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ABSTRACT Aim Location Time Period Major Taxa Studied Methods Results Main Conclusions Mycorrhizal fungi play key roles in the functioning of terrestrial ecosystems. The main types of mycorrhizal associations are arbuscular mycorrhizae, ectomycorrhizae, ericoid mycorrhizae and orchid mycorrhizae. Previous studies have shown that the abundance of plants with different types of mycorrhizal associations change gradually along latitudinal and altitudinal gradients driven by the effects of climate and soil nutrients. We aimed to understand how altitude and climatic and soil variables shape the distribution patterns of tropical plant mycorrhizal types and nitrogen‐fixing plants along altitudinal gradients in the Andes.Colombian Andean mountain range.Present day.Plants (vascular and non‐vascular).We used a herbarium plant records database and assigned mycorrhizal type to each plant species based on the available literature. Bioclimatic and soil variables were also compiled at a resolution of 10 km. We calculated the proportion of each mycorrhizal association type per grid cell and created a diversity index to explore their spatial distribution and association with abiotic factors based on LMs.The diversity of mycorrhizal associations increased with altitude and peaked around 3000 m, in an ecotone belt known as the subpáramo recognised by the high abundance of Ericaceae species. Soil carbon stock and soil total nitrogen were also positively correlated with the diversity of mycorrhizal types. Moreover, the abundance of arbuscular mycorrhizal plants was highest at low elevations and increased with the proportion of nitrogen‐fixing plants per cell.Our results indicate that mycorrhizal associations gradually change along altitudinal gradients in the tropical Andes. Climatic factors and the interactions between climatic and edaphic factors have the greatest explanatory power to predict the distribution of types of mycorrhizal associations along the altitudinal gradient. Based on these results we expect that climate change could potentially alter the distribution of mycorrhizal types in tropical mountains with unknown consequences for ecosystem functions. [ABSTRACT FROM AUTHOR]

Flowering plants are essentially sessile organisms that disperse their genes through pollination, expanding their areas of occurrence through seed dispersal. In orchids, seed dispersal is commonly mediated by air currents. Conversely, members of several genera have evolved seeds adapted to endozoochory. This is the case for Vanilla, the most economically important genus in the orchid family. The role of indehiscent fruits in the attraction and rewarding of Vanilla seed dispersers was investigated based on field observations, analysis of fragrances, reward substances, and investigation of seed viability through the digestive tract. Indehiscent Vanilla fruits are consumed exclusively by herbivores, i.e. agoutis. Besides providing nutritional rewards, the fruits are rich in polyphenols that are unpalatable to omnivores. The most dominant compound in fruits is attractive only to agoutis. This is the first study showing synzoochory in Orchidaceae and specificity of seed dispersal in orchids. Indehiscent fruits may have evolved early in Neotropical Vanilla in response to selection pressures mediated by large herbivores as the genus emerged ca. 34 Mya in South America, concomitantly with megafauna diversification in the Oligocene. Extinction of the megafauna during the Pleistocene has left agoutis as inheritors of seed dispersal in species with large fleshy fruits. Apart from the effects on omnivores, this study shows that indehiscent fruits of V. chamissonis are consumed exclusively by agoutis, providing the first evidence of target mutualism in orchid seed dispersal. [ABSTRACT FROM AUTHOR]

ABSTRACT Aim Location Taxon Methods Results Main Conclusions Endemic species, characterised by limited geographic ranges, face a high risk of extinction. The neotropical region harbours diverse ecosystems and a substantial number of endemic species, thus identifying areas of high endemism is crucial for protecting unique and threatened species and ecosystems. Vascular epiphytes—nonparasitic plants that grow on other plants without contact with the soil—exhibit remarkable diversity in the neotropics, with 63% of the global total of ca. 31,000 epiphyte species found in this region. This study aims to describe the endemism centres for the five most species‐rich families of vascular epiphytes.Neotropics.Tracheophyta.We gathered information from free‐access web repositories, specific epiphytic plant databases and scientific and grey literature on epiphyte species of the families Araceae, Bromeliaceae, Orchidaceae, Piperaceae and Polypodiaceae within the neotropical realm as defined by Morrone et al. (2022). Geographical ranges were calculated using minimum convex polygons for 11,446 species, accounting for about 70% of all epiphyte species in the neotropics. Narrow endemic species were defined as those within the first quartile of the density distribution of geographic range sizes within each family and we identified endemism centres for epiphyte species of the five families.Our study identified endemism centres for vascular epiphyte species in several biogeographic provinces, including Paramo, Cauca, Guatuso‐Talamanca, Atlantic, Yungas and Puntarenas‐Chiriqui. Orchidaceae, accounting for most of the analysed species (71%), drove the overall distribution pattern; however, endemism patterns varied among families.Regions with high epiphyte richness exhibited a greater proportion of endemic species, though the composition of epiphyte species varied considerably among regions. The endemism centres identified in this study could be prioritised as conserved and protected areas. [ABSTRACT FROM AUTHOR]

