The olive complex, comprising six subspecies, is a valuable plant for global trade, human health, and food safety. However, only one subspecies (Olea europaea subsp. europaea, OE) and its wild relative (Olea europaea subsp. europaea var. sylvestris, OS) have genomic references, hindering our understanding of the evolution of this species. Using a hybrid approach by incorporating Illumina, MGI, Nanopore, and Hi-C technologies, we obtained a 1.20-Gb genome assembly for the olive subspecies, Olea europaea subsp. cuspidate (OC), with contig and scaffold N50 values of 5.33 and 50.46 Mb, respectively. A total of 43,511 protein-coding genes were predicted from the genome. Interestingly, we observed a large region (37.5 Mb) of “gene-desert” also called “LTR-hotspot” on chromosome 17. The gene origination analyses revealed a substantial outburst (19.5%) of gene transposition events in the common ancestor of olive subspecies, suggesting the importance of olive speciation in shaping the new gene evolution of OC subspecies. The divergence time between OC and the last common ancestor of OE and OS was estimated to be 4.39 Mya (95% CI: 2.58–6.23 Mya). The pathways of positively selected genes of OC are related to the metabolism of cofactors and vitamins, indicating the potential medical and economic values of OC for further research and utilization. In summary, we constructed the de novo genome assembly and protein-coding gene pool for Olea europaea subsp. cuspidate (OC) in this study, which may facilitate breeding applications of improved olive varieties from this widely distributed olive close relative.

Chimonobambusa angustifolia is a famous ornamental and edible bamboo species. Here, the complete chloroplast (cp) genome of C. angustifolia was assembled and annotated. The cp genome is 139,611 bp in size, consisting of two copies of inverted repeat (IR) regions of 21,799 bp, one large single-copy (LSC) region of 83,202 bp, and one small single-copy (SSC) region of 12,811 bp. It encodes 133 genes (110 unique), including 86 protein-coding genes (77 unique), 39 tRNA genes (29 unique), and 8 rRNA genes (4 unique). Phylogenetic analysis based on 21 cp genome sequences within four genera of family Poaceae indicated that genus Chimonobambusa were closely related to genus Shibataea, both belong to subtribe Shlbataeinae.

Background: Sichuan Dark Tea is a popular beverage with hypolipidemic and lifting greasy properties in the minority neighborhoods of Sichuan and Tibet regions. The theabrownin, an important pigment of dark tea, has been proven for the role of the hypolipidemic property in Sichuan Dark Tea. The objective of the study investigated the extraction process of theabrownin. Materials and Methods: Theabrownin was extracted from Sichuan Dark Tea with water and organic solvents. The quadratic regression orthogonally rotational combinational design experiment was performed to obtain the optimal extraction parameters. Results: The extraction yield of theabrownin was significantly influenced by both water extraction temperature and solid-liquid ratio, and the contribution of these factors on theabrownin yield was as follows: water temperature﹥solid-liquid ratio﹥organic solvent temperature. Moreover, the polynomial regression model established could predict the experimental value accurately. Conclusion: The optimum extraction process of theabrownin from Sichuan Dark Tea was established, which water temperature at 65.69-77.88℃, organic solvent temperature at 13.65-17.48℃ and a solid-liquid ratio of 1:43.58-1:50.75(g/mL).

The whole chloroplast (cp) genome sequence of Chimonobambusa utilis (Keng) P. C. Keng has been characterized using Illumina pair-end sequencing. The complete cp genome (GenBank accession: OK040769) was 139,540 bp in length, containing a large single copy region (LSC) of 83,133 bp and a small single copy region (SSC) of 12,811 bp, which were separated by a pair of 21,798 bp inverted repeat regions (IRs). The genome contained 133 genes (114 unique), including 86 protein-coding genes (81 unique), 39 tRNA genes (29 unique), and eight rRNA genes (four unique). The overall GC content of C. utilis cp genome is 38.88%. Phylogenetic analysis of 32 cp genomes within the supertribe Bambusatae suggests that C. utilis is closely related to C. quadrangularis.