Search Results (428)

Phoebe bournei is a precious timber species unique to China, possessing significant ornamental, ecological, and medicinal values. The polyembryonic phenomenon is widely observed in its seeds, but the underlying mechanisms driving its formation remain unclear. In this study, an integrated analysis was conducted for polyembryony formation in P. bournei seeds, including biochemical indicators, environmental factors, and transcriptional levels. Firstly, morphological observation of seeds from 13 plus trees showed no significant correlation between polyembryony rate and external environment or seed morphology. Subsequently, comparative transcriptomic analysis between monoembryonic and polyembryonic seeds identified 1957 differentially expressed genes (DEGs), which were significantly enriched in biological processes and pathways including photosystem II, tetrapyrrole binding, heme binding, and phenylpropanoid biosynthesis, indicating the probable effect of gene regulation in polyembryony formation. Furthermore, eight RWP transcription factors were identified, potentially involved in polyembryony. qRT-PCR analysis revealed that the expression levels of PbRWP2 and PbRWP5 were significantly upregulated in polyembryonic seeds, indicating they may be key regulatory genes during polyembryony formation in P. bournei seeds. This study preliminarily explored the transcriptomic characterization and potential molecular regulatory basis of polyembryony formation in P. bournei, laying a critical foundation for further deciphering the intricate mechanisms governing its polyembryonic development. Full article

Allium kazim-kosei sp. nov. (Amaryllidaceae, sect. Codonoprasum) is described as a new species from Central Anatolia, Türkiye. The new species is morphologically similar to A. pseudoflavum but differs in several diagnostic characters, including bulb structure, scape height, leaf morphology, spathe venation, inflorescence and pedicel dimensions, tepal shape, presence of interstaminal teeth, capsule shape, and seed size. SEM observations reveal distinct micromorphological differences in seed testa ornamentation and pollen exine structure between the two species. Molecular phylogenetic analyses based on nuclear ITS and chloroplast trnL intron sequences support the recognition of A. kazim-kosei as a distinct species. The Kimura 2-parameter (K2P) genetic distance between A. kazim-kosei and A. pseudoflavum (8.54% for ITS) is considerably higher than typical interspecific divergences within sect. Codonoprasum. In the Maximum Likelihood phylogenetic tree, the two species form well-separated sister branches with high bootstrap support. The species is known only from gypseous soils around Kavuncu village (Eskişehir province, Türkiye), with an estimated Area of Occupancy (AOO) of 8 km² and Extent of Occurrence (EOO) of 45 km². Based on IUCN criteria, A. kazim-kosei is assessed as Endangered (EN) [B1ab(iii) + B2ab(iii)]. This discovery increases the total number of Allium species in Türkiye to 239 and the number of sect. Codonoprasum taxa to 74. The molecular results are fully congruent with the macro- and micromorphological characters, providing robust multi-evidence support for the recognition of the new species. Full article

Alsophila spinulosa is a tree fern designated as a second-class nationally protected species in China and valued for its medicinal and ornamental properties. Its slow growth and susceptibility to environmental stresses pose challenges to its cultivation. Plant-growth-promoting rhizobacteria (PGPR) can enhance plant development by producing phytohormones, such as indole-3-acetic acid (IAA). In this study, 39 IAA-producing strains were isolated from the rhizosphere of A. spinulosa. Morphological and molecular analyses identified the highest IAA-producing strain, R74, as Burkholderia pyrrocinia. Its optimal inoculum age was determined to be 12–20 h, and its optimal culture conditions for IAA production were 24 h of incubation, 32 °C and pH 7.0. Whole-genome sequencing revealed that the genome of strain R74 is 8,347,169 bp in size with a GC content of 67%, comprising 7543 genetic elements. Further genomic analysis showed that IAA biosynthesis in R74 involves the tryptophan side-chain oxidase (TSO) pathway and the tryptophan-independent pathway. Pot experiments revealed that inoculation with R74 increased the height, root length, stem diameter, and biomass of A. spinulosa seedlings. It also increased antioxidant enzyme activities, elevated soluble protein and chlorophyll contents, and reduced malondialdehyde levels. This study provides an empirical basis for the development of Burkholderia-based biofertilizers to promote A. spinulosa growth. Full article

