Zai-Hua Wang

Abelmoschus is an economically and phylogenetically valuable genus in the family Malvaceae. Owing to coexistence of wild and cultivated form and interspecific hybridization, this genus is controversial in systematics and taxonomy and requires detailed investigation. Here, we present whole chloroplast genome sequences and annotation of three important species: A. moschatus, A. manihot and A. sagittifolius, and compared with A. esculentus published previously. These chloroplast genome sequences ranged from 163121 bp to 163453 bp in length and contained 132 genes with 87 protein-coding genes, 37 transfer RNA and 8 ribosomal RNA genes. Comparative analyses revealed that amino acid frequency and codon usage had similarity among four species, while the number of repeat sequences in A. esculentus were much lower than other three species. Six categories of simple sequence repeats (SSRs) were detected, but A. moschatus and A. manihot did not contain hexanucleotide SSRs. Single nucleotide polymorphisms (SNPs) of A/T, T/A and C/T were the largest number type, and the ratio of transition to transversion was from 0.37 to 0.55. Abelmoschus species showed relatively independent inverted-repeats (IR) boundary traits with different boundary genes compared with the other related Malvaceae species. The intergenic spacer regions had more polymorphic than protein-coding regions and intronic regions, and thirty mutational hotpots (≥200 bp) were identified in Abelmoschus, such as start-psbA, atpB-rbcL, petD-exon2-rpoA, clpP-intron1 and clpP-exon2.These mutational hotpots could be used as polymorphic markers to resolve taxonomic discrepancies and biogeographical origin in genus Abelmoschus. Moreover, phylogenetic analysis of 33 Malvaceae species indicated that they were well divided into six subfamilies, and genus Abelmoschus was a well-supported clade within genus Hibiscus.

Wild Paeonia ludlowii is considered as a traditional ornamental plant, but its flowers and seed oils are edible with important economic values, and the variation of nutrients, fatty acid composition in wild populations is scarcely known. Flowers and seeds of P. ludlowii were collected from two wild populations for evaluating the nutrients in flowers, composition of fatty acids in seed oils and the antioxidant activity. The flowers contained high composition of proteins, carbohydrates, amino acids, total flavonoids, phenolic compounds and essential minerals. Seed oil yield reached up to 21.95% using supercritical CO2 fluid extraction, and it contained 14 fatty acids (up to 93.35 g/100g seed oil), especially the unsaturated fatty acids (oleic acid, linoleic acid and α-linolenic acid) was up to 88.69% with low ω6/ω3 ratios of 0.58. The antioxidant capacity can be arranged in the order of trolox > flower extracts > seed oil according to the DPPH and ABTS free radical assay. Contents of nutrient in flowers and fatty acids in seed oils were significantly different between two wild populations due to the impact of different growing environments. These results indicate that flowers and seed oils of P. ludlowii are potential food resources in human diets.