AUTHOR=Xu Jin , Liu Chen , Song Yun , Li Mingfu 

TITLE=Comparative Analysis of the Chloroplast Genome for Four Pennisetum Species: Molecular Structure and Phylogenetic Relationships

JOURNAL=Frontiers in Genetics

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2021.687844

DOI=10.3389/fgene.2021.687844

ISSN=1664-8021

ABSTRACT=<p>The genus <italic>Pennisetum</italic> (Poaceae) is both a forage crop and staple food crop in the tropics. In this study, we obtained chloroplast genome sequences of four species of <italic>Pennisetum</italic> (<italic>P. alopecuroides</italic>, <italic>P. clandestinum</italic>, <italic>P. glaucum</italic>, and <italic>P. polystachion</italic>) using Illumina sequencing. These chloroplast genomes have circular structures of 136,346–138,119 bp, including a large single-copy region (LSC, 79,380–81,186 bp), a small single-copy region (SSC, 12,212–12,409 bp), and a pair of inverted repeat regions (IRs, 22,284–22,372 bp). The overall GC content of these chloroplast genomes was 38.6–38.7%. The complete chloroplast genomes contained 110 different genes, including 76 protein-coding genes, 30 transfer RNA (tRNA) genes, and four ribosomal RNA (rRNA) genes. Comparative analysis of nucleotide variability identified nine intergenic spacer regions (<italic>psbA-matK, matK-rps16, trnN-trnT, trnY-trnD-psbM, petN-trnC, rbcL-psaI, petA-psbJ, psbE-petL</italic>, and <italic>rpl32-trnL</italic>), which may be used as potential DNA barcodes in future species identification and evolutionary analysis of <italic>Pennisetum</italic>. The phylogenetic analysis revealed a close relationship between <italic>P. polystachion</italic> and <italic>P. glaucum</italic>, followed by <italic>P. clandestinum</italic> and <italic>P. alopecuroides</italic>. The completed genomes of this study will help facilitate future research on the phylogenetic relationships and evolution of <italic>Pennisetum</italic> species.</p>