa ◽  
Jean Hanson ◽  
Alieu M. Sartie ◽  
...  

Rhodes grass (Chloris gayana Kunth) is one of the most important forage grasses used throughout the tropical and subtropical regions of the world. Enhancing the conservation and use of genetic resources requires the development of knowledge and understanding about the existing global diversity of the species. In this study, 104 Rhodes grass accessions, held in trust in the ILRI forage genebank, were characterized using DArTSeq markers to evaluate the genetic diversity and population structure, and to develop representative subsets, of the collection. The genotyping produced 193,988 SNP and 142,522 SilicoDArT markers with an average polymorphic information content of 0.18 and 0.26, respectively. Hierarchical clustering using selected informative markers showed the presence of two and three main clusters using SNP and SilicoDArT markers, respectively, with a cophenetic correction coefficient of 82%. Bayesian population structure analysis also showed the presence of two main subpopulations using both marker types indicating the existence of significant genetic variation in the collection. A representative subset, containing 21 accessions from diverse origins, was developed using the SNP markers. In general, the results revealed substantial genetic diversity in the Rhodes grass collection, and the generated molecular information, together with the developed subset, should help enhance the management, use and improvement of Rhodes grass germplasm in the future.


Genes ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 676 ◽  
Author(s):  
Farahani ◽  
Maleki ◽  
Mehrabi ◽  
Kanouni ◽  
Scheben ◽  
...  

Characterization of genetic diversity, population structure, and linkage disequilibrium is a prerequisite for proper management of breeding programs and conservation of genetic resources. In this study, 186 chickpea genotypes, including advanced “Kabuli” breeding lines and Iranian landrace “Desi” chickpea genotypes, were genotyped using DArTseq-Based single nucleotide polymorphism (SNP) markers. Out of 3339 SNPs, 1152 markers with known chromosomal position were selected for genome diversity analysis. The number of mapped SNP markers varied from 52 (LG8) to 378 (LG4), with an average of 144 SNPs per linkage group. The chromosome size that was covered by SNPs varied from 16,236.36 kbp (LG8) to 67,923.99 kbp (LG5), while LG4 showed a higher number of SNPs, with an average of 6.56 SNPs per Mbp. Polymorphism information content (PIC) value of SNP markers ranged from 0.05 to 0.50, with an average of 0.32, while the markers on LG4, LG6, and LG8 showed higher mean PIC value than average. Unweighted neighbor joining cluster analysis and Bayesian-based model population structure grouped chickpea genotypes into four distinct clusters. Principal component analysis (PCoA) and discriminant analysis of principal component (DAPC) results were consistent with that of the cluster and population structure analysis. Linkage disequilibrium (LD) was extensive and LD decay in chickpea germplasm was relatively low. A few markers showed r2 ≥ 0.8, while 2961 pairs of markers showed complete LD (r2 = 1), and a huge LD block was observed on LG4. High genetic diversity and low kinship value between pairs of genotypes suggest the presence of a high genetic diversity among the studied chickpea genotypes. This study also demonstrates the efficiency of DArTseq-based SNP genotyping for large-scale genome analysis in chickpea. The genotypic markers provided in this study are useful for various association mapping studies when combined with phenotypic data of different traits, such as seed yield, abiotic, and biotic stresses, and therefore can be efficiently used in breeding programs to improve chickpea.


2021 ◽  
Author(s):  
Maya Peringottillam ◽  
Smitha Kunhiraman Vasumathy ◽  
Hari Krishna Kumar ◽  
Manickavelu Alagu

Abstract Researchers stand at the vanguard of advancement and application of next-generation sequencing technology for creating opportunities to guide more realistic and applicable strategies for the sustainable management of genetically diverse rice resources. This study is a pioneering effort where GBS-SNP markers were employed to assess the tremendous genetic diversity and structure of rice landrace collections from northern Kerala. Kerala holds an immense diversity of rice landraces that encountered selection pressures of environmental heterogeneity, biotic and abiotic stresses, however competent rather provide good yields, whereby drawing the attention of the rice breeding sector. The population structure and diversity analyses separated the accessions into three distinct subpopulations with a huge amount of genetic variation within subpopulations. Nei’s genetic distance analysis confirmed the existence of strong genetic differentiation among rice landrace populations. The values of FST and Nm established the farmers’ effort to preserve the genetic purity of rice landraces despite the extensive seed exchange programs across the states of India. Moreover, this low level of gene flow among subpopulations could provide the opportunity for well-adapted combinations of genes to be established by natural selection. The clustering pattern based on SNP markers furnished sufficient knowledge in identifying rice genotypes that eliminates the likelihood of duplication among indigenous cultivars. Similar clustering patterns of genotypes revealed shared genetic characters among them. Collectively these analyses can be used to completely understand the population of rice landraces in Kerala while contributing insights toward the evolution and selective pressures underlying these unique landraces.


Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1282
Author(s):  
Yu Wang ◽  
Zhongyi Jiao ◽  
Jiwei Zheng ◽  
Jie Zhou ◽  
Baosong Wang ◽  
...  

Chosenia arbutifolia (Pall.) A. Skv. is a unique and endangered species belonging to the Salicaceae family. It has great potential for ornamental and industrial use. However, human interference has led to a decrease in and fragmentation of its natural populations in the past two decades. To effectively evaluate, utilize, and conserve available resources, the genetic diversity and population structure of C. arbutifolia were analyzed in this study. A total of 142 individuals from ten provenances were sampled and sequenced. Moderate diversity was detected among these, with a mean expected heterozygosity and Shannon’s Wiener index of 0.3505 and 0.5258, respectively. The inbreeding coefficient was negative, indicating a significant excess of heterozygotes. The fixation index varied from 0.0068 to 0.3063, showing a varied genetic differentiation between populations. Analysis of molecular variance demonstrated that differentiation accounted for 82.23% of the total variation among individuals, while the remaining 17.77% variation was between populations. Furthermore, the results of population structure analysis indicated that the 142 individuals originated from three primitive groups. To provide genetic information and help design conservation and management strategies, landscape genomics analysis was performed by investigating loci associated with environmental variables. Eighteen SNP markers were associated with altitude and annual average temperature, of which five were ascribed with specific functions. In conclusion, the current study furthers the understanding of C. arbutifolia genetic architecture and provides insights for germplasm protection.


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