Monacha cartusiana (O. F. Müller, 1774), native to the Mediterranean region and Europe, is a terrestrial gastropod recognized as a highly destructive agricultural pest that causes significant damage to crop plants, fruit trees, vegetables, ornamentals, and natural ecosystems. Despite its broad geographic distribution, the evolutionary history and phylogeographic relationships of M. cartusiana populations remain globally unexplored. This study reports the first molecularly confirmed record of M. cartusiana in Pakistan and investigates its genetic diversity and phylogeographic structure within a global context using mitochondrial markers. After morphological identification, genomic DNA was extracted from collected specimens using the CTAB method, followed by amplification and sequencing of the mitochondrial COI and 16S rRNA genes. The resulting sequences were subsequently analyzed using DnaSP and PopART software to estimate genetic diversity, perform neutrality tests, and construct haplotype networks. Published sequences of M. cartusiana retrieved from GenBank were incorporated to provide a global comparative framework. The COI dataset (555 bp) revealed 52 haplotypes, whereas the 16S rRNA dataset (269 bp) identified 14 haplotypes across global populations. High haplotype diversity (Hd = 0.946 for COI; Hd = 0.831 for 16S rRNA) and moderate nucleotide diversity (π = 0.010 for COI; π = 0.01253 for 16S rRNA) indicated substantial genetic variability within the species. Neutrality tests produced negative and insignificant values for Tajima’s D for COI and significant values for 16S rRNA (−1.428 for COI; −0.20586 for 16S rRNA) and Fu’s Fs (−29.776 for COI; −1.263 for 16S rRNA), suggesting historical population expansion. Phylogenetic reconstruction and haplotype network analyses identified two major clades (Clade A and Clade B), reflecting genetic relationships among populations from different geographic regions. AMOVA based on COI and 16S rRNA sequences revealed significant population structuring, with 29.98–51.30% of the total genetic variation occurring among populations and high fixation indices (FST = 0.299–0.51398, p = 0.001), indicating pronounced genetic differentiation and restricted gene flow. Pairwise FST analyses indicated that the Pakistani population is most closely related to populations from Italy and Central Europe, suggesting a closer genetic affinity with Southern or Central European populations. However, FST alone does not allow definitive inference of introduction directionality, and additional analyses would be required to robustly identify the source population. Overall, this study provides the first comprehensive molecular and phylogeographic assessment of the M. cartusiana species from Pakistan within a global context. These findings contribute important baseline data for understanding the evolutionary dynamics, dispersal history, and population connectivity of this economically important pest species. The pronounced genetic differentiation among populations and the suggested genetic affinity of the Pakistani population with European lineages have direct implications for biosecurity monitoring, invasion pathway tracing, and targeted pest management strategies. Future research integrating nuclear markers with the mitochondrial data presented here will be essential for a more complete understanding of gene flow and local adaptation in this species. Full article

Ilex rotunda Thunb. is a prestigious ornamental tree renowned for its vibrant red fruits, yet the molecular mechanisms governing its fruit color variation remain poorly understood. The discovery of a rare yellow-fruited natural bud sport cultivar, ‘Peace Time’, provides an ideal model to investigate these processes compared to the wild-type red fruit. In this study, we integrated physiological evaluations, untargeted metabolomics, and de novo transcriptomics across multiple fruit developmental stages to elucidate the basis of this color transition. Our results demonstrated that the yellow phenotype is characterized by high lightness and yellowness values, driven by the profound suppression of anthocyanin biosynthesis. Biochemical and transcriptomic profiling revealed that DFR (dihydroflavonol 4-reductase), a critical “gatekeeper” gene, experiences severe transcriptional silencing in the yellow-fruited cultivar. This enzymatic bottleneck triggers a “passive substrate overflow,” redirecting shared precursors toward the parallel flavonol branch, resulting in the substantial accumulation of specific flavonols, including rutin and isoquercitrin. Furthermore, correlation network analysis highlighted a putative dual regulatory module associated with this metabolic reprogramming: the down-regulation of the putative activator bHLH30 coupled with the robust up-regulation of the putative repressor bHLH51, together likely contributing to the silencing of DFR transcription. These findings provide a comprehensive “dual-module” and “passive overflow” framework for fruit coloration in I. rotunda, highlighting a remarkable metabolic plasticity that reshapes this cultivar’s phytochemical profile and offers vital insights for future ornamental breeding. Full article

