The diverse members of the genus Daphne are prized for their fragrant flowers. Despite being promising ornamental plants in many countries, genetic information of Daphne is scarce. In this study, the plastomes of four species and one variety of Daphne were sequenced and analyzed. The plastomes were typical and contained a pair of inverted repeat (IR) regions that separated the large single-copy (LSC) region from the small single-copy (SSC) region. With a length ranging from 132,869 bp (D. genkwa) to 174,773 bp (D. championii), 106 to 141 genes were predicted. Comparative plastome analysis of the newly sequenced plastomes with four publicly available Daphne plastomes identified an expansion of the IRs, sequence variations, and mutational hotspots. Phylogenetic analyses indicated that the genus Daphne in its current circumscription is polyphyletic. Daphne genkwa was nested within the genus Wikstroemia, while D. championii was well resolved as sister to Edgeworthia. These findings concurred with results from our study that used nuclear ribosomal internal transcribed spacer sequence data. The conflicts on the molecular placement of D. championii and D. genkwa and the present taxonomic classification in Daphne suggest that a new intergeneric classification system of Daphneae warrants consideration.

Bougainvillea is popular in ornamental horticulture for its colorful bracts and excellent adaptability, but the complex genetic relationship among this genus is fuzzy due to limited genomic data. To reveal more genomic resources of Bougainvillea, we sequenced and assembled the complete chloroplast (cp) genome sequences of Bougainvillea spectabilis ‘Splendens’. The cp genome size was 154,869 bp in length, containing 86 protein-coding genes, 38 tRNAs, and eight rRNAs. Cp genome comparison across 12 Bougainvillea species (B. spectabilis, B. glabra, B. peruviana, B. arborea, B. praecox, B. stipitata, B. campanulata, B. berberidifolia, B. infesta, B. modesta, B. spinosa, and B. pachyphylla) revealed five mutational hotspots. Phylogenetic analysis suggested that B. spectabilis published previously and B. glabra clustered into one subclade as two distinct groups, sister to the subclade of B. spectabilis ‘Splendens’. We considered the phylogeny relationships between B. spectabilis and B. glabra to be controversial. Based on two hypervariable regions and three common plastid regions, we developed five molecular markers for species identification in Bougainvillea and applied them to classify 53 ornamental Bougainvillea cultivars. This study provides a valuable genetic resource for Bougainvillea breeding and offers effective molecular markers to distinguish the representative ornamental species of Bougainvillea.

The agarwood-producing genera, Aquilaria and Gyrinops, have been treated as sister genera in Thymelaeaceae (Aquilarieae, Malvales). However, there are differing opinions about their taxonomic positions. Using new evidence from complete plastid genome (plastome) sequences of 12 Aquilaria spp. and seven Gyrinops spp., corresponding to more than half the total number of species recognized in each genus, we reconstructed a phylogenetic tree of Aquilarieae. Members of both genera shared similar sequence variations at the plastome level. The phylogenetic relationships of the two genera were completely resolved using the complete plastome sequences. Gyrinops was paraphyletic to Aquilaria, i.e. Aquilaria nested in Gyrinops. Overlapping clustering patterns were observed from topology-clustering analysis using the complete plastome and the protein-coding gene sequences, which further reinforced the paraphyletic link. The maximum-likelihood-based RelTime analysis suggested that Aquilarieae and Daphneae diverged c. 44 Mya during the Eocene, followed by a rapid divergence event in Aquilarieae, with the split between G. vidalii and G. walla c. 1.24 Mya during the Pleistocene. Our new phylogenetic estimation demonstrates the relationship between the two genera, which will aid in future taxonomic revisions involving members of Aquilarieae.

