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A longwave infrared quantum cascade laser with a peak wavelength of 10.5 μm is reported. The active region features a multi-miniband transition design for broad tuning operation. In pulsed mode and continuous wave mode, the maximum power of the Fabry-Pérot laser is 1.4 W and 0.32 W at room temperature, respectively. In the Littrow external cavity configuration, the wavelength of laser can be tuned in the ranges of λ ~ 8.59–9.67 μm and 10.20–10.68 μm at one fixed voltage of 12.6 V and 10.4 V, respectively, in pusled mode. [ABSTRACT FROM AUTHOR]

Vessel traits contribute to plant water transport from roots to leaves and thereby influence how plants respond to soil water availability, but the sources of variation in fine root anatomical traits remain poorly understood. Here, we explore the variations of fine root vessel traits along topological orders within and across tropical tree species. Anatomical traits were measured along five root topological orders in 80 individual trees of 20 species from a tropical forest in southwestern China. We found large variations for most root anatomical traits across topological orders, and strong co-variations between vessel traits. Within species, theoretical specific xylem hydraulic conductivity (K th) increased with topological order due to increased mean vessel diameter, size heterogeneity, and decreased vessel density. Across species, K th was associated with vessel fraction in low-order roots and correlated with mean vessel diameter and vessel density in high-order roots, suggesting a shift in relative anatomical contributors to K th from the second- to fifth-order roots. We found no clear relationship between K th and stele: root diameter ratios. Our study shows strong variations in root vessel traits across topological orders and species, and highlights shifts in the anatomical underpinnings by varying vessel-related anatomical structures for an optimized water supply. [ABSTRACT FROM AUTHOR]

The genus Dahlia has approximately 40 species; however, the complete chloroplast genome has been reported only for one species. Due to this lack of information on the chloroplast genomes, the phylogenetic relationships within the Dahlia genus remain unclear. Therefore, the present study sequenced the complete chloroplast genome of D. imperialis for the first time. This genome was 152,084 bp long with a typical quadripartite structure and a GC content of 38.45%. A total of 134 genes were annotated in the genome, including 86 protein-coding genes, 38 transfer RNA genes, 8 ribosomal RNA genes, and 2 pseudogenes. The detailed analysis identified UUA as the most frequently used codon and found 62 intergenic repeat sequences and 157 SSR loci in the D. imperialis genome. Phylogenetic analysis based on 49 chloroplast genomes showed that Dahlia was a monophyletic group, with D. imperialis positioned at the base of this clade. Network evolution and gene flow analysis unveiled extensive hybridization events within the Heliantheae alliance, especially in Dahlia. Thus, the comprehensive analysis of the complete chloroplast genome of D. imperialis enriches the information on the genetic resources of the Dahlia species, provides valuable information for reconstructing their phylogeny, and reveals the evolutionary dynamics of the Dahlia chloroplast genome. [ABSTRACT FROM AUTHOR]

Background: Non-suicidal self-injury (NSSI) and depression often co-occur among adolescents with more severe clinical symptoms. This study examined the network structures of NSSI and depressive symptoms in adolescents.Methods: Participants were recruited in the psychiatric outpatient clinics of three tertiary hospitals between April 10 and July 10, 2023. All participants been already found with self-injury behaviors in outpatient when enrolled. NSSI diagnostic criteria and Patient Health Questionnaire-9 (PHQ-9) were utilized to collect NSSI and depressive symptoms separately. We performed a network analysis to visualize the correlation between each symptom and to identify core and bridging symptoms in comorbidities.Results: A total of 248 patients were enrolled in the study, with a mean age of 15.48 (SD = 1.62). Based on the PHQ-9 scores and grades, our results showed that the incidence of depression in adolescents with non-suicidal self-injury behavior was relatively high (N=235, 94.76%), with the majority having severe depression. The network analysis revealed that nodes D-6 "feeling bad, failing or letting yourself or your family down", D-1 "little interest or pleasure" and D-4 "feeling tired" were the most vital and most central symptoms. The most crucial bridging symptom is the node NSSI-8 "frequent thinking about self-injury", which connects the NSSI to the depression comorbid network.Conclusion: This study offers a significant symptom-level conceptualization of the association between NSSI and depressive symptoms in a clinical sample of adolescents, which not only enhances our understanding of the comorbid but also identifies potential treatment targets to prevent and treat comorbidity between adolescent NSSI and depression. [ABSTRACT FROM AUTHOR]

