Xiu Hu

Wild plants with high ornamental value, such as Hedychium species, offer untapped potential for enhancing urban biodiversity and sustainability. However, their integration into urban landscapes is hindered by a lack of cultivation protocols and climate uncertainty. This study addresses these challenges by identifying low-maintenance, climate-resilient Hedychium species suitable for near-nature urban landscaping-a strategy critical for reducing irrigation dependency and fostering ecological resilience in cities. In this paper, firstly, we developed an approach to evaluate the near-nature landscaping suitability of four Hedychium species representative of four ecologic types in China based on MaxEnt and GIS, and identified that Kunming is the most suitable metropolises for landscaping the most Hedychium species sustainably in China. Furthermore, potential suitable areas for these species were projected under two distinct climate change scenarios (SSP2-4.5 and SSP5-8.5). The results indicate divergent trends by the 2070s: under the SSP2-4.5 scenario, suitable habitats for H. coronarium, H. villosum, and H. coccineum are projected to expand, whereas H. sinoaureum faces significant habitat contraction. Conversely, under the SSP5-8.5 scenario, a shift occurs where the habitat for H. villosum contracts significantly, while H. sinoaureum achieves a slight expansion. Thirdly, Temperature Seasonality (Bio4) was identified as the main factor affecting the distribution of four species, which gives hints to how to landscaping Hedychium in less favorable areas. This methodology empowers urban planners to identify low-maintenance, climate-resilient species tailored to specific cities, advancing global efforts toward sustainable urban ecosystems.

Several phylogenetic studies have revealed that Murraya s. lat. is not monophyletic, suggesting that it should be split into two genera, namely Murraya s. str. and Bergera J.Koenig ex L. Here, the genus Bergera is comprehensively revised based on molecular and morphological data. The genus consists of 11 species in total, including all species previously placed in Murraya sect. Bergera and an additional species previously placed in Murraya sect. Murraya. Ten new combinations are proposed, namely Bergera alternifolia (Kurz) F.J.Mou comb. nov., B. crenulata (Turcz.) F.J.Mou comb. nov., B. euchrestifolia (Hayata) F.J.Mou comb. nov., B. glabra (Guillemin) F.J.Mou comb. nov., B. kwangsiensis (C.C.Huang) F.J.Mou comb. nov., B. macrophylla (C.C.Huang) F.J.Mou comb. nov., B. microphylla (Merr. & Chun) F.J.Mou comb. nov., B. siamensis (Craib) F.J.Mou comb. nov., B. stenocarpa (Drake) F.J.Mou comb. nov., and B. tetramera (C.C.Huang) F.J.Mou comb. nov. An identification key of the 11 species and morphological descriptions are provided, as well as illustrations of diagnostic characteristics. Phylogenetic relationships of the species in Bergera are discussed.

This study aimed to explore the anti-bacterial and anti-fungal activities of extracts from different parts of plants in the Zingiberaceae family. The inhibitory rate, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) of leaf and stem, and root and rhizome extracts from Alpinia katsumadai Hayata, Alpinia oxyphylla Miq × Alpinia henryi K. Schumann, Alpinia oblongifolia Hayata, Alpinia nigra (Gaertn.) Burtt, Amomum villosum Lour, Alpinia zerumbet (Pers.) Burtt. et Smith and Alpinia oxyphylla Miq were determined using the fungus cake method and double dilution method. The seven Zingiberaceae plants exhibited characteristic antibacterial activities against pathogenic bacteria and fungi. At a 1.5 mg mL−1, A. zerumbet root and rhizome extracts exhibited strong inhibitory activity against S. aureus and E. coli, with 83.23% and 79.62%, respectively. In addition, A. zerumbet leaf and stem extracts had an inhibitory rate of 90.85% against P. aeruginosa. At the same concentration, the leaf and stem, root and rhizome extracts of A. katsumadai had the best antibacterial effect against F. oxysporum, with inhibition rates of 84.46% and 84.73%, respectively. Moreover, A. katsumadai and A. zerumbet leaf and stem extracts had the most significant antibacterial effect against S. aureus, with a MIC of 0.063 mg mL−1 . Thus, both A. katsumadai and A. zerumbet extracts had significant antibacterial activity. In addition, by comparing the inhibitory effect of extracts from different parts, it was found that the inhibitory rate and average inhibitory rate of extracts from leaf and stem were higher than those from root and rhizome. The chemical constituents of A. katsumadai and A. zerumbet, determined by the high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), revealed that citric acid (CA), alpinetin, and pinocembrin (PNCB) were the functional constituents yielding the antibacterial activity. Overall, A. katsumadai and A. zerumbet have the potential to be developed as new plant fungicides and bactericides.

Hedychium coronarium J. Koenig is a multipurpose plant with significant economic value, but it has been overexploited and listed as a vulnerable, near threatened or endangered species. In vitro culture methods have been used for propagating disease-free propagules for its conservation and production. However, explant contamination has been a bottleneck in in vitro propagation due to the use of rhizomes as the explant source. Plants in the family Zingiberaceae have pseudostems that support inflorescences, while rhizomes are considered true stems. The present study, for the first time, reported that the pseudostem bears nodes and vegetative buds and could actually be true stems. The evaluation of different sources of explants showed that mature node explants derived from the stem were the most suitable ones for in vitro culture because of the lowest contamination and the highest bud break rates. Culture of mature node explants on MS medium supplemented with 13.32, 17.76, and 22.20 μM 6-benzylaminopurine (BA), each in combination with 9.08 μM thidiazurin (TDZ) and 0.05 μM α-naphthaleneacetic acid (NAA) induced the conversion of buds to micro-rhizomes in six weeks. More than 96% of the micro-rhizomes cultured on MS medium supplemented with 17.76 μM BA, 6.81 μM TDZ, and 2.46 μM indole-3-butyric acid (IBA) were converted to globular-shaped clumps with protocorm-like bodies (PLBs). Further culture of a piece of the clumps induced more than 15 adventitious shoots. Adventitious roots were produced at the base of adventitious shoots, and plantlets were readily transplanted to a substrate for acclimatization in a shaded greenhouse. The survival rate of the plants in the greenhouse was up to 90%. Plants grew vigorously, and there were no off-types from the regenerated 11,100 plants. Our study also, for the first time, shows that H. coronarium can be regenerated via PLBs, which may represent a new way of the in vitro propagation of H. coronarium. The established protocol could be used for the increased propagation of H. coronarium for conservation or commercial production.