Search Results (27)

To better understand the mitochondrial genome evolution within the genus Pedicularis, we investigated two representative species, Pedicularis kansuensis and Pedicularis chinensis. We sequenced and assembled the mitochondrial genomes of two Pedicularis species, P. kansuensis and P. chinensis, using Nanopore technology. Both genomes showed irregular morphological characteristics, with P. chinensis measuring 225,612 bp and P. kansuensis 273,598 bp, and GC (guanine and cytosine) contents of 44.42% and 44.29%, respectively. Each genome encodes 36 unique protein-coding genes, 3 rRNA genes, and varying numbers of tRNA genes (P. chinensis: 20; P. kansuensis: 19). Codon usage analysis revealed distinct preferences, while repeat sequence analysis identified significant differences in SSRs, tandem repeats, and dispersed repeats between the two genomes. Structural analyses highlighted genome recombination facilitated by repeat sequences. Phylogenetic analysis confirmed the placement of Pedicularis within Orobanchaceae, clustering P. kansuensis and P. chinensis with Castilleja paramensis and other genera in the family, thus resolving longstanding taxonomic uncertainties regarding their relationship with Scrophulariaceae. RNA editing events were predominantly C-to-U, ccmB and nad4 exhibiting the highest editing frequencies. Synteny analysis revealed frequent rearrangements, underscoring the dynamic evolution of Pedicularis mitochondrial genomes. These findings provide valuable insights into the structure, function, and evolution of mitochondrial genomes in parasitic plants. Full article

Host selectivity or preference plays a critical role in enabling parasitic plants to identify suitable hosts and influence plant community dynamics. Phosphorus (P) is known to affect the growth of root hemiparasitic plants and their interaction with single host species, but its role in shaping host selectivity across multiple hosts is unclear. In a pot experiment, we used a grass–legume co-culture design and evaluated whether the root hemiparasitic plant Pedicularis kansuensis exhibits selective parasitism on legumes (Medicago sativa) versus grasses (Elymus nutans) and assessed the impact of soil P availability on this preference. The results showed that P. kansuensis inhibited the growth of both host species, but the magnitude of suppression varied with P availability. Under low P conditions, P. kansuensis preferentially parasitized the tender M. sativa, causing a greater biomass reduction in the legume. In contrast, at high P levels, P. kansuensis decreased its foraging on legumes, shifting its parasitism towards the dominant E. nutans, which potentially led to stronger suppression of grass growth. Our findings demonstrate that soil P availability modulates host selectivity in P. kansuensis, emphasizing the influence of soil nutrient conditions on parasite–host dynamics. This research provides insights into managing the impacts of parasitic plants on plant community structure through nutrient interventions. Full article

Pedicularis hallaisanensis is a strictly biennial, hemiparasitic herb endemic to Republic of Korea and listed as an endangered species. Its populations are limited to high-altitude habitats, with recent surveys confirming survival only in Gayasan. This study aimed to assess the population size and ecological traits of P. hallaisanensis to inform conservation strategies. We established 23 quadrats at 1400–1410 m above sea level and collected microhabitat data (air temperature, soil moisture, electroconductivity, vegetation cover, and species richness) from 2022 to 2024. Flora composition and pollinator species were surveyed, with bumblebees (Bombus ignitus, B. hypocrita sapporoensis) identified as the most frequent pollinators. General linear mixed models and Pearson’s correlation analysis showed a strong positive relationship between species richness and population size and between vegetation cover and stem height. The study area’s average temperature was 6.3 °C below Republic of Korea’s national average, suggesting that climate change could disrupt the microclimatic conditions necessary for this species’ survival. The findings highlight the importance of maintaining plant diversity and controlling invasive woody species to sustain P. hallaisanensis populations. Targeted conservation measures, including habitat management and ex situ propagation, are recommended to safeguard this vulnerable species. Full article

