OBJECTIVE: To study the optimum technique for extraction of mixture volatile oil from Olibanam and Sandalwood. METHODS: The orthogonal test was adopted to optimize the extraction process using the yield rate of volatile oil as indicator. RESULTS: The optimum extraction conditions were as follows: powder forming by 10mesh, 10- fold water added, soaking for 10h and extraction for 8h. CONCLUSIONS: This extraction method is simple, efficient and suitable for industria-lized production.

Malus floribunda Siebold. (Malus) is widely cultivated all over the world, which is of high ornamental value and breeding significance. Comparative analysis of the chloroplast genome can help enrich the phylogenetic relationship and facilitate germplasm utilization of Malus. Based on the whole genome sequencing data, a complete chloroplast genome (M. floribunda) with tetrad structure was assembled. The chloroplast genome (160 037 bp) was composed of a large single-copy (LSC) region (88 142 bp), inverted repeat (IR) B (26 353 bp), a small single-copy (SSC) region (19 189 bp), and IRA (26 353 bp). A total of 111 genes were annotated: 78 protein-coding genes, 29 tRNA genes and 4 rRNA genes. In addition, a large number of repeat sequences were identified in the genome, which was slightly different from that of M. sieboldii and M. toringoides. As for the relative synonymous codon usage, 30 high-frequency codons were found, and the codons tended to end with A/T. The results of interspecific sequence alignment and boundary analysis suggested the sequence variation of the LSC region was large, and the expansion and contraction of the SC region and IR region of the eight Malus species were generally similar. According to the phylogenetic analysis of chloroplast genome sequences, M. floribunda, M. hupehensis, and M. toringoides were grouped into one clade. The findings in this study can provide data support for the development of genetic markers and utilization of germplasm resources in the future.
Genome, Chloroplast ; Malus ; Phylogeny ; Plant Breeding ; Codon