Actinidia eriantha is an endemic kiwifruit species in China with high nutritional value and breeding potential. As a typical dioecious fruit tree, most currently bred cultivars are female, while the development of male pollinizer cultivars remains insufficiently studied and reported. Through long-term collection and evaluation of wild germplasm resources, our research team bred a male cultivar ‘Ganxiong 1’ with both ornamental and pollination value. In this study, the phenological traits, floral characteristics, major biological traits, ploidy levels, and genetic diversity of ‘Ganxiong 1’ were systematically analyzed and compared with those of the commonly used pollinizer ‘Moshan 4’. The results showed that ‘Ganxiong 1’ exhibited stable genetic traits, with branch bleeding occurring in late February and flowering in early May, highly overlapping with the flowering period of most female A. eriantha cultivars. It produced bright red flowers arranged in false dichasial cymes, showing high ornamental value. The average number of anthers per flower was 140.24, and the number of pollen grains per anther reached 8.57 × 10⁴, with a pollen viability of 97.64% and a pollen tube length of 127.25 μm, indicating strong pollination potential. Ploidy and SSR analyses revealed that ‘Ganxiong 1’ is a diploid cultivar and is genetically distinct from previously reported A. eriantha cultivars at the DNA level. Regarding pollination effects, the fruit set rate, single fruit weight, seed number, SSC, and AsA content of ‘Ganlv 1’ fruits pollinated with ‘Ganxiong 1’ were significantly higher than those pollinated with ‘Moshan 4’, while the TA content was significantly lower than that of ‘Moshan 4’ pollination. In conclusion, ‘Ganxiong 1’ exhibits high stability and distinctiveness in phenological, morphological, cytological, and genetic characteristics. It can be considered a new ornamental and pollination dual-purpose cultivar of A. eriantha and provides an important parental resource for kiwifruit breeding programs. Full article

Wild orchid populations are declining with intensified habitat fragmentation posing severe challenges to germplasm conservation. As an important ornamental Orchidaceae species, Cymbidium ensifolium has abundant germplasm resources and frequent natural and artificial hybridization. Long-term natural evolution and anthropogenic disturbance have led to complex genetic backgrounds and ambiguous phylogenetic relationships hindering accurate germplasm identification, elite resource excavation, and selective breeding. As a distinctive variety, Cymbidium ensifolium var. susin has great breeding potential. Clarifying its phenotypic and genetic characteristics is crucial for accelerating breeding progress. In this study, phenotypic determination, Hyper-seq reduced-representation genome sequencing, SNP/InDel genotyping, genetic diversity analysis, and core collection construction were used to evaluate the genetic diversity, population differentiation, and core germplasm screening of 13 Cymbidium ensifolium var. susin accessions. The results showed significant phenotypic differences and rich genetic variation among tested materials. Based on highly weighted floral traits, accessions were divided into three major phenotypic groups. At the molecular level, 963,239 SNP and 182,399 InDel loci were identified and mainly distributed in intergenic regions, followed by introns and exons. A phylogenetic tree was constructed from SNP loci combined with principal component and phenotypic clustering analyses. This study preliminarily clarified the genetic structure of pure-heart Cymbidium ensifolium var. susin, showing a distinct geographical pattern: “high consistency in Fujian and Guangdong; strong differentiation in Southwest China; and a transitional gradient in Central China”. Meanwhile, six core germplasm accessions were screened in this study, which provides a solid theoretical basis and material support for the conservation of pure-heart Cymbidium ensifolium var. susin accessions, variety improvement, hybrid parent selection, and molecular marker-assisted breeding. This is of great significance for promoting the innovation of Chinese orchid germplasm resources and the high-quality development of the industry. Full article