Grassland degradation driven by overgrazing, invasive species, and climate change profoundly affects the dynamics and stability of soil organic carbon (SOC), yet the molecular mechanisms underlying these changes remain unclear. This study investigated the molecular composition and origins of SOC across different degradation stages—native grassland (NG), weed-dominated grassland (WG), and invasive grassland (IG) dominated by Pedicularis kansuensis—in the Bayinbuluke alpine region of China. Soil samples from three depth intervals (0–10 cm, 10–20 cm, and 20–30 cm) were analyzed using gas chromatography-mass spectrometry (GC-MS) to quantify biomarkers, including free lipids, ester-bound lipids, lignin phenols, and amino sugars. Principal component analysis (PCA) was applied to assess the overall variation in SOC composition. Compared to NG, plant-derived long-chain lipids and lignin phenols in WG and IG surface soils increased by 44–90% and 68–76% (p < 0.05), respectively, while cutin content increased by 96% and 150%. However, suberin content in IG decreased by 58% across all layers (p < 0.05). Microbial-derived carbon (MRC), including bacterial and fungal residues, increased significantly in the surface layer of degraded soils (IG > WG > NG), with MRC contributions to SOC also rising markedly in the subsurface layers (10–30 cm). PCA revealed a distinct separation of SOC components along the PC1 axis, highlighting the substantial impact of degradation on SOC composition and sources. These findings emphasize the role of vegetation shifts in SOC transformation and provide insights for grassland management and restoration strategies. Full article

Invasive plants (IPs) pose a significant threat to local ecosystems. Recent advances in remote sensing (RS) and deep learning (DL) significantly improved the accuracy of IP detection. However, mainstream DL methods often require large, high-quality labeled data, leading to resource inefficiencies. In this study, a deep learning framework called adversarial positive-unlabeled learning (APUL) was proposed to achieve high-precision IP detection using a limited number of target plant samples. APUL employs a dual-branch discriminator to constrain the class prior-free classifier, effectively harnessing information from positive-unlabeled data through the adversarial process and enhancing the accuracy of IP detection. The framework was tested on very high-resolution Jilin-1 and Sentinel-2 imagery of Bayinbuluke grasslands in Xinjiang, where the invasion of Pedicularis kansuensis has caused serious ecological and livestock damage. Results indicate that the adversarial structure can significantly improve the performance of positive-unlabeled learning (PUL) methods, and the class prior-free approach outperforms traditional PUL methods in IP detection. APUL achieved an overall accuracy of 92.2% and an F1-score of 0.80, revealing that Pedicularis kansuensis has invaded 4.43% of the local plant population in the Bayinbuluke grasslands, underscoring the urgent need for timely control measures. Full article

To target the lack of suitable grass species in the ecological restoration process of the Muli mining area, nine ecological grass species of Gramineae, Gentianaceae, Scrophulariaceae, and Ranunculaceae were selected as experimental materials to simulate the external alkaline environment for a seed germination test, which could be used to explore the response of seed germination to the environment. At the same time, Poa pratensis L. ‘Qinghai’, Deschampsia cespitosa, Koeleria cristata, and Elymus tangutorum were used as test materials to carry out a variety of comparison and screening tests of suitable seeding rates. The effects of the seeding rate on plant coverage, biomass, forage nutrients, and soil properties were analyzed by a variety of comparison and seeding rate tests. The results showed the following: (1) The relative germination rate of Koeleria cristata, Elymus tangutorum, Deschampsia cespitosa, and Poa pratensis L. ‘Qinghai’ was more than 70%, and the coverage in the returning green period was more than 60%, which was significantly higher than that of other treatments (p < 0.05) and can better adapt to the environment of the Muli mining area compared to other grass species. Meanwhile, the adaptability of Pedicularis kansuensis, Gentiana macrophylla, and Aconitum pendulum was weak. (2) It was found that when the seeding rate was 9 g·m⁻², the biomass of Poa pratensis L. ‘Qinghai’, Deschampsia cespitos, and Koeleria cristata was the highest, which was 296.45 g·m⁻², 224.32 g·m⁻², and 236.35 g·m⁻², which was significantly higher than that of other treatments (p < 0.05); the aboveground biomass was 356.24 g·m⁻² when the seeding rate of Elymus tangutorum was 18 g·m⁻², which was significantly higher than that of other treatments (p < 0.05). The membership function showed that the comprehensive evaluation value was 0.701, 0.576, 0.610, and 0.673 when the seeding rate of Poa pratensis L. ‘Qinghai’, Deschampsia cespitos, and Koeleria cristata was 9 g·m⁻² and the seeding rate of Elymus tangutorum was 18 g·m⁻². To sum up, it is recommended that the four ecological grass species of Poa pratensis L. ‘Qinghai’, Deschampsia cespitosa, Koeleria cristata, and Elymus tangutorum can be used as the main grass species for ecological restoration in high-altitude and alpine areas such as the Muli mining area, which is affected by an alpine climate and fragile habitats. The optimum sowing rate of Poa pratensis L. ‘Qinghai’, Deschampsia cespitosa, and Koeleria cristata is 9 g·m⁻², and that of Elymus tangutorum is 18 g·m⁻². This cultivation method can effectively promote plant growth and development, improve the physicochemical properties of soil, and is conducive to improving the stability and sustainability of artificial grassland in alpine mining areas. Full article

