scholarly journals The use of next generation sequencing to solve phylogenetic incongruences in Orchidaceae Juss

Author(s):  
Narjara Lopes de Abreu ◽  
Ruy José Válka Alves ◽  
Sérgio Ricardo Sodré Cardoso ◽  
Yann JK Bertrand ◽  
Filipe Sousa ◽  
...  

Background. Current evidence suggests that for more robust estimates of species tree and divergence times, several unlinked genes are required. However, most phylogenetic trees for non-model organisms are based on single sequences or just a few regions, using traditional sequencing methods. Techniques for massive parallel sequencing or Next Generation Sequencing are an alternative to traditional methods that allow access to hundreds of DNA regions. Here we use this approach to resolve the phylogenetic incongruence found in Polystachya Hook. (Orchidaceae), a genus that stands out due to several interesting aspects, including cytological (polyploid and diploid species), evolutionary (reticulate evolution) and biogeographical (species widely distributed in the tropics and high endemism in Brazil). The genus has a notoriously complicated taxonomy, with several sections that are widely used but probably not monophyletic. Methods. We generated the complete chloroplast genome of 48 individuals from one clade within the genus. The method consisted in construction of genomic libraries, hybridization to RNA probes designed from available sequences of a related species, and subsequent sequencing of the product. We also tested how well a smaller sample of the chloroplast genome would perform in phylogenetic inference in two ways: by duplicating a fast region and analysing multiple copies of this dataset, and by sampling without replacement from all non-coding regions in our alignment. We further examined the phylogenetic implications of non-coding sequences that appear to have undergone hairpin inversions (reverse complemented sequences associated with small loops). Results. We retrieved 131,214 bp, including coding and non-coding regions of the chloroplast genome. The phylogeny was able to fully resolve the relationships among all species in the targeted clade with high support values. The first divergent species are represented by African accessions and the most recent ones are among Neotropical species. Discussion. Our results indicate that using the entire chloroplast is a better option than screening highly variable markers, especially when the expected tree is likely to contain many short branches. The phylogeny inferred is consistent with the proposed origin of the genus, showing a probable origin in Africa, with later dispersal into the Neotropics, as evidenced by a clade containing all Neotropical individuals. The multiple positions of Polystachya concreta (Jacq.) Garay & Sweet in the phylogeny are explained by allotetraploidy. Polystachya estrellensis Rchb.f. can be considered a genetically distinct species from P. concreta and P. foliosa (Lindl.) Rchb.f., but the delimitation of P. concreta remains uncertain. Our study shows that next generation sequencing provides a powerful tool for inferring relationships at low taxonomic levels, even in taxonomically challenging groups with short branches and intricate morphology.

2018 ◽  
Author(s):  
Narjara Lopes de Abreu ◽  
Ruy José Válka Alves ◽  
Sérgio Ricardo Sodré Cardoso ◽  
Yann JK Bertrand ◽  
Filipe Sousa ◽  
...  

Background. Current evidence suggests that for more robust estimates of species tree and divergence times, several unlinked genes are required. However, most phylogenetic trees for non-model organisms are based on single sequences or just a few regions, using traditional sequencing methods. Techniques for massive parallel sequencing or Next Generation Sequencing are an alternative to traditional methods that allow access to hundreds of DNA regions. Here we use this approach to resolve the phylogenetic incongruence found in Polystachya Hook. (Orchidaceae), a genus that stands out due to several interesting aspects, including cytological (polyploid and diploid species), evolutionary (reticulate evolution) and biogeographical (species widely distributed in the tropics and high endemism in Brazil). The genus has a notoriously complicated taxonomy, with several sections that are widely used but probably not monophyletic. Methods. We generated the complete chloroplast genome of 48 individuals from one clade within the genus. The method consisted in construction of genomic libraries, hybridization to RNA probes designed from available sequences of a related species, and subsequent sequencing of the product. We also tested how well a smaller sample of the chloroplast genome would perform in phylogenetic inference in two ways: by duplicating a fast region and analysing multiple copies of this dataset, and by sampling without replacement from all non-coding regions in our alignment. We further examined the phylogenetic implications of non-coding sequences that appear to have undergone hairpin inversions (reverse complemented sequences associated with small loops). Results. We retrieved 131,214 bp, including coding and non-coding regions of the chloroplast genome. The phylogeny was able to fully resolve the relationships among all species in the targeted clade with high support values. The first divergent species are represented by African accessions and the most recent ones are among Neotropical species. Discussion. Our results indicate that using the entire chloroplast is a better option than screening highly variable markers, especially when the expected tree is likely to contain many short branches. The phylogeny inferred is consistent with the proposed origin of the genus, showing a probable origin in Africa, with later dispersal into the Neotropics, as evidenced by a clade containing all Neotropical individuals. The multiple positions of Polystachya concreta (Jacq.) Garay & Sweet in the phylogeny are explained by allotetraploidy. Polystachya estrellensis Rchb.f. can be considered a genetically distinct species from P. concreta and P. foliosa (Lindl.) Rchb.f., but the delimitation of P. concreta remains uncertain. Our study shows that next generation sequencing provides a powerful tool for inferring relationships at low taxonomic levels, even in taxonomically challenging groups with short branches and intricate morphology.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4916 ◽  
Author(s):  
Narjara Lopes de Abreu ◽  
Ruy José Válka Alves ◽  
Sérgio Ricardo Sodré Cardoso ◽  
Yann J.K. Bertrand ◽  
Filipe Sousa ◽  
...  