In this research, we demonstrate a wavelength-stable continuous wave (CW) distributed feedback (DFB) quantum cascade laser (QCL) emitting at 7.2 μm using a surface metal grating approach without epitaxial regrowth. The deep metal grating provides an appropriate DFB coupling coefficient and enhanced thermal extraction, resulting in improved lasing performance and the realization of impressive wavelength stability. Quantitatively, the temperature tuning coefficient of the single-mode emission is only 0.54 nm/°C from 20 °C to 70 °C, and the current tuning coefficient of the single-mode emission is 3.2 nm/A from 1.0 A to 1.6 A. A DFB-QCL with a 2 mm cavity length exhibits a low threshold current of 0.6 A and a power of 1.1 W with a slope efficiency of 1 W/A in the CW mode at 300 K. A single-mode operation with a side mode suppression ratio of 33 dB and a single-lobed far-field without beam steering is obtained in the working temperature range of 20–70 °C The improved wavelength stability using a deep surface metal grating approach promises simplified fabrication, which is meaningful for the commercial applications of QCLs. [ABSTRACT FROM AUTHOR]

The high temperature may cause difficult growth or bloom in the summer, which is the key problem limiting the cultivation and application of dahlia. The photosynthetic physiological mechanisms of dahlia under high temperature stress were studied to provide a theoretical basis for expanding the application range of cultivation and annual production. Two dahlia varieties, 'Tampico' and 'Hypnotica Tropical Breeze', were used as test materials and were treated for 1 d or 2 d at temperatures of 35/30 °C or 40/35 °C (day/night: 14 h/10 h) and then recovered at 25/20 °C for 7 d. A 25/20 °C treatment was used as the control. The results are as follows: (1) High-temperature stress resulted in the chlorophyll (Chl) content, Fv/Fm, transpiration rate (Tr), net photosynthetic rate (Pn), and water potential decreasing significantly, and the Chl content, Tr, and stomatal density of 'Tampico' were higher than those of 'Hypnotica Tropical Breeze' during the same period. (2) After the two dahlia varieties were treated with high-temperature stress and recovered at 25/20 °C for 7 d, the plant morphology and various physiological indices under the 35/30 °C treatment gradually returned to normal, with 'Tampico' in better condition than 'Hypnotica Tropical Breeze'. (3) Both dahlia varieties could not withstand the stress of 40/35 °C for 2 days. [ABSTRACT FROM AUTHOR]

The use of neonicotinoid insecticides in agriculture has posed threats to ecological systems, and there is a need to assess the ecological risks of neonicotinoids from emission to nontarget organisms. We introduced a modeling approach to assess the ecological risks of neonicotinoids using honeybee and earthworm as model organisms, and the simulation was flexible under different environmental conditions. Using the cotton plant as an example, the simulation results demonstrated that under current recommended application rates, the use of common neonicotinoid insecticides posed no threat to earthworms, with the simulated risk quotients (RQs) much lower than 1. However, the simulation for some neonicotinoid insecticides (e.g., acetamiprid) indicated that using these insecticides on cotton plants could threaten honeybees, with simulated RQs higher than 1. The variability analysis showed that in high‐latitude regions, the unacceptable risk to honeybees posed by insecticide application can be further elevated due to cold, wet weather that results in relatively high insecticide levels in pollen and nectar. The model evaluation showed large overlaps of simulated risk intervals between the proposed and existing (BeeREX) models. Because the proposed and existing models have different simulation mechanisms, we recommend that these two models be used together to complement each other in future studies. Environ Toxicol Chem 2023;42:928–938. © 2023 SETAC [ABSTRACT FROM AUTHOR]

Dendrobium officinale Kimura et Migo is an orchid with both medicinal and edible values and a high economic value. The wild resources of D. officinale are in an endangered state. Compared with the wild D. officinale, cultivated D. officinale exhibits inferior quality and a low content of medicinal components. Polyploid induction is a conventional breeding tool for genome doubling of species, which can effectively increase the total amount of plant components to improve the medicinal efficacy of D. officinale. In this study, D. officinale tetraploids were generated by treating the protocorms with colchicine. Morphological observations showed that tetraploids exhibited decreased plant size and leaf shape index and increased stem diameter. Cytological observations showed that the polyploid plants had larger stomata and a lower number of stomata per unit area compared with normal plants. The highest stomata variation of 30.00% was observed when the plant was treated with 0.3% colchicine for 24 h. Chromosomal observations showed that treatment of plants with 0.2% colchicine for 48 h resulted in the highest tetraploid induction rate of 10.00%. A total of 10 tetraploids were successfully obtained by inducing plant protoplasts with colchicine. The number of diploid D. officinale chromosomes was 38 with a base number of 19, and the karyotype formula was 2n = 2x = 38 = 24m + 14sm with a karyotype asymmetry coefficient of 60.59%, belonging to type 2B. The number of tetraploid D. officinale chromosomes was 76 with a base number of 19, and the karyotype formula was 2n = 4x = 76 = 58m + 18sm with a karyotype asymmetry coefficient of 60.04%, belonging to type 2B. This study determined the optimal mutagenesis treatment based on the chromosome observation results, investigated the relationship between the phenotype and ploidy level, and generated the polyploid germplasm of D. officinale, thereby laying the foundation for the breeding of new D. officinale cultivars enriched with compounds of medicinal value. [ABSTRACT FROM AUTHOR]

We report a measurement of electron momentum distributions of valence orbitals of cyclopentene employing symmetric noncoplanar (e,2e) kinematics at impact energies of 1200 and 1600 eV plus the binding energy. Experimental momentum profiles for individual ionization bands are obtained and compared with theoretical calculations considering nuclear dynamics by harmonic analytical quantum mechanical and thermal sampling molecular dynamics approaches. The results demonstrate that molecular vibrational motions including ring-puckering of this flexible cyclic molecule have obvious influences on the electron momentum profiles for the outer valence orbitals, especially in the low momentum region. For π∗-like molecular orbitals 3a′′, 2a′′, and 3a′, the impact-energy dependence of the experimental momentum profiles indicates a distorted wave effect. [ABSTRACT FROM AUTHOR]

Orchids constitute approximately 10% of flowering plant species. However, only about 10 orchid genomes have been published. Metabolites are the main way through which orchids respond to their environment. Dendrobium nobile , belonging to Dendrobium , the second largest genus in Orchidaceae, has high ornamental, medicinal, and ecological value. D. nobile is the source of many popular horticultural varieties. Among the Dendrobium species, D. nobile has the highest amount of dendrobine, which is regarded as one of the criteria for evaluating medicinal quality. Due to lack of data and analysis at the genomic level, the biosynthesis pathways of dendrobine and other related medicinal ingredients in D. nobile are unknown. In this paper, we report a chromosome-scale reference genome of D. nobile to facilitate the investigation of its genomic characteristics for comparison with other Dendrobium species. The assembled genome size of D. nobile was 1.19 Gb. Of the sequences, 99.45% were anchored to 19 chromosomes. Furthermore, we identified differences in gene number and gene expression patterns compared with two other Dendrobium species by integrating whole-genome sequencing and transcriptomic analysis [e.g., genes in the polysaccharide biosynthesis pathway and upstream of the alkaloid (dendrobine) biosynthesis pathway]. Differences in the TPS and CYP450 gene families were also found among orchid species. All the above differences might contribute to the species-specific medicinal ingredient biosynthesis pathways. The metabolic pathway-related analysis will provide further insight into orchid responses to the environment. Additionally, the reference genome will provide important insights for further molecular elucidation of the medicinal active ingredients of Dendrobium and enhance the understanding of orchid evolution. [ABSTRACT FROM AUTHOR]

With over a millennium history of cultivation, Cymbidium species and hybrids is one of the most commercially important orchids in world floriculture industry. The Cymbidium genus has near 75 species with ornamental and medicinal importance and thousands of hybrids used for pot and cut flower production. Plant tissue culture techniques for breeding and large-scale propagation associated with greenhouses cultivation in sophisticated systems were used to accelerate the plant development until commercial flowering and aiming the high quality, uniformity and productivity of flowers. In this review, the overview picture in Cymbidium has been deeply discussed, such as diversity and ecology of species, karyotype characterization, identification and characterization of species and cultivars by molecular markers, aroma compounds biosynthesized in some species, micropropagation of species, somaclonal variation originated from clonal propagation and applications in breeding, production of biomass and bioactive compounds, omics approaches and symbioses of some species with a mycorrhizal fungus. The information presented here is useful to understand actual application of biochemical, biotechnological, cellular and molecular tools associated with ecology, breeding and propagation in Cymbidium species and cultivars. [ABSTRACT FROM AUTHOR]