Pedicularis hallaisanensis Hurusawa, native to Mt. Halla and Gaya, is an endangered endemic species. To support conservation efforts, this study investigated its germination characteristics and kind of seed dormancy. The seeds of P. hallaisanensis had fully developed linear embryos at dispersal, with no additional embryo growth observed. Water imbibition was observed prior to germination. The seeds were water-permeable. The seeds did not germinate at four temperature treatments (4 °C/1 °C, 15 °C/6 °C, 20 °C/10 °C, and 25 °C/15 °C). However, cold stratification and gibberellic acid treatments broke seed dormancy. Total germination was 15%, 15%, and 45% at 12, 16, and 20 weeks of cold stratification, respectively. Total germination at 25 °C /15 °C for GA treatments were 0%, 25%, 25%, and 80% at 500, 1000, 1500, and 2000 mg/L, respectively. This study showed that the seeds of P. hallaisanensis have intermediate physiological dormancy, requiring 20 weeks of cold stratification or more than 2000 mg/L GA concentration to maximize total germination. These results are useful for understanding ecophysiological mechanisms related to the species’ habitat and for mass propagation to conserve this endangered species. Full article

Deep eutectic solvents (DESs) are mixtures of organic compounds displaying excellent solvent properties while keeping an ecofriendly character. In this study, DESs have been applied to the extraction of phenylpropanoid glycosides from Pedicularis oederi Vahl, successively separated by means of counter-current chromatography. Firstly, the ultrasonic-assisted extraction conditions were optimized by response surface methodology, and the results showed phenylpropanoid glycosides could be well extracted under the optimized extraction conditions with deep eutectic solvents. Then, the sample was separated by counter-current chromatography using ethyl acetate/aqueous solution of choline chloride and glycerol (6:6, v/v) as the solvent system. In about 360 min, four phenylpropanoid glycosides, including 31.6 mg of echinacoside, 65.3 mg of Jionoside A1, 28.9 mg of Forsythoside B, 74.1 mg of verbascoside, and 21.2 mg of kaempferol-3-O-rutinoside were obtained from about 900 mg of the sample. It revealed deep eutectic solvents could be well employed as a green solvent for the extraction and counter-current separation of natural products. Full article

The rapid spread of invasive plants presents significant challenges for the management of grasslands. Uncrewed aerial vehicles (UAVs) offer a promising solution for fast and efficient monitoring, although the optimal methodologies require further refinement. The objective of this research was to establish a rapid, repeatable, and cost-effective computer-assisted method for extracting Pedicularis kansuensis (P. kansuensis), an invasive plant species. To achieve this goal, an investigation was conducted into how different backgrounds (swamp meadow, alpine steppe, land cover) impact the detection of plant invaders in the Bayanbuluk grassland in Xinjiang using Random Forest (RF), Support Vector Machine (SVM) and eXtreme Gradient Boosting (XGBoost) with three feature combinations: spectral band, vegetation index (VI), and spectral band + VI. The results indicate that all three feature combinations achieved an overall accuracy ranging from 0.77 to 0.95. Among the three models, XGBoost demonstrates the highest accuracy, followed by Random Forest (RF), while Support Vector Machine (SVM) exhibits the lowest accuracy. The most significant feature bands for the three field plots, as well as the invasive species and land cover, were concentrated at 750 nm, 550 nm, and 660 nm. It was found that the green band proved to be the most influential for improving invasive plant extraction while the red edge 750 nm band ranked highest for overall classification accuracy among these feature combinations. The results demonstrate that P. kansuensis is highly distinguishable from co-occurring native grass species, with accuracies ranging from 0.9 to 1, except for SVM with six spectral bands, indicating high spectral variability between its flowers and those of co-occurring native background species. Full article

