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Adonis amurensis Regel et Radde is an early spring plant in northeastern China that has great ornamental value because it blooms before other plants have sprouted. It has not been used to its full potential due to environmental restrictions on its growth. It will be extremely important for its application to comprehend the possible habitat of A. amurensis and the critical environmental factors controlling its distribution under current and future climatic scenarios. In this work, two climate change scenarios of 2041–2060 and 2081–2100 were utilized to predict the suitable habitat of A. amurensis. The results showed that the suitable habitat was mainly distributed along the Changbai Mountains, with a total area of 303,090 km2, and the potential and high‐potential habitat area were 141,218 and 161,872 km2, respectively. In the future climate scenarios, the suitable habitat of A. amurensis was still distributed along the Changbai Mountains, but the area was reduced. In ssp126 and ssp585 scenarios of 2041–2060 and 2081–2100, the area was reduced by 7.13% and 22.34% and 18.66% and 8.09%, respectively. The reduced suitable habitat was mainly located in central Heilongjiang (southeastern Xiao Xing'an Ling), central Jilin, and northeastern Liaoning. The suitable habitat was significantly influenced by precipitation, mainly affected by annual precipitation, followed by precipitation seasonality, soil surface pH, and slope. The results of this study can serve as empirical support for the artificial cultivation, ecological restoration, and long‐term use of A. amurensis. [ABSTRACT FROM AUTHOR]

Aim: Dispersal and subsequent adaptation to local environmental and climatic conditions play major roles in the evolution and current‐day distribution of plants and animals, but their relative importance is not always easy to disentangle. The aim of this study was to provide a comprehensive phylogenetic analysis of the terrestrial orchid genus Cypripedium to better understand the role of niche evolution and historical dispersal events in driving the radiation of the genus in North America and Eurasia. Location: Northern Hemisphere. Taxon: Cypripedium (Orchidaceae). Methods: We used a relaxed molecular clock analysis to infer phylogenetic relationships among 45 Cypripedium species and to estimate divergence times. Niche modelling was used to assess the potential distribution of each species in both continents, whereas ancestral area reconstructions using BioGeoBEARS were used to estimate changes in historical biogeography. Subsequently, the ancestral state of niche conditions was assessed for each species using maximum likelihood methods and we tested for phylogenetic signal in the evolution of niche conditions using Blomberg's K and Pagel's λ. A mantel test was used to test for a correlation between phylogenetic distances and niche overlap in Cypripedium. Results: We found that Cypripedium originated in Central America and underwent multiple dispersal events between North America and Eurasia after long‐distance seed dispersal or dispersal via the Bering land bridge. The mountainous area of Southwest China provided refuge areas for Cypripedium orchids during episodes of increased glaciation. Our results further showed that Cypripedium has gradually increased its tolerance to seasonal temperature changes, providing evidence for significant niche evolution through time. No significant correlation between current niches and phylogenetic relatedness was observed. Main conclusions: Our study provides clear evidence that repeated dispersal and adaptation to increased cooling after the Eocene−Oligocene Transition has contributed to the radiation of Cypripedium in the Northern Hemisphere. [ABSTRACT FROM AUTHOR]

Human pressure on the environment and climate change are two important factors contributing to species decline and overall loss of biodiversity. Orchids may be particularly vulnerable to human-induced losses of habitat and the pervasive impact of global climate change. In this study, we simulated the extent of the suitable habitat of three species of the terrestrial orchid genus Cypripedium in northeast China and assessed the impact of human pressure and climate change on the future distribution of these species. Cypripedium represents a genus of long-lived terrestrial orchids that contains several species with great ornamental value. Severe habitat destruction and overcollection have led to major population declines in recent decades. Our results showed that at present the most suitable habitats of the three species can be found in Da Xing'an Ling, Xiao Xing'an Ling and in the Changbai Mountains. Human activity was predicted to have the largest impact on species distributions in the Changbai Mountains. In addition, climate change was predicted to lead to a shift in distribution towards higher elevations and to an increased fragmentation of suitable habitats of the three investigated Cypripedium species in the study area. These results will be valuable for decision makers to identify areas that are likely to maintain viable Cypripedium populations in the future and to develop conservation strategies to protect the remaining populations of these enigmatic orchid species. [ABSTRACT FROM AUTHOR]

• A. amurensis has higher drought resistance than A. pseudoamurensis. • Activities of enzymes were closely related to the secondary metabolites. • Enzymes, osmo-regulators and secondary metabolites are key roles to resist drought. Adonis amurensis Regel et Radde and Adonis pseudoamurensis W. T. Wang are important plant species of Adonis due to their medical and ornamental benefits, and they are widely distributed in Northeast China. The drought resistance mechanism of two Adonis species were measured under natural drought exposure. The seedings of A. amurensis and A. pseudoamurensis were planted in plastic pots which have been filled with soil mixture, and subjected to drought stress by withholding water for 30 days. The changes in growth, physiology and secondary metabolites were monitored. The results showed that the two Adonis species showed stronger resistance in the early stages of drought, mainly expressed as the increase of osmotic substances such as proline (Pro) and sugar (SS) content, enzyme activity (superoxide dismutase (SOD) and ascorbate peroxidase (APX)), secondary metabolites such as flavonoids (FC), total phenols (TPC) and hormone concentrations (abscisic acid (ABA)) and the decrease of relative leaf water content (RLWC). The higher RLWC, FC, TPC, Pro, soluble protein (SP) and ABA content and lower H 2 O 2 content indicates the stronger non-enzymatic antioxidant system and drought resistance of A. amurensis. However, the synthesis of SP and SS, GA, activities of CAT and POD of two plant species were inhibited in the late stages of drought stress. In general, this two Adonis species response to drought stress rely primarily on enhancing osmotic regulators, antioxidant enzymes and secondary metabolite levels. [ABSTRACT FROM AUTHOR]

The growth and quality of medicinal plants depend heavily on environmental variables. The quality of Rubia cordifolia , an important medicinal plant, is determined by the two main secondary metabolites of the root, purpurin and mollugin. However, their relationship with environmental factors has not been studied. In this study, the purpurin and mollugin contents of R. cordifolia roots from different sampling sites in China were measured using ultra-high-performance liquid chromatography, and the correlations between the two secondary metabolites and environmental variables were analyzed. The results showed that there were significant differences in the contents of purpurin and mollugin in the roots of R. cordifolia at different sampling points. The content of purpurin ranged from 0.00 to 3.03 mg g -1 , while the content of mollugin ranged from 0.03 to 10.09 mg g -1 . The quality of R. cordifolia in Shanxi, Shaanxi and Henan border areas and southeastern Liaoning was higher. Liaoning is expected to become a R. cordifolia planting area in Northeast China. Correlation and regression analysis revealed that the two secondary metabolites were affected by different environmental factors, the two secondary metabolites contents were positively correlated with longitude and latitude, and negatively correlated with soil nutrients. In addition, higher temperature and shorter sunshine duration facilitated the synthesis of purpurin. Annual precipitation might be the main factor limiting the quality of R. cordifolia because it had opposite effects on the synthesis of two major secondary metabolites. Therefore, this study is of great significance for the selection of R. cordifolia planting areas and the improvement of field planting quality., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wang, Liu, Yu, Zhang, Huang, He and Chen.)