Tree architecture is a critical determinant of plant performance, light capture, biomechanical stability, and resource allocation. However, the multidimensional functional trait space and multiscale allometric scaling mechanisms underlying different architectural types in Malus remain poorly understood. This study investigates the multidimensional functional trait space and multiscale allometric scaling relationships among three typical architectural types (weeping, upright, and spreading) in Malus. A total of 206 germplasm accessions were analyzed by integrating nine core functional traits spanning macro-architectural, branch biomechanical, and leaf economic dimensions. Principal component analysis revealed that architectural differentiation is primarily driven by macro-architectural and branch biomechanical traits, alongside coordinated contributions from leaf economic traits. Functional diversity analysis indicated that the upright and spreading types exhibited higher functional richness, while the weeping type displayed the highest functional divergence but minimal or no functional overlap with the upright and spreading type, reflecting strong niche specialization under artificial selection. Multiscale allometric analyses demonstrated significant divergence in resource allocation strategies across hierarchical levels. At the whole-tree level, architectural types differed markedly in height–diameter and height–crown scaling relationships. At the branch level, conserved positive allometric scaling was observed, with the weeping type showing higher intercepts indicative of increased mechanical investment. At the leaf level, consistent negative allometry between petiole length and leaf area suggested optimized resource allocation for light capture. These pronounced differences suggest distinct ecological adaptation strategies: the weeping type prioritizes biomechanical compensation for pendulous branches and optimized light capture in loose canopies; the upright type emphasizes vertical light competition and mechanical compactness; the spreading type balances lateral expansion and spatial filling efficiency, reflecting differentiated resource allocation patterns shaped by artificial selection. Overall, this study reveals that tree architecture in Malus is shaped by coordinated trait interactions across multiple scales, leading to distinct ecological strategies and resource allocation patterns. These findings provide new insights into the structure–function co-evolution of woody plants and offer a theoretical framework for functional trait-assisted breeding of ornamental tree architectures. Full article

This study developed a comprehensive framework integrating ecosystem services (ESs), ecological adaptability, and ornamental value to guide tree species selection in historic cities constrained by soil salinization and subsurface heritage conservation. Taking Kaifeng, Henan Province, as a case study, we employed field surveys, i-Tree Eco, the Analytic Hierarchy Process, and K-means clustering to evaluate trees across protective, park, attached, and square green spaces. Results showed that carbon-related services dominated Kaifeng’s urban ES profile, with carbon storage (CS) and sequestration (CSE) value densities of 9.09 ¥·m⁻² and 0.84 ¥·m⁻²·y⁻¹, respectively. Air pollutant removal (AR) (0.21 ¥·m⁻²·y⁻¹) and P (0.009 ¥·m⁻²·y⁻¹) values remained comparatively low. Camphora officinarum Nees ex Wall delivered the highest annual ES value per tree (33.24 ¥·y⁻¹). Plaza greenery outperformed other space types in overall service provision, and deciduous broadleaf species generated greater ES value than evergreen conifers. Cluster analysis identified four functional groups: stress-tolerant pioneers, balanced adapters, high-efficiency carbon sinks, and ornamental specialists—each suited to specific green space contexts. This integrated framework offers a transferable approach for evidence-based tree selection in saline historic cities, supporting nature-based solutions in urban green space (UGS) planning. Full article