The targeting of suitable mixed grass species and seeding rates of native grass seed in the process of ecological restoration in alpine mining areas is unclear. Four kinds of native grass seed (Poa pratensis cv. Qinghai, Poa crymophila cv. Qinghai, Puccinellia tenuiflora cv. Tongde and Pedicularis kansuensis) were selected as experimental materials to set up mixed sowing tests in the Muli mining area, which were analyzed for changes in plant coverage, biomass, forage nutrient composition, and soil physicochemical properties under different mixed grass species and seeding rates, aiming to provide a data reference and theoretical basis for the screening of suitable mixed grass species and seeding rates for artificial grassland planting in alpine mining areas. The results showed that the mixed grass species and seeding rate (HF) of Poa pratensis cv. Qinghai + Poa crymophila cv. Qinghai + Puccinellia tenuiflora cv. Tongde + Pedicularis kansuensis had the highest vegetation coverage (97.33%). At the same time, the aboveground biomass of HF was the largest (356.27 g·m⁻²). The soil organic matter, total nitrogen, total phosphorus, and total potassium of HF increased by 37.05%, 28.11%, 34.68%, and 10.14%, respectively, compared with CK, and the difference was significant (p < 0.05). Principal component analysis was carried out on 23 indexes of vegetation and soil. It was found that nine indexes, including coverage, aboveground biomass, belowground biomass, soluble sugar, and soil organic matter content, were the key indexes of evaluation. By sorting the membership functions of the above indicators, it was found that among the 12 mixed grass species and seeding rates, the comprehensive evaluation value of HF was the highest (0.848). In summary, it is recommended that the mixed grass species and seeding rate of Poa pratensis cv Qinghai + Poa crymophila cv. Qinghai + Puccinellia tenuiflora cv. Tongde + Pedicularis kansuensis be adopted for ecological restoration in alpine mining areas; this mixed grass species and seeding rate can effectively promote plant growth and development and improve the physicochemical properties of the soil, which can improve the stability and sustainability of the artificial grassland in the alpine mining area. Full article

The Qinling Mountains in East Asia serve as the geographical boundary between the north and south of China and are also indicative of climatic differences, resulting in rich ecological and species diversity. However, few studies have focused on the responses of plants to geological and climatic changes in the Qinling Mountains and adjacent regions. Therefore, we investigated the evolutionary origins and phylogenetic relationships of three Pedicularis species in there to provide molecular evidence for the origin and evolution of plant species. Ecological niche modeling was used to predict the geographic distributions of three Pedicularis species during the last interglacial period, the last glacial maximum period, and current and future periods, respectively. Furthermore, the distribution patterns of climate fluctuations and the niche dynamics framework were used to assess the equivalence or difference of niches among three Pedicularis species. The results revealed that the divergence of three Pedicularis species took place in the Miocene and Holocene periods, which was significantly associated with the large-scale uplifts of the Qinling Mountains and adjacent regions. In addition, the geographic distributions of three Pedicularis species have undergone a northward migration from the past to the future. The most important environmental variables affecting the geographic distributions of species were the mean diurnal range and annual mean temperature range. The niche divergence analysis suggested that the three Pedicularis species have similar ecological niches. Among them, P. giraldiana showed the highest niche breadth, covering nearly all of the climatic niche spaces of P. dissecta and P. bicolor. In summary, this study provides novel insights into the divergence and origins of three Pedicularis species and their responses to climate and geological changes in the Qinling Mountains and adjacent regions. The findings have also provided new perspectives for the conservation and management of Pedicularis species. Full article

Root hemiparasites infiltrate the vascular tissue of host roots to acquire water and nutrients, which often reduces host growth. Hemiparasites are postulated to be keystone species in grassland communities if they suppress dominant species and increase plant community biodiversity, and ecosystem engineers if they increase nutrient accessibility for surrounding species. We examined keystone effects by evaluating species richness and evenness in 1 m² plots in a recent prairie restoration where Castilleja sessiliflora was naturally present or absent, and in a longer-established prairie restoration with or without Pedicularis canadensis. We examined ecosystem engineer effects by determining nitrate and phosphate concentrations under, 25 cm from, and 50 cm from hemiparasites, and in the center of hemiparasite-free plots. On the C. sessiliflora site, plots with the hemiparasites had higher species richness due to more forbs and higher floristic quality, consistent with the keystone species hypothesis. Soil phosphate levels were also greater in plots with C. sessiliflora present, consistent with the hypothesis of ecosystem engineering by this hemiparasite. In contrast, plots with/without P. canadensis showed no associations of any community metrics with the hemiparasite, and no correspondence between the presence of hemiparasites and soil nutrients. Although hemiparasites can increase grassland community heterogeneity, the effect is not universal, and the direction and strength of effects likely depends on local conditions. Full article