The chloroplast genomes of Dioscorea brevipetiolata, D. depauperata, D. glabra, and D. pyrifolia are 153,370–153,503 bp in size. A total of 113 genes were predicted, including 79 protein-coding sequences (CDS), 30 tRNA, and four rRNA genes. The overall GC content for all four species was 37%. Only mono-, di-, and trinucleotides were present in the genome. Genes adjacent to the junction borders were similar in all species analyzed. Eight distinct indel variations were detected in the chloroplast genome alignment of 24 Dioscorea species. At a cut-off point of Pi = 0.03, a sliding window analysis based on 25 chloroplast genome sequences of Dioscorea species revealed three highly variable regions, which included three CDS (trnC, ycf1, and rpl32), as well as an intergenic spacer region, ndhF-rpl32. A phylogenetic tree based on the complete chloroplast genome sequence displayed an almost fully resolved relationship in Dioscorea. However, D. brevipetiolata, D. depauperata, and D. glabra were clustered together with D. alata, while D. pyrifolia was closely related to D. aspersa. As Dioscorea is a diverse genus, genome data generated in this study may contribute to a better understanding of the genetic identity of these species, which would be useful for future taxonomic work of Dioscorea.

The complete chloroplast genomes of three species ofEdgeworthianamely,Edgeworthia albiflora,Edgeworthia chrysantha, andEdgeworthia gardneri(Thymelaeaceae), are reported and characterized. The chloroplast genomes displayed a typical quadripartite structure with conserved genome arrangement and specific divergence. The genomes ranged in length from 172,708 to 173,621 bp and displayed similar GC content of 36.5–36.7%. A total of 138–139 genes were predicted, including 92–93 protein-coding, 38 tRNAs and eight rRNAs genes. Variation in the number of short simple repeats and inverted region boundaries of the three cp genomes were observed. A mutational hotspot was detected along the nucleotide sequence from thendhF to thetrnL-UAG genes. The chloroplast genome-based and internal transcribed spacer (ITS)-based phylogenetic analyses using maximum-likelihood (ML) and Bayesian inference (BI) revealed thatE. albifloradiverged beforeE. chrysanthaandE. gardneriand placed theEdgeworthiaclade at the base of the Eurasian Daphne group with strong bootstrap support. With an effective taxonomic treatment of the species ofEdgeworthia, further molecular analyses of their intra- and interspecific genetic variation are inclined to support the treatment ofE. albifloraandE. gardnerias two natural groups. The genetic information obtained from this study will provide valuable genomic resources for the identification of additional species and for deducing the phylogenetic evolution ofEdgeworthia.

Enzymatic browning is a common limiting factor in the fruit industry because it causes significant losses through fresh product deterioration, affecting taste, flavor, and nutrition. Artocarpus odoratissimus, locally known as terap, is an exotic indigenous fruit to Borneo. This fruit remains underutilized due to its perishability, short shelf-life, and peel browning. Currently, no information has apparently been published on the browning mechanisms of A. odoratissimus. Thus, the present study aims to evaluate the degree of browning and enzymatic activities in relation to the phytochemical contents in A. odoratissimus during postharvest ripening. The experimental design consists of packaging (without packaging and with packaging) and storage temperatures (ambient at 25 °C, and cold storage at 10 °C), which were arranged in a randomized complete block design. Findings showed significantly higher weight loss in fruit stored at 25 °C on days 4 (T1) at 12.20 ± 0.19% and 8 (T5) at 11.09 ± 0.24%. The degree of browning was higher in the fruits stored with packaging at 25 °C, collected on day 4 at 0.48 ± 0.01 and day 8 at 0.51 ± 0.02, and consequently, the phenylalanine ammonia-lyase (671.00 ± 5.25 UE g⁻¹ min⁻¹) and polyphenol oxidase (670.00 ± 2.56 UE g⁻¹ min⁻¹) enzymatic activities were also higher. The lower enzymatic activities were recorded in the fruit stored at 10 °C without packaging, resulting in the least degree of browning. The fruit with the lowest enzymatic activities was stored at 10 °C without packaging, resulting in the least amount of browning. This trend is supported by lower total phenolic content (TPC) and is explained by a strong positive correlation between TPC and PAL (r = 0.927). Low-temperature storage was effective in reducing the effect of browning and deterioration on A. odoratissimus for up to 16 days. The results not only provided insights into the peel browning in A. odoratissimus but also guidance on controlling postharvest fruit browning.