BackgroundCurrent evidence suggests that for more robust estimates of species tree and divergence times, several unlinked genes are required. However, most phylogenetic trees for non-model organisms are based on single sequences or just a few regions, using traditional sequencing methods. Techniques for massive parallel sequencing or next generation sequencing (NGS) are an alternative to traditional methods that allow access to hundreds of DNA regions. Here we use this approach to resolve the phylogenetic incongruence found inPolystachyaHook. (Orchidaceae), a genus that stands out due to several interesting aspects, including cytological (polyploid and diploid species), evolutionary (reticulate evolution) and biogeographical (species widely distributed in the tropics and high endemism in Brazil). The genus has a notoriously complicated taxonomy, with several sections that are widely used but probably not monophyletic.MethodsWe generated the complete plastid genome of 40 individuals from one clade within the genus. The method consisted in construction of genomic libraries, hybridization to RNA probes designed from available sequences of a related species, and subsequent sequencing of the product. We also tested how well a smaller sample of the plastid genome would perform in phylogenetic inference in two ways: by duplicating a fast region and analyzing multiple copies of this dataset, and by sampling without replacement from all non-coding regions in our alignment. We further examined the phylogenetic implications of non-coding sequences that appear to have undergone hairpin inversions (reverse complemented sequences associated with small loops).ResultsWe retrieved 131,214 bp, including coding and non-coding regions of the plastid genome. The phylogeny was able to fully resolve the relationships among all species in the targeted clade with high support values. The first divergent species are represented by African accessions and the most recent ones are among Neotropical species.DiscussionOur results indicate that using the entire plastid genome is a better option than screening highly variable markers, especially when the expected tree is likely to contain many short branches. The phylogeny inferred is consistent with the proposed origin of the genus, showing a probable origin in Africa, with later dispersal into the Neotropics, as evidenced by a clade containing all Neotropical individuals. The multiple positions ofPolystachya concreta(Jacq.) Garay & Sweet in the phylogeny are explained by allotetraploidy.Polystachya estrellensisRchb.f. can be considered a genetically distinct species fromP. concretaandP. foliosa(Lindl.) Rchb.f., but the delimitation ofP. concretaremains uncertain. Our study shows that NGS provides a powerful tool for inferring relationships at low taxonomic levels, even in taxonomically challenging groups with short branches and intricate morphology.


2018 ◽  
Vol 4 (1) ◽  
pp. 29-30
Author(s):  
Yi-Zhen Shao ◽  
Yun Chen ◽  
Xiao-Fang Lu ◽  
Yong-Zhong Ye ◽  
Zhi-Liang Yuan

2021 ◽  
Author(s):  
Marcia Gumiel ◽  
Oscar M Rollano-Penaloza ◽  
Carmelo Peralta-Rivero ◽  
Leslie Tejeda ◽  
Valeria D. Palma Encinas ◽  
...  

We report the complete chloroplast sequences of two varieties of Theobroma cacao collected in the Bolivian Amazonia using Next-Generation Sequencing. Comparisons made between these two chloroplast genomes and the Belizean reference plastid genome identified 19 and 22 nucleotide variants. The phylogenetic analysis reported three main T. cacao clades belonging to the Forastero, Criollo and Trinitario groups. The Bolivian Native Cacao varieties were located inside the Trinitario group forming their unique branch. The Bolivian Native Cacao branch reveals a possible new subpopulation different from the well-characterized T. cacao subpopulations. The phylogenetic trees showed that the relationships among the T. cacao varieties were consistent with their geographical locations placing the Cacao Center of Origin in Western Amazon. The data presented here will contribute to the usage of ultrabarcoding to distinguish different T. cacao varieties and to identify native cacaos from introduced cacaos. Thus helping in the conservation of local native varieties of T. cacao.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6563
Author(s):  
Jianying Sun ◽  
Xiaofeng Dong ◽  
Qinghe Cao ◽  
Tao Xu ◽  
Mingku Zhu ◽  
...  

