The complete chloroplast genome of Cinnamomum camphora (L.) Presl., a unique economic plant to China

The chloroplast genome of a subtropical tree Sassafras randaiense (Hayata) Rehder, 1920 (Lauraceae)

The complete chloroplast genome sequence of Sassafras randaiense (Hayata) Rehder, 1920, a subtropical tree in the family Lauraceae, was determined. For a better understanding of the differences between S. randaiense and S. tzumu, the complete chloroplast genome of S. randaiense was sequenced and analyzed. The complete chloroplast genome is 151,781 bp in length, consisting of a pair of inverted repeat (IR) regions of 20,114 bp, one large single-copy (LSC) region of 92,740 bp, and one small single-copy (SSC) region of 18,813 bp. The overall GC content of the complete chloroplast genome is 39.2%. Further, maximum-likelihood phylogenetic analysis was conducted using 31 complete plastome sequences, which support that S. randaiense and S. tzumu are nested among the members of Cinnamomum, suggesting that Sassafras belongs to Cinnamomum.

Nuclear Magnetic Resonance Fingerprints and Mini DNA Markers for the Authentication of Cinnamon Species Ingredients Used in Food and Natural Health Products

Cinnamomum verum (syn C. zeylanicum) is considered 'true' cinnamon. However, it is reported that less expensive sources of cinnamon from C. cassia (syn C. aromaticum), C. loureiroi, and C. burmannii (toxic coumarin) may be used in the place of C. verum. We lack the quality assurance tools that are required to differentiate C. verum from other cinnamon species when verifying that the correct species is sourced from ingredient suppliers. The current research on cinnamon species authentication using DNA tools is limited to a few species and the use of high-quality DNA extracted from raw leaf materials. The cinnamon bark traded in the supply chain contains much less DNA and poorer-quality DNA than leaves. Our research advances DNA methods to authenticate cinnamon, as we utilized full-length chloroplast genomes via a genome skimming approach for C. burmannii and C. cassia to facilitate the design of optimal mini DNA markers. Furthermore, we developed and validated the use of NMR fingerprints for several commercial cinnamon species, including the quantification of 16 molecules. NMR fingerprints provided additional data that were useful for quality assessment in cinnamon extract powders and product consistency. Both the new mini DNA markers and NMR fingerprints were tested on commercial cinnamon products.

The chloroplast genome of black pepper (Piper nigrum L.) and its comparative analysis with related Piper species

Piper nigrum, also known as black pepper, is an economically and ecologically important crop of the genus Piper. It has been titled as the king of spices due to its wide consumption throughout the world. In the present investigation, the chloroplast genome of P. nigrum has been assembled from a whole genome sequence by integrating the short and long reads generated through Illumina and PacBio platforms, respectively. The chloroplast genome was observed to be 161,522 bp in size, having a quadripartite structure with a large single copy (LSC) region of 89,153 bp and a small single copy (SSC) region of 18,255 bp separated by a copy of inverted repeats (IRs), each 27,057 bp in length. Taking into consideration all the duplicated genes, a total of 131 genes were observed, which included 81 protein-coding genes, 37 tRNAs, 4 rRNAs, and 1 pseudogene. Individually, the LSC region consisted of 83 genes, the SSC region had 13 genes, and 18 genes were present in each IR region. Additionally, 216 SSRs were detected and 11 of these were validated through amplification in 12 species of Piper. The features of the chloroplast genome have been compared with those of the genus Piper. Our results provide useful insights into evolutionary and molecular studies of black pepper which will contribute to its further genetic improvement and breeding.