A new mycotrophic species of the genus Gastrodia (Orchidaceae), is described and illustrated from Arunachal Pradesh, India. The species is unique within the genus in having two oblong–linear calli which are parallelly arranged along the margins of the claw of the labellum, and white flowers. The new species is assessed as 'Endangered' according to the IUCN red list criteria. [ABSTRACT FROM AUTHOR]

Background: Phalaenopsis bellina, an orchid native to Borneo, is renowned for its unique appearance. It releases distinct fragrances, which have been linked to the presence of terpenoids. However, the identification and study of sesquiterpene synthase in P. bellina remain limited. In this study, we examines the functional characterisation of terpene synthase (TPS) from P. bellina, known as PbTS, through recombinant protein expression and its manifestation in the flower. Methods and Results: Gene annotation of PbTS revealed that the inferred peptide sequence of PbTS comprises 1,680 bp nucleotides encoding 559 amino acids with an estimated molecular mass of 65.2 kDa and a pI value of 5.4. A similarity search against GenBank showed that PbTS shares similarities with the previously published partial sequence of P. bellina (ABW98504.1) and Phalaenopsis equestris (XP_020597359.1 and ABW98503.1). Intriguingly, the phylogenetic analysis places the PbTS gene within the TPS-a group. In silico analysis of PbTS demonstrated stable interactions with farnesyl pyrophosphate (FPP), geranyl pyrophosphate (GPP), and geranylgeranyl pyrophosphate (GGPP). To verify this activity, an in vitro enzyme assay was performed on the PbTS recombinant protein, which successfully converted FPP, GPP, and GGPP into acyclic sesquiterpene β-farnesene, yielding approximately 0.03 mg/L. Expressional analysis revealed that the PbTS transcript was highly expressed in P. bellina, but its level did not correlate with β-farnesene levels across various flowering time points and stages. Conclusion: The insights gained from this study will enhance the understanding of terpenoid production in P. bellina and aid in the discovery of novel fragrance-related genes in other orchid species. [ABSTRACT FROM AUTHOR]

Summary: To evaluate the nutritional modes of orchids associated with 'rhizoctonia' fungi, analyses of hydrogen (δ2H), carbon (δ13C), and nitrogen (δ15N) stable isotope ratios are usually adopted. However, previous studies have not fully accounted for exchangeable hydrogens, which could affect these evaluations.Here, we performed standard δ13C, δ15N, and δ2H analyses on bulk samples. Additionally, we conducted δ2H analysis on α‐cellulose and cellulose nitrate samples to investigate whether the heterogeneity of exchangeable hydrogens among plant species influences the assessment of nutritional modes.The δ2H of orchids were consistently higher than those of surrounding autotrophic plants, irrespective of the three pretreatments. Although the rhizoctonia‐associated orchid exhibited lower δ13C, its δ2H was higher than those of the autotrophs. Notably, among all response variables, δ15N and δ2H exhibited high abilities for discriminating the nutritional modes of rhizoctonia‐associated orchids.These results indicate that a time‐efficient bulk sample analysis is an effective method for evaluating plant nutritional modes, as the heterogeneity of exchangeable hydrogens does not significantly impact the estimation. Using δ15N and δ2H benefits the assessment of partial mycoheterotrophy among rhizoctonia‐associated orchids. [ABSTRACT FROM AUTHOR]

ABSTRACT Aim Location Taxon Methods Results Main Conclusion Species with disjunct geographic distributions provide natural opportunities to investigate incipient or recent allopatric divergence. The combination of both genetic and ecological data may be fruitful to decipher the causes of such patterns: (i) actual vicariance, (ii) successful colonisation from one source to a new range (dispersal, biological introduction) or (iii) parallel convergent evolution.Southern France and Northern Spain.The bee orchid Ophrys aveyronensis (and its two recognised subspecies O. a. subsp. aveyronensis and O. a. subsp. vitorica) displays a disjunct geographic distribution with two subranges separated by 600 km on both sides of the Pyrenees mountain range.As allopatric divergence is often complex to document in the wild, we used a combination of population genomics and ecological niche modelling (ENM) to investigate the causes of this intriguing biogeographic pattern.The population genomic data demonstrate that all the studied populations exhibit similar patterns of genetic diversity and dramatic decrease in effective size compared with the ancestral population. Significant genetic differentiation and reciprocal monophyly exist between populations of the two subranges of O. aveyronensis, despite a very recent divergence time as young as ca. 1500 generations ago. Moreover, paleo‐ENM analyses support that the disjunct geographic distribution of O. aveyronensis is consistent with a range split of a broad ancestral range, contraction and distinct longitudinal and latitudinal shifts in response to climate warming during the Holocene.The congruence of the results obtained from both population genomics and ENM approaches documents how very recent continental allopatric divergence initiated speciation in this system. O. aveyronensis provides a promising opportunity to study the onset of reproductive isolation and parallel evolution following an initial stage of geographic separation in a group with high diversification rate. [ABSTRACT FROM AUTHOR]

Macodes limii J.J. Wood & A.L. Lamb is a terrestrial jewel orchid native to Sabah, recognised for its sparkling golden-yellow venations, uniformly distributed on its leaves. Despite its high ornamental value, the exploration of the plant's medicinal potential remains ambiguous. The current study was conducted to gain a fundamental understanding of the metabolite composition and regulation in M. limii plants from two different growing environments: wild and in vitro cultivation, as well as to analyse their phytochemical contents and antioxidant activity. The metabolite profiling of the M. limii plant extracts through gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis has tentatively identified compounds from various classes including sugars, carbohydrates, sugar alcohols, amino acids, organic acids, phenolic derivatives and lipid and lipid-like compounds. Subsequently, the multivariate statistical analysis confirmed the existence of significant metabolite variations across distinct growth environments. Notably, the leaf extract derived from wild-grown plants displayed the highest levels of total phenolic and flavonoid content, contributing significantly to its higher antioxidant activity as measured by the 2,2- diphenyl-1-picrylhydrazyl (DPPH) assay. The discovery has offered a fundamental understanding of the metabolites in M. limii jewel orchids, indicating that in vitro regenerated plants may represent a viable alternative for further investigating their therapeutic potential, thus helping to alleviate the impact on wild populations. [ABSTRACT FROM AUTHOR]

There are a number of rather anecdotal reports of plant growth on power cables in the Americas, but until now there has been no systematic attempt to gauge the geographical extension of this phenomenon nor a documentation of the diversity of species found there. Using observations from the participatory science data platform iNaturalist and the scientific literature, we document almost 700 occurrences of more than 40 species of vascular plants and three lichen species on power cables with a geographical distribution over 7000 km from the southern United States to northern Argentina. Based on these observations we discuss the ecological conditions of plant growth on power cables in terms of climate; elevational distribution; and the morphological, physiological, and life history traits that allow the observed set of species to thrive on this anthropic structure. [ABSTRACT FROM AUTHOR]

Aluminum-activated malate transporter (ALMT) genes play an important role in aluminum ion (Al3+) tolerance, fruit acidity, and stomatal movement. Although decades of research have been carried out in many plants, there is little knowledge about the roles of ALMT in Orchidaceae. In this study, 34 ALMT genes were identified in the genomes of four orchid species. Specifically, ten ALMT genes were found in Dendrobium chrysotoxum and D. catenatum, and seven were found in Apostasia shenzhenica and Phalaenopsis equestris. These ALMT genes were further categorized into four clades (clades 1–4) based on phylogenetic relationships. Sequence alignment and conserved motif analysis revealed that most orchid ALMT proteins contain conserved regions (TM1, GABA binding motif, and WEP motif). We also discovered a unique motif (19) belonging to clade 1, which can serve as a specifically identified characteristic. Comparison with the gene structure of AtALMT genes (Arabidopsis thaliana) showed that the gene structure of ALMT was conserved across species, but the introns were longer in orchids. The promoters of orchid ALMT genes contain many light-responsive and hormone-responsive elements, suggesting that their expression may be regulated by light and phytohormones. Chromosomal localization and collinear analysis of D. chrysotoxum indicated that tandem duplication (TD) is the main reason for the difference in the number of ALMT genes in these orchids. D. catenatum was chosen for the RT-qPCR experiment, and the results showed that the DcaALMT gene expression pattern varied in different tissues. The expression of DcaALMT1-9 was significantly changed after ABA treatment. Combining the circadian CO2 uptake rate, titratable total acid, and RT-qPCR data analysis, most DcaALMT genes were highly expressed at night and around dawn. The result revealed that DcaALMT genes might be involved in photosynthate accumulation. The above study provides more comprehensive information for the ALMT gene family in Orchidaceae and a basis for subsequent functional analysis. [ABSTRACT FROM AUTHOR]

Background and Aims The earliest-diverging orchid lineage, Apostasioideae, consists only of two genera: Apostasia and Neuwiedia. Previous reports of Apostasia nipponica indicated a symbiotic association with an ectomycorrhiza-forming Ceratobasidiaceae clade and partial utilization of fungal carbon during the adult stage. However, the trophic strategy of Neuwiedia throughout its development remains unidentified. To further improve our understanding of mycoheterotrophy in the Apostasioideae, this study focused on Neuwiedia malipoensis examining both the mycorrhizal association and the physiological ecology of this orchid species across various development stages. Methods We identified the major mycorrhizal fungi of N. malipoensis protocorm, leafy seedling and adult stages using molecular barcoding. To reveal nutritional resources utilized by N. malipoensis , we compared stable isotope natural abundances (δ 13C, δ 15N, δ 2H, δ 18O) of different developmental stages with those of autotrophic reference plants. Key Results Protocorms exhibited an association with saprotrophic Ceratobasidiaceae rather than ectomycorrhiza-forming Ceratobasidiaceae and the 13C signature was characteristic of their fully mycoheterotrophic nutrition. Seedlings and adults were predominantly associated with saprotrophic fungi belonging to the Tulasnellaceae. While 13C and 2H stable isotope data revealed partial mycoheterotrophy of seedlings, it is unclear to what extent the fungal carