Wild orchids, valued for their beauty and economic importance, are facing the challenges of distribution contraction and range shifts from climate change. The rare Cymbidium cyperifolium (class II in the List of National Key Protected Wild Plants in China, Vulnerable on the China Biodiversity Red List) remains understudied regarding its responses to climate variability. Utilizing an enhanced MaxEnt model, we predicted suitable habitats under diverse climate scenarios, revealing a potential distribution of 52.37 × 10⁴ km², concentrated in eastern Yunnan, western Guangxi, the Guizhou border, and southern Hainan. Cymbidium cyperifolium is sensitive to climate change, and temperature annual range (Bio 7) contributes a significant 77.42% of the distribution probability (i.e., habitat suitability), highlighting temperature’s pivotal influence on its distribution. Although the overall potential distribution area and low-suitability regions in China are predicted to decrease, medium and high-suitability areas are expected to expand. The center of mass of the high-altitude habitat is concentrated in southeastern Yunnan Province, migrating just slightly, yet tending westward and northeastward. Based on these findings, we recommend the expansion of existing protected areas or the establishment of new ones for C. cyperifolium, particularly in eastern Yunnan and western Guangxi. Additionally, our research can serve as a reference for the ex situ conservation of C. cyperifolium and other orchids with similar ecological habits, underscoring the broader implications in biodiversity preservation efforts.

The genus Cymbidium, with its intricate floral elements, pronounced endemicity, and patchy distribution, evolves a rich diversity of morphological forms and a wide variety of species while causing an indistinctness in the classification of its species. To elucidate the phylogenetic relationships among Cymbidium species and enhance their taxonomic classification by DNA barcoding, this study conducted amplification and sequence results of nuclear (ITS) and chloroplast genes (matK, rbcL, trnL-F, psbA-trnH) with phenotypic genetic diversity analysis, genetic distance analysis, and phylogenetic analysis from 48 samples of Cymbidium species. The comparison of genetic distance variations showed that psbA-trnH, ITS + psbA-trnH, and ITS + matK + psbA-trnH exhibit minimal overlap and significant genetic variation within Cymbidium species. The phylogenetic analysis indicated that the combination, ITS + matK + psbA-trnH, has the highest identification rate. Notably, both the phylogenetic analysis and the genetic diversity analysis of phenotypic traits consistently indicated a clear divergence between epiphytic and terrestrial orchids, with epiphytic orchids forming a distinct clade. This provides reference evidence for studying the ecological adaptations and evolutionary differences between epiphytic and terrestrial orchids, as well as a scientific basis for the classification and identification, germplasm conservation, resource utilization, and phylogenetic evolution of orchids.

Bougainvillea has large and vibrant-colored bracts, which are widely used in landscape gardening. In order to study the changing pattern of pigmentation and the expression of genes related to pigment synthesis during different developmental periods of the bracts of B. × buttiana, we determined the color parameters of the bracts of B. × buttiana has by using colorimetric color cards and colorimeters, and quantitatively determined the contents of chlorophyll a, chlorophyll b, betacyanin, betaxanthin and flavonoids, and the expression of genes related to pigment synthesis was detected during the BR1 and BR3. The results showed that the bracts of B. × buttiana ‘Miss Manila’ can be classified into four distinct growth and developmental stages, namely Bract Primordial Stage (BR1), Bract Color Transition Stage (BR2), Bract Maturation Stage (BR3), and Bract Senescence Stage (BR4). The BR1 have lower color saturation, brightness, and redness, and with bract development, their color saturation, brightness, and redness gradually increased. In addition, chlorophyll content was highest at the BR1 (2.2 mg/g), and from the BR1, flavonoids and betalain content began to increase, and higher betacyanin content in all stages, with betacyanin being the highest at the BR3 at 4.94 mg/g. Correlation analysis of the color parameters with pigment content showed that chlorophyll a, betacyanin, and flavonoid contents were significantly correlated with the bract color changes. With bract development, the betalain metabolism pathway BgDODA gene was significantly up-regulated; the flavonoid metabolism pathway BgDFRA and BgF3H genes were significantly up-regulated, whereas the BgDTX, BgFLS, and BgCHIL genes were significantly down-regulated; and the chlorophyll metabolism pathway BgSGR gene was significantly up-regulated, whereas the BgPORA gene was down-regulated in expression. ProtParam-based analysis characterized the BgFLS-encoded protein as a stable, hydrophilic 2-oxoglutarate-dependent oxidoreductase lacking transmembrane domains and a signal peptide, and the BgCHIL-encoded protein as a stable, hydrophilic chalcone isomerase also lacking transmembrane domains and a signal peptide. In summary, betalain metabolism, flavonoid metabolism and chlorophyll metabolism jointly regulate the bract color change of B. × buttiana has, and it is possible that the genes of BgCHIL, BgFLS, BgSGR, and BgF3H are involved in the regulation of the bract color change of B. × buttiana.

Montane forests are commonly limited by phosphorus (P) scarcity, yet Rhododendron species persist via specialized P-acquisition strategies. However, the microbial processes governing P utilization among wild Rhododendron species remain unclear. We collected soil and root samples from three wild Rhododendron species—Rhododendron latoucheae Franch. (R. latoucheae), Rhododendron fortunei Lindl. (R. fortunei) and Rhododendron simsii Planch. (R. simsii)—in a montane forest and analyzed soil P fractions, acid phosphatase activity, and fungal community traits to investigate their relationships with P cycling. The results showed significant differences in P fraction contents between non-rhizosphere and rhizosphere soils among the three species. In R. fortunei, rhizospheric NaOH-Po decreased tenfold while H₂O-Pi increased by 9.13 mg/kg, indicating a shift toward labile P. In contrast, R. latoucheae and R. simsii showed increases in moderately labile P by 32.54% and 22.09%, respectively. R. latoucheae exhibited the lowest acid phosphatase activity in non-rhizosphere soil (4.810 ± 0.560 μmol/d/g), which increased significantly in the rhizosphere. Fungal community analysis revealed a significant enrichment of Podila in the rhizosphere of R. latoucheae (10.84%) and R. simsii (9.17%), while Penicillium (6.80%), Trichoderma (3.65%) and Mortierella (5.83%) were dominant in the R. fortunei rhizosphere. R. latoucheae mineralized organic P through acid phosphatase hydrolysis driven by nutrient scarcity. R. fortunei likely mobilizes inorganic P through ericoid mycorrhizal-associated secretion of organic acids and the activity of specialized phosphate-solubilizing fungi facilitated by high substrate availability. Soil nutrients (SOC, TN, $\mathrm{N}{\mathrm{O}}_3^{-}$-N) influenced fungal abundances and indirectly shaped soil P fractions, whereas fungal taxa abundance in the rhizosphere directly drove P turnover. Our results confirm that different wild Rhododendron species employ distinct P-acquisition strategies mediated by rhizosphere fungi and enzyme activities, and provide new insights into microbial-driven P cycling in montane forests.