Horse chestnut (Aesculus hippocastanum L.) is a widely planted ornamental and urban tree valued for its aesthetic and ecological functions. In recent years, declining health of horse chestnut in urban environments has been increasingly reported, often associated with a complex of biotic and abiotic stressors. During a health survey of A. hippocastanum trees growing along an urban road corridor in Warsaw, Poland, extensive bark necrosis and branch dieback were observed. The aim of this study was to identify the causal agent of these symptoms using morphological, cultural, molecular (ITS rDNA), and pathogenicity tests under controlled conditions. Fungal isolates were obtained from necrotic tissues and were consistently identified as Kalmusia variispora based on ITS sequence analysis (99.0–99.6% similarity to GenBank references) and characteristic morphology. Pathogenicity tests fulfilled Koch’s postulates, reproducing necrotic lesions and cambial damage similar to those observed in the field. To our knowledge, this is the first documented report worldwide of K. variispora infecting A. hippocastanum. The findings expand the known host range of this opportunistic Didymosphaeriaceae species and highlight its potential role in bark and wood disease complexes of urban trees. Further research is needed to assess its distribution, genetic diversity, and epidemiological significance in urban forest ecosystems. Full article

Ipê trees (Bignoniaceae), mainly belonging to the genus Handroanthus, are widely used in urban landscaping and reforestation programs in Brazil. Anthracnose, typically associated with species of Colletotrichum, represents one of the major diseases affecting ipê seedlings and ornamental trees. However, the etiological agents involved have not yet been fully clarified using modern phylogenetic tools. In this study, we identified Colletotrichum species associated with anthracnose in ipê trees from Pernambuco, Brazil. A total of 22 isolates were obtained from symptomatic leaves of Handroanthus impetiginosus and H. chrysotrichus. Species identification was based on multilocus phylogenetic analyses using CAL, GAPDH, GS, and TUB2 loci. The isolates were assigned to three species: Colletotrichum siamense, C. tropicale, and C. karsti. Colletotrichum siamense was the most prevalent species (50%), followed by C. tropicale (36.3%), while C. karsti represented 13.7% of the isolates. Pathogenicity tests confirmed that all isolates were pathogenic to both ipê species, producing typical anthracnose symptoms. Aggressiveness differed between hosts, with H. impetiginosus showing higher susceptibility, as indicated by larger lesion development, whereas H. chrysotrichus exhibited lower disease aggressiveness. Thus, our findings represent the first multilocus-based identification of Colletotrichum species causing anthracnose in ipê trees, providing new insights into the diversity and epidemiology of this disease in urban environments. Full article

Euonymus bungeanus is a highly valued ornamental tree/shrub species widely utilized in landscaping and afforestation in Northeast Asia, yet molecular studies on this species remain limited due to the lack of validated reference genes for reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). In this study, 16 candidate reference genes were selected based on classical plant reference genes and our previous transcriptome data. Their expression stability was comprehensively evaluated using 64 samples collected from diverse tissues and plants subjected to various abiotic stress/hormone treatments across multiple time points. Across all samples analyzed, PBG1 (20S proteasome beta subunit G1) exhibited the highest overall expression stability, followed by VAPD (vacuolar ATP synthase subunit D) and EIF4A (eukaryotic translation initiation factor 4A). For tissue-specific analysis, TSR2 (pre-rRNA-processing protein), VAPD, and PBG1 demonstrated the greatest stability. Under specific stress conditions, PBG1 and EIF4A were identified as the most stable genes under low- and high-temperature conditions. PP2A (protein phosphatase 2A) and TUB6 (beta-6 tubulin) were optimal for drought stress, while TSR2, SRP (nuclear speckle splicing regulatory-like protein), and PBG1 exhibited superior stability under salt stress. These findings establish a validated panel of reference genes enabling accurate and reliable gene expression normalization in E. bungeanus, thereby facilitating future functional genomics studies in this economically and ecologically important species. Full article

Genetic diversity is fundamental for the conservation and sustainable utilization of plant species. Triadica cochinchinensis, a tree species native to southern China, is an important ornamental and nectar-producing plant with considerable economic value. However, the levels of genetic diversity and the patterns of population differentiation across its natural populations remain unexplored. Here, we developed 24 highly polymorphic SSR markers and used them to assess the genetic diversity and differentiation among 280 individuals collected from 10 natural populations of T. cochinchinensis. The results showed that the average expected heterozygosity (He) revealed by the SSR markers was 0.774, and the average Shannon diversity index (I) was 1.660, indicating a high level of genetic diversity at the species level of T. cochinchinensis. Analysis using SSR markers revealed a low average observed heterozygosity (Ho = 0.323) and a relatively high average inbreeding coefficient within populations (F = 0.466). These findings suggest that inbreeding is likely occurring, which may contribute to a loss of heterozygosity within the studied populations. Notably, not all populations had high genetic diversity. For example, the He of SC2 population (0.490), QY population (0.568), and SC1 population (0.585) were all below the mean He (0.607), suggesting that attention should be given to protecting populations with low genetic diversity. The results further showed that the average genetic differentiation coefficient (F_ST) between populations was 0.094, and the average gene flow (Nm) was 2.278, indicating that the natural populations of T. cochinchinensis had low genetic differentiation and relatively high gene flow. AMOVA indicated that 74% of the total variation was distributed within populations. Notably, populations SC1 and SC2 exhibited higher genetic differentiation from all others (F_ST > 0.1), which is likely attributed to mountain barriers restricting gene flow. Therefore, it is recommended to enhance in situ conservation efforts while also facilitating assisted gene flow, such as through artificial introduction. For the first time, this study reveals the genetic information of natural populations of T. cochinchinensis at the molecular level, thereby offering a valuable reference for the conservation and utilization of its germplasm resources. Full article

This study presents the vegetation of a Mediterranean area in Croatia, abandoned by the military three decades ago after two centuries of use. From 2023 to 2025, 97 phytosociological relevés were taken using the Braun–Blanquet approach. Based on numerical classification, we identified seven plant associations, two subassociations, and two communities within nine floristically and ecologically distinct vegetation classes. Military presence shaped the landscape in several ways. Large parts of the peninsula remain near-natural, covered by high maquis with minimal disturbance. Plateau shooting ranges, formerly grasslands, now represent rare habitats due to ongoing succession. Within former barracks, plantings included low-maintenance species providing rapid greening and visual screening. Evergreen conifers were favored for year-round greenery, while deciduous trees and ornamental shrubs provided shade and aesthetic value. Given current neglect and ongoing successional trends, the site requires a carefully planned management program aimed at habitat restoration, control of shrub encroachment, and maintenance of open and semi-open vegetation to preserve biodiversity and landscape heterogeneity. Full article

Optimizing public investment in urban green infrastructure under water scarcity is a core challenge in resource economics. Against the backdrop of global climate change—characterized by rising temperatures, increased frequency and intensity of droughts, and altered precipitation patterns—this study addresses the critical knowledge gap in quantifying the economic returns on the physiological adaptations of urban trees, which are central to their value as natural capital. We integrated dual-water isotope (δ²H, δ¹⁸O) and leaf carbon isotope (δ¹³C) analyses to mechanistically decode the water use strategy of Machilus yunnanensis (M. yunnanensis) in drought-prone Kunming, China. The results show strategic seasonal plasticity: a shift from shallow soil water (10–50 cm) in the wet season to deeper soil sources (50–90 cm) and stem reserves in the dry season, coupled with a dynamic, diurnally variable water use efficiency (WUE_13C). We then constructed a transparent economic valuation model translating these traits into three quantifiable benefit streams: (1) operational cost savings (EV₁) from reduced irrigation demand; (2) enhanced marginal productivity of water (EV₂) in ecosystem service generation; and (3) climate resilience value (EV₃) via mitigated mortality risk. Our “Water–Carbon–Economy” nexus framework provides a generalizable methodology for assessing the cost-effectiveness and risk-adjusted returns of urban forest species, demonstrating that tree selection based on such eco-efficient traits is not merely an ecological choice but a sound economic investment, offering direct implications for budget-constrained municipalities seeking to maximize green infrastructure benefits under climate uncertainty. Full article