Chloroplast genome sequences from total DNA for plant identification.

Chloroplast DNA sequence data are a versatile tool for plant identification or barcoding and establishing genetic relationships among plant species. Different chloroplast loci have been utilized for use at close and distant evolutionary distances in plants, and no single locus has been identified that can distinguish between all plant species. Advances in DNA sequencing technology are providing new cost-effective options for genome comparisons on a much larger scale. Universal PCR amplification of chloroplast sequences or isolation of pure chloroplast fractions, however, are non-trivial. We now propose the analysis of chloroplast genome sequences from massively parallel sequencing (MPS) of total DNA as a simple and cost-effective option for plant barcoding, and analysis of plant relationships to guide gene discovery for biotechnology. We present chloroplast genome sequences of five grass species derived from MPS of total DNA. These data accurately established the phylogenetic relationships between the species, correcting an apparent error in the published rice sequence. The chloroplast genome may be the elusive single-locus DNA barcode for plants.