Rehmannia chingii is an important medicinal plant with immense value in scientific research. However, its mitochondrial genome (mitogenome) has not yet been characterized. Herein, based on whole-genome Illumina short reads and PacBio HiFi reads, we obtained the complete mitogenome of R. chingii through a de novo assembly strategy. We carried out comparative genomic analyses and found that, in comparison with the plastid genome (plastome) showing a high degree of structural conservation, the R. chingii mitogenome structure is relatively complex, showing an intricate ring structure with 16 connections, owing to five repetitive sequences. The R. chingii mitogenome was 783,161 bp with a GC content of 44.8% and contained 77 genes, comprising 47 protein-coding genes (CDS), 27 tRNA genes, and 3 rRNA genes. We counted 579 RNA editing events in 47 CDS and 12,828 codons in all CDSs of the R. chingii mitogenome. Furthermore, 24 unique sequence transfer fragments were found between the mitogenome and plastome, comprising 8 mitogenome CDS genes and 16 plastome CDS genes, corresponding to 2.39% of the R. chingii mitogenome. Mitogenomes had shorter but more collinear regions, evidenced by a comparison of the organelles of non-parasitic R. chingii, hemiparasitic Pedicularis chinensis, and holoparasitic Aeginetia indica in the Orobanchaceae family. Moreover, from non-parasitic to holoparasitic species, the genome size in the mitogenomes of Orobanchaceae species did not decrease gradually. Instead, the smallest mitogenome was found in the hemiparasitic species P. chinensis, with a size of 225,612 bp. The findings fill the gap in the mitogenome research of the medicinal plant R. chingii, promote the progress of the organelle genome research of the Orobanchaceae family, and provide clues for molecular breeding. Full article

Epichloë endophytes not only affect the growth and resistance of their host plants but also confer nutrient benefits to parasitized hosts. In this study, we used Pedicularis kansuensis to parasitize Stipa purpurea, both with and without endophytic fungi, and to establish a parasitic system. In this study, endophytic fungal infection was found to increase the dry weight of the leaf, stem, and leaf sheath, as well as the plant height, root length, tiller number, aboveground biomass, and underground biomass of S. purpurea under root hemiparasitic stress. Meanwhile, the ¹³C allocation of the leaf sheaths and roots of S. purpurea increased as the density of P. kansuensis increased, while the ¹³C allocation of the leaf sheaths and roots of E+ S. purpurea was lower than that of E− S. purpurea. The ¹³C allocation of the stem, leaf sheath, and root of E+ S. purpurea was higher than that of its E− counterpart. Furthermore, the content of photosynthetic ¹³C and the ¹³C partition rate of the stems, leaves, roots, and entire plant of S. purpurea and P. kansuensis transferred from S. purpurea increased as the density of P. kansuensis increased. These results will generate new insights into the potential role of symbiotic microorganisms in regulating the interaction between root hemiparasites and their hosts. Full article

The accurate identification and monitoring of invasive plants are of great significance to sustainable ecological development. The invasive Pedicularis poses a severe threat to native biodiversity, ecological security, socioeconomic development, and human health in the Bayinbuluke Grassland, China. It is imperative and useful to obtain a precise distribution map of Pedicularis for controlling its spread. This study used the positive and unlabeled learning (PUL) method to extract Pedicularis from the Bayinbuluke Grassland based on multi-period Sentinel-2 and PlanetScope remote sensing images. A change rate model for a single land cover type and a dynamic transfer matrix were constructed under GIS to reflect the spatiotemporal distribution of Pedicularis. The results reveal that (1) the PUL method accurately identifies Pedicularis in satellite images, achieving F1-scores above 0.70 and up to 0.94 across all three datasets: PlanetScope data (seven features), Sentinel-2 data (seven features), and Sentinel-2 data (thirteen features). (2) When comparing the three datasets, the number of features is more important than the spatial resolution in terms of use in the PUL method of Pedicularis extraction. Nevertheless, when compared with PlanetScope data, Sentinel-2 data demonstrated a higher level of accuracy in predicting the distribution of Pedicularis. (3) During the 2019–2021 growing season, the distribution area of Pedicularis decreased, and the distribution was mainly concentrated in the northeast and southeast of Bayinbuluke Swan Lake. The acquired spatiotemporal pattern of invasive Pedicularis could potentially be used to aid in controlling Pedicularis spread or elimination, and the methods proposed in this study could be adopted by the government as a low-cost strategy to identify priority areas in which to concentrate efforts to control and continue monitoring Pedicularis invasion. Full article