As one of the largest families of angiosperms, the Orchidaceae family is diverse. Dendrobium represents the second largest genus of the Orchidaceae. However, an assembled high-quality genome of species in this genus is lacking. Here, we report a chromosome-scale reference genome of Dendrobium chrysotoxum, an important ornamental and medicinal orchid species. The assembled genome size of D. chrysotoxum was 1.37 Gb, with a contig N50 value of 1.54 Mb. Of the sequences, 95.75% were anchored to 19 pseudochromosomes. There were 30,044 genes predicted in the D. chrysotoxum genome. Two whole-genome polyploidization events occurred in D. chrysotoxum. In terms of the second event, whole-genome duplication (WGD) was also found to have occurred in other Orchidaceae members, which diverged mainly via gene loss immediately after the WGD event occurred; the first duplication was found to have occurred in most monocots (tau event). We identified sugar transporter (SWEET) gene family expansion, which might be related to the abundant medicinal compounds and fleshy stems of D. chrysotoxum. MADS-box genes were identified in D. chrysotoxum, as well as members of TPS and Hsp90 gene families, which are associated with resistance, which may contribute to the adaptive evolution of orchids. We also investigated the interplay among carotenoid, ABA, and ethylene biosynthesis in D. chrysotoxum to elucidate the regulatory mechanisms of the short flowering period of orchids with yellow flowers. The reference D. chrysotoxum genome will provide important insights for further research on medicinal active ingredients and breeding and enhances the understanding of orchid evolution. [ABSTRACT FROM AUTHOR]

Wolfberry Lycium, an economically important genus of the Solanaceae family, contains approximately 80 species and shows a fragmented distribution pattern among the Northern and Southern Hemispheres. Although several herbaceous species of Solanaceae have been subjected to genome sequencing, thus far, no genome sequences of woody representatives have been available. Here, we sequenced the genomes of 13 perennial woody species of Lycium, with a focus on Lycium barbarum. Integration with other genomes provides clear evidence supporting a whole-genome triplication (WGT) event shared by all hitherto sequenced solanaceous plants, which occurred shortly after the divergence of Solanaceae and Convolvulaceae. We identified new gene families and gene family expansions and contractions that first appeared in Solanaceae. Based on the identification of self-incompatibility related-gene families, we inferred that hybridization hotspots are enriched for genes that might be functioning in gametophytic self-incompatibility pathways in wolfberry. Extremely low expression of LOCULE NUBER (LC) and COLORLESS NON-RIPENING (CNR) orthologous genes during Lycium fruit development and ripening processes suggests functional diversification of these two genes between Lycium and tomato. The existence of additional flowering locus C-like MADS-box genes might correlate with the perennial flowering cycle of Lycium. Differential gene expression involved in the lignin biosynthetic pathway between Lycium and tomato likely illustrates woody and herbaceous differentiation. We also provide evidence that Lycium migrated from Africa into Asia, and subsequently from Asia into North America. Our results provide functional insights into Solanaceae origins, evolution and diversification. Cao, Li, et al. sequence 13 perennial woody plant species of Lycium, and specifically provide a draft assembly of L. ruthenicum and a chromosome-level assembly of L. barbarum, the wolfberry or Goji berry. From a phylogenetic tree the authors identify an ancient hexaploidization event, and report the evolution of gene families including fruit ripening, fruit coloration, polysaccharide synthesis and self-incompatibility within Solanaceae and the general biogeography of L. barbarum. [ABSTRACT FROM AUTHOR]

The binding energy spectrum and electron momentum profiles of the inner orbitals of methyl iodide have been measured using an electron momentum spectrometer at the impact energy of 1200 eV plus binding energy. Two peaks in the binding energy spectrum, arising from the spin-orbit splitting, are observed and the corresponding electron momentum profiles are obtained. Relativistic density functional calculations are performed to elucidate the experimental electron momentum profiles of two spin-orbit splitting components, showing agreement with each other except for the intensity in low momentum region. The measured high intensity in the low momentum region can be further explained by the distorted wave calculation. [ABSTRACT FROM AUTHOR]

Here an electron momentum spectroscopy study on the electronic structure of valence shell of iso-dichloroethylene molecule is reported. The experiment is carried out with a binary (e, 2e) spectrometer at incident electron energy of 1200 eV, employing noncoplanar symmetric arrangement. The binding energy spectra and electron momentum distributions (EMDs) of iso-dichloroethylene valence shell have been obtained. Theoretical EMDs are predicted with both Hartree-Fock and density functional theory methods, generally indicating good agreements with the measurement results. The interference effect is observed to significantly influence the EMDs of 2a2 and 5b2 Cl lone-pair orbitals. [ABSTRACT FROM AUTHOR]

In order to achieve a better accuracy-speed balance in the three-dimensional (3-D) deformation calculations of strip rolling, especially for cold rolling of comparatively thin and wide steel strips, a new integrative method is developed. The basic and related mathematic equations and the coupling algorithm are given in detail. To test the approach and prove its effectiveness, four examples are calculated by the proposed method and the models based on the traditional influence function method, taking a six-high strip finishing mill and the rolled piece of a certain specification as research objects. The lateral distributions of front tensile stress that is closely related to the 3-D plastic deformation of the rolled metal and the flatness in the four cases are presented and discussed. The comparison of computational expense and analysis of the results preliminarily confirms that it is workable for this purpose. [ABSTRACT FROM AUTHOR]

Purpose: Concentrations and distributions of polybrominated diphenyl ethers (PBDEs) were investigated in soils and plants from a closed deca-BDE manufacturing factory to evaluate and discuss their pollution level and distribution characteristics.Materials and methods: Eight PBDEs were analyzed in this study. The eight native PBDEs and 13C12-PCB209 (internal standard) were bought from Accustandard Inc. The eight 13C12-labeled PBDEs (isotope internal standard) were obtained from the Cambridge Isotope Laboratories, Inc. Soxhlet was chosen as the sample extraction method. The majority of lipid and pigment were removed by adding concentrated H2SO4 to each extract. Then, the concentrated extracts were further cleaned by multilayer silica gel columns. Finally, the eluants were concentrated to 1 mL. An internal standard was added to the final extract prior to the instrumental analysis. Extracts were determined by gas chromatography coupled to mass spectrometry in electron impact mode with DB-1 column.Results and discussion: Concentrations of PBDEs ranged from N.D. to 3.7 × 104 ng g−1 dry weight (dw) with the median concentrations from 0.60 to 1.17 × 104 ng g−1 dw. BDE-209 was the dominant congener in soils. The concentrations of PBDEs in different functional areas followed the order: manufacturing workshop (MW) → warehouse (WH) → administration area (AD). The levels of PBDEs were shown a decreasing tendency with the increase of the soil depth. However, different trends were observed between low-brominated BDE and high-brominated BDE. In plant samples, concentrations of ∑7 PBDEs (BDE-28, -47, -100, -99, -154, -153, -183) ranged from 7.89 to 1087.19 ng g−1 dw, and the concentrations of BDE-209 ranged from 2805.6 to 19,382.9 ng g−1 dw.Conclusions: The pollution level of PBDEs in the closed deca-BDE factory was lower than PBDEs of manufacturing factory, but higher than PBDEs of e-waste site and much higher than PBDEs of urban sites. The environmental risk caused by the residual of PBDE is of concern. This is the first research to study the pollution of PBDEs in soils and plants from a closed deca-BDE factory. [ABSTRACT FROM AUTHOR]

The genus Colletotrichum includes a number of important plant pathogens, which cause anthracnose diseases on a broad range of hosts in the world. In recent years, walnut has been severely damaged by anthracnose disease in China with significant yield losses. Thus, it is necessary to verify the etiology of anthracnose on walnut using both morphological and molecular approaches. In 2014, walnut fruits with anthracnose symptoms were collected from five walnut orchards in Shandong Province, China, and 24 isolates were isolated. Among them, six similar single-spore isolates obtained were used for pathogenicity testing of walnut anthracnose. Acervuli were brown, circular and the average size was 50.4-101.8 μm. Conidiophores were hyaline, septate, not branched or branching at the base, conidiogenous cells were enteroblastic, phialidic, hyaline, cylindrical, ampulliform. Conidia were single celled, smooth-walled with a large guttule, colorless, fusiform to cylindrical, and had obtuse to slightly rounded ends. The size of conidia was (11.6-)13-15(−16.2) × (4.1-)4.6-5.6(−6) μm. Appressoria were brown, ovoid to ellipsoid or slightly irregularly to irregularly shaped, and the average size was 6.8-9 × 5.1-6.5 μm. Pathogenicity of the isolates to fruits and leaves were compared, and genes from all six isolates were sequenced. The isolates were identified as C. siamense based on four-gene phylogenetic analyses (ribosomal DNA-ITS, GAPDH, ACT and CHS-1) and morphological as well as cultural characters. This is the first report of C. siamense as a causal agent of anthracnose of walnut in China. [ABSTRACT FROM AUTHOR]

Constituting approximately 10% of flowering plant species, orchids (Orchidaceae) display unique flower morphologies, possess an extraordinary diversity in lifestyle, and have successfully colonized almost every habitat on Earth. Here we report the draft genome sequence of Apostasia shenzhenica, a representative of one of two genera that form a sister lineage to the rest of the Orchidaceae, providing a reference for inferring the genome content and structure of the most recent common ancestor of all extant orchids and improving our understanding of their origins and evolution. In addition, we present transcriptome data for representatives of Vanilloideae, Cypripedioideae and Orchidoideae, and novel third-generation genome data for two species of Epidendroideae, covering all five orchid subfamilies. A. shenzhenica shows clear evidence of a whole-genome duplication, which is shared by all orchids and occurred shortly before their divergence. Comparisons between A. shenzhenica and other orchids and angiosperms also permitted the reconstruction of an ancestral orchid gene toolkit. We identify new gene families, gene family expansions and contractions, and changes within MADS-box gene classes, which control a diverse suite of developmental processes, during orchid evolution. This study sheds new light on the genetic mechanisms underpinning key orchid innovations, including the development of the labellum and gynostemium, pollinia, and seeds without endosperm, as well as the evolution of epiphytism; reveals relationships between the Orchidaceae subfamilies; and helps clarify the evolutionary history of orchids within the angiosperms. [ABSTRACT FROM AUTHOR]

Residues of polybrominated diphenyl ethers (PBDEs), including eight PBDE congeners, were investigated in soils and plants from a deca-BDE manufacturing factory located in the Shandong province of China to evaluate and discuss their pollution level and distribution. Total concentrations in topsoil ranged from 17.0 to 146 μg g dry weight (dw) with a mean value of 58.7 μg g dw. BDE-209 was the dominant congener in soils, accounting for 55.63-99.27 % of the total PBDEs. Concentrations and congener patterns in soils varied among different soil depths. Concentration levels in topsoil are high and the heavy accumulation in deep soil also can be observed, even for some sites, the concentrations in 50-100 cm depth are higher than in topsoil. In plant samples, total PBDE concentrations and the proportion of BDE-209 were high (69.92-99.10 %). The extent of pollution by PBDEs in the deca-BDE production factory was higher than in other regions, and the environmental risk caused by the production of deca-BDE is of concern. This is the first study to report pollution of PBDEs in soils and plants from the vicinity of a deca-BDE manufacturing factory. [ABSTRACT FROM AUTHOR]

The article focuses on a study on the preparation, characterization and adsorption properties of chitosan microspheres that were crosslinked by formaldehyde for copper(II) from aqueous solution. It stresses the importance of removing heavy metals such as copper from wastewater due to its toxicity. Chitosan is used in heavy metal removal for its metal-binding capacity and low cost. Copper(II) adsorption has been influenced by hydrogen-ion concentration (pH) and initial copper(II) concentration.

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]

Self-incompatibility (SI) is a type of reproductive barrier within plant species and is one of the mechanisms for the formation and maintenance of the high diversity and adaptation of angiosperm species. Approximately 40% of flowering plants are SI species, while only 10% of orchid species are self-incompatible. Intriguingly, as one of the largest genera in Orchidaceae, 72% of Dendrobium species are self-incompatible, accounting for nearly half of the reported SI species in orchids, suggesting that SI contributes to the high diversity of orchid species. However, few studies investigating SI in Dendrobium have been published. This study aimed to address the following questions: (1) How many SI phenotypes are in Dendrobium, and what are they? (2) What is their distribution pattern in the Dendrobium phylogenetic tree? We investigated the flowering time, the capsule set rate, and the pollen tube growth from the representative species of Dendrobium after artificial pollination and analysed their distribution in the Asian Dendrobium clade phylogenetic tree. The number of SI phenotypes exceeded our expectations. The SI type of Dendrobium chrysanthum was the primary type in the Dendrobium SI species. We speculate that there are many different SI determinants in Dendrobium that have evolved recently and might be specific to Dendrobium or Orchidaceae. Overall, this work provides new insights and a comprehensive understanding of Dendrobium SI. [ABSTRACT FROM AUTHOR]