scholarly journals Species Identification of Oaks (Quercus L., Fagaceae) from Gene to Genome

2019 ◽  
Vol 20 (23) ◽  
pp. 5940
Author(s):  
Xinbo Pang ◽  
Hongshan Liu ◽  
Suran Wu ◽  
Yangchen Yuan ◽  
Haijun Li ◽  
...  

Species identification of oaks (Quercus) is always a challenge because many species exhibit variable phenotypes that overlap with other species. Oaks are notorious for interspecific hybridization and introgression, and complex speciation patterns involving incomplete lineage sorting. Therefore, accurately identifying Quercus species barcodes has been unsuccessful. In this study, we used chloroplast genome sequence data to identify molecular markers for oak species identification. Using next generation sequencing methods, we sequenced 14 chloroplast genomes of Quercus species in this study and added 10 additional chloroplast genome sequences from GenBank to develop a DNA barcode for oaks. Chloroplast genome sequence divergence was low. We identified four mutation hotspots as candidate Quercus DNA barcodes; two intergenic regions (matK-trnK-rps16 and trnR-atpA) were located in the large single copy region, and two coding regions (ndhF and ycf1b) were located in the small single copy region. The standard plant DNA barcode (rbcL and matK) had lower variability than that of the newly identified markers. Our data provide complete chloroplast genome sequences that improve the phylogenetic resolution and species level discrimination of Quercus. This study demonstrates that the complete chloroplast genome can substantially increase species discriminatory power and resolve phylogenetic relationships in plants.

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 474 ◽  
Author(s):  
Dong-Mei Li ◽  
Chao-Yi Zhao ◽  
Xiao-Fei Liu

Kaempferia galanga and Kaempferia elegans, which belong to the genus Kaempferia family Zingiberaceae, are used as valuable herbal medicine and ornamental plants, respectively. The chloroplast genomes have been used for molecular markers, species identification and phylogenetic studies. In this study, the complete chloroplast genome sequences of K. galanga and K. elegans are reported. Results show that the complete chloroplast genome of K. galanga is 163,811 bp long, having a quadripartite structure with large single copy (LSC) of 88,405 bp and a small single copy (SSC) of 15,812 bp separated by inverted repeats (IRs) of 29,797 bp. Similarly, the complete chloroplast genome of K. elegans is 163,555 bp long, having a quadripartite structure in which IRs of 29,773 bp length separates 88,020 bp of LSC and 15,989 bp of SSC. A total of 111 genes in K. galanga and 113 genes in K. elegans comprised 79 protein-coding genes and 4 ribosomal RNA (rRNA) genes, as well as 28 and 30 transfer RNA (tRNA) genes in K. galanga and K. elegans, respectively. The gene order, GC content and orientation of the two Kaempferia chloroplast genomes exhibited high similarity. The location and distribution of simple sequence repeats (SSRs) and long repeat sequences were determined. Eight highly variable regions between the two Kaempferia species were identified and 643 mutation events, including 536 single-nucleotide polymorphisms (SNPs) and 107 insertion/deletions (indels), were accurately located. Sequence divergences of the whole chloroplast genomes were calculated among related Zingiberaceae species. The phylogenetic analysis based on SNPs among eleven species strongly supported that K. galanga and K. elegans formed a cluster within Zingiberaceae. This study identified the unique characteristics of the entire K. galanga and K. elegans chloroplast genomes that contribute to our understanding of the chloroplast DNA evolution within Zingiberaceae species. It provides valuable information for phylogenetic analysis and species identification within genus Kaempferia.


2017 ◽  
Vol 5 (47) ◽  
Author(s):  
Aisuo Wang ◽  
Hanwen Wu ◽  
David Gopurenko

ABSTRACT Nassella hyalina (cane needle grass) is on the Alert List for Environmental Weeds in Australia. We present here the first complete chloroplast sequence of N. hyalina reconstructed from Illumina whole-genome sequencing. The complete chloroplast sequence is 137,606 bp in size and has a gene content and structure similar to those of other published chloroplast genomes of Stipeae.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6032 ◽  
Author(s):  
Zhenyu Zhao ◽  
Xin Wang ◽  
Yi Yu ◽  
Subo Yuan ◽  
Dan Jiang ◽  
...  

Dioscorea L., the largest genus of the family Dioscoreaceae with over 600 species, is not only an important food but also a medicinal plant. The identification and classification of Dioscorea L. is a rather difficult task. In this study, we sequenced five Dioscorea chloroplast genomes, and analyzed with four other chloroplast genomes of Dioscorea species from GenBank. The Dioscorea chloroplast genomes displayed the typical quadripartite structure of angiosperms, which consisted of a pair of inverted repeats separated by a large single-copy region, and a small single-copy region. The location and distribution of repeat sequences and microsatellites were determined, and the rapidly evolving chloroplast genome regions (trnK-trnQ, trnS-trnG, trnC-petN, trnE-trnT, petG-trnW-trnP, ndhF, trnL-rpl32, and ycf1) were detected. Phylogenetic relationships of Dioscorea inferred from chloroplast genomes obtained high support even in shortest internodes. Thus, chloroplast genome sequences provide potential molecular markers and genomic resources for phylogeny and species identification.


Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1405
Author(s):  
Gurusamy Raman ◽  
SeonJoo Park

The plant “False Lily of the Valley”, Speirantha gardenii is restricted to south-east China and considered as an endemic plant. Due to its limited availability, this plant was less studied. Hence, this study is focused on its molecular studies, where we have sequenced the complete chloroplast genome of S. gardenii and this is the first report on the chloroplast genome sequence of Speirantha. The complete S. gardenii chloroplast genome is of 156,869 bp in length with 37.6% GC, which included a pair of inverted repeats (IRs) each of 26,437 bp that separated a large single-copy (LSC) region of 85,368 bp and a small single-copy (SSC) region of 18,627 bp. The chloroplast genome comprises 81 protein-coding genes, 30 tRNA and four rRNA unique genes. Furthermore, a total of 699 repeats and 805 simple-sequence repeats (SSRs) markers are identified in the genome. Additionally, KA/KS nucleotide substitution analysis showed that seven protein-coding genes have highly diverged and identified nine amino acid sites under potentially positive selection in these genes. Phylogenetic analyses suggest that S. gardenii species has a closer genetic relationship to the Reineckea, Rohdea and Convallaria genera. The present study will provide insights into developing a lineage-specific marker for genetic diversity and gene evolution studies in the Nolinoideae taxa.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Junling Cao ◽  
Dan Jiang ◽  
Zhenyu Zhao ◽  
Subo Yuan ◽  
Yujun Zhang ◽  
...  

Chinese yam has been used both as a food and in traditional herbal medicine. Developing more effective genetic markers in this species is necessary to assess its genetic diversity and perform cultivar identification. In this study, new chloroplast genomic resources were developed using whole chloroplast genomes from six genotypes originating from different geographical locations. The Dioscorea polystachya chloroplast genome is a circular molecule consisting of two single-copy regions separated by a pair of inverted repeats. Comparative analyses of six D. polystachya chloroplast genomes revealed 141 single nucleotide polymorphisms (SNPs). Seventy simple sequence repeats (SSRs) were found in the six genotypes, including 24 polymorphic SSRs. Forty-three common indels and five small inversions were detected. Phylogenetic analysis based on the complete chloroplast genome provided the best resolution among the genotypes. Our evaluation of chloroplast genome resources among these genotypes led us to consider the complete chloroplast genome sequence of D. polystachya as a source of reliable and valuable molecular markers for revealing biogeographical structure and the extent of genetic variation in wild populations and for identifying different cultivars.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6244 ◽  
Author(s):  
Simon Pfanzelt ◽  
Dirk C. Albach ◽  
K. Bernhard von Hagen

Astelia pumila (G.Forst.) Gaudich. (Asteliaceae, Asparagales) is a major element of West Patagonian cushion peat bog vegetation. With the aim to identify appropriate chloroplast markers for the use in a phylogeographic study, the complete chloroplast genomes of five A. pumila accessions from almost the entire geographical range of the species were assembled and screened for variable positions. The chloroplast genome sequence was obtained via a mapping approach, using Eustrephus latifolius (Asparagaceae) as a reference. The chloroplast genome of A. pumila varies in length from 158,215 bp to 158,221 bp, containing a large single copy region of 85,981–85,983 bp, a small single copy region of 18,182–18,186 bp and two inverted repeats of 27,026 bp. Genome annotation predicted a total of 113 genes, including 30 tRNA and four rRNA genes. Sequence comparisons revealed a very low degree of intraspecific genetic variability, as only 37 variable sites (18 indels, 18 single nucleotide polymorphisms, one 3-bp mutation)—most of them autapomorphies—were found among the five assembled chloroplast genomes. A Maximum Likelihood analysis, based on whole chloroplast genome sequences of several Asparagales accessions representing six of the currently recognized 14 families (sensu APG IV), confirmed the phylogenetic position of A. pumila. The chloroplast genome of A. pumila is the first to be reported for a member of the astelioid clade (14 genera with c. 215 species), a basally branching group within Asparagales.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yike Luo ◽  
Jian He ◽  
Rudan Lyu ◽  
Jiamin Xiao ◽  
Wenhe Li ◽  
...  

The evening primrose family, Onagraceae, is a well defined family of the order Myrtales, comprising 22 genera widely distributed from boreal to tropical areas. In this study, we report and characterize the complete chloroplast genome sequences of 13 species in Circaea, Chamaenerion, and Epilobium using a next-generation sequencing method. We also retrieved chloroplast sequences from two other Onagraceae genera to characterize the chloroplast genome of the family. The complete chloroplast genomes of Onagraceae encoded an identical set of 112 genes (with exclusion of duplication), including 78 protein-coding genes, 30 transfer RNAs, and four ribosomal RNAs. The chloroplast genomes are basically conserved in gene arrangement across the family. However, a large segment of inversion was detected in the large single copy region of all the samples of Oenothera subsect. Oenothera. Two kinds of inverted repeat (IR) region expansion were found in Oenothera, Chamaenerion, and Epilobium samples. We also compared chloroplast genomes across the Onagraceae samples in some features, including nucleotide content, codon usage, RNA editing sites, and simple sequence repeats (SSRs). Phylogeny was inferred by the chloroplast genome data using maximum-likelihood (ML) and Bayesian inference methods. The generic relationship of Onagraceae was well resolved by the complete chloroplast genome sequences, showing potential value in inferring phylogeny within the family. Phylogenetic relationship in Oenothera was better resolved than other densely sampled genera, such as Circaea and Epilobium. Chloroplast genomes of Oenothera subsect. Oenothera, which are biparental inheritated, share a syndrome of characteristics that deviate from primitive pattern of the family, including slightly expanded inverted repeat region, intron loss in clpP, and presence of the inversion.


Diversity ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 405
Author(s):  
Wei Ren ◽  
Dongquan Guo ◽  
Guojie Xing ◽  
Chunming Yang ◽  
Yuanyu Zhang ◽  
...  

Cyperus esculentus produces large amounts of oil as one of the main oil storage reserves in underground tubers, making this crop species not only a promising resource for edible oil and biofuel in food and chemical industry, but also a model system for studying oil accumulation in non-seed tissues. In this study, we determined the chloroplast genome sequence of the cultivated C. esculentus (var. sativus Boeckeler). The results showed that the complete chloroplast genome of C. esculentus was 186,255 bp in size, and possessed a typical quadripartite structure containing one large single copy (100,940 bp) region, one small single copy (10,439 bp) region, and a pair of inverted repeat regions of 37,438 bp in size. Sequence analyses indicated that the chloroplast genome encodes 141 genes, including 93 protein-coding genes, 40 transfer RNA genes, and 8 ribosomal RNA genes. We also identified 396 simple-sequence repeats and 49 long repeats, including 15 forward repeats and 34 palindromes within the chloroplast genome of C. esculentus. Most of these repeats were distributed in the noncoding regions. Whole chloroplast genome comparison with those of the other four Cyperus species indicated that both the large single copy and inverted repeat regions were more divergent than the small single copy region, with the highest variation found in the inverted repeat regions. In the phylogenetic trees based on the complete chloroplast genomes of 13 species, all five Cyperus species within the Cyperaceae formed a clade, and C. esculentus was evolutionarily more related to C. rotundus than to the other three Cyperus species. In summary, the chloroplast genome sequence of the cultivated C. esculentus provides a valuable genomic resource for species identification, evolution, and comparative genomic research on this crop species and other Cyperus species in the Cyperaceae family.


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