Background Ipomoea is the largest genus in the family Convolvulaceae. The species in this genus have been widely used in many fields, such as agriculture, nutrition, and medicine. With the development of next-generation sequencing, more than 50 chloroplast genomes of Ipomoea species have been sequenced. However, the repeats and divergence regions in Ipomoea have not been well investigated. In the present study, we sequenced and assembled eight chloroplast genomes from sweet potato’s close wild relatives. By combining these with 32 published chloroplast genomes, we conducted a detailed comparative analysis of a broad range of Ipomoea species. Methods Eight chloroplast genomes were assembled using short DNA sequences generated by next-generation sequencing technology. By combining these chloroplast genomes with 32 other published Ipomoea chloroplast genomes downloaded from GenBank and the Oxford Research Archive, we conducted a comparative analysis of the repeat sequences and divergence regions across the Ipomoea genus. In addition, separate analyses of the Batatas group and Quamoclit group were also performed. Results The eight newly sequenced chloroplast genomes ranged from 161,225 to 161,721 bp in length and displayed the typical circular quadripartite structure, consisting of a pair of inverted repeat (IR) regions (30,798–30,910 bp each) separated by a large single copy (LSC) region (87,575–88,004 bp) and a small single copy (SSC) region (12,018–12,051 bp). The average guanine-cytosine (GC) content was approximately 40.5% in the IR region, 36.1% in the LSC region, 32.2% in the SSC regions, and 37.5% in complete sequence for all the generated plastomes. The eight chloroplast genome sequences from this study included 80 protein-coding genes, four rRNAs (rrn23, rrn16, rrn5, and rrn4.5), and 37 tRNAs. The boundaries of single copy regions and IR regions were highly conserved in the eight chloroplast genomes. In Ipomoea, 57–89 pairs of repetitive sequences and 39–64 simple sequence repeats were found. By conducting a sliding window analysis, we found six relatively high variable regions (ndhA intron, ndhH-ndhF, ndhF-rpl32, rpl32-trnL, rps16-trnQ, and ndhF) in the Ipomoea genus, eight (trnG, rpl32-trnL, ndhA intron, ndhF-rpl32, ndhH-ndhF, ccsA-ndhD, trnG-trnR, and pasA-ycf3) in the Batatas group, and eight (ndhA intron, petN-psbM, rpl32-trnL, trnG-trnR, trnK-rps16, ndhC-trnV, rps16-trnQ, and trnG) in the Quamoclit group. Our maximum-likelihood tree based on whole chloroplast genomes confirmed the phylogenetic topology reported in previous studies. Conclusions The chloroplast genome sequence and structure were highly conserved in the eight newly-sequenced Ipomoea species. Our comparative analysis included a broad range of Ipomoea chloroplast genomes, providing valuable information for Ipomoea species identification and enhancing the understanding of Ipomoea genetic resources.


Viruses ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 701 ◽  
Author(s):  
Kumar ◽  
Chaudhary ◽  
Lu ◽  
Duff ◽  
Heffel ◽  
...  

Viruses belonging to the genus Bocaparvovirus (BoV) are a genetically diverse group of DNA viruses known to cause respiratory, enteric, and neurological diseases in animals, including humans. An intestinal sample from an alpaca (Vicugna pacos) herd with reoccurring diarrhea and respiratory disease was submitted for next-generation sequencing, revealing the presence of a BoV strain. The alpaca BoV strain (AlBoV) had a 58.58% whole genome nucleotide percent identity to a camel BoV from Dubai, belonging to a tentative ungulate BoV 8 species (UBoV8). Recombination events were lacking with other UBoV strains. The AlBoV genome was comprised of the NS1, NP1, and VP1 proteins. The NS1 protein had the highest amino acid percent identity range (57.89–67.85%) to the members of UBoV8, which was below the 85% cut-off set by the International Committee on Taxonomy of Viruses. The low NS1 amino acid identity suggests that AlBoV is a tentative new species. The whole genome, NS1, NP1, and VP1 phylogenetic trees illustrated distinct branching of AlBoV, sharing a common ancestor with UBoV8. Walker loop and Phospholipase A2 (PLA2) motifs that are vital for virus infectivity were identified in NS1 and VP1 proteins, respectively. Our study reports a novel BoV strain in an alpaca intestinal sample and highlights the need for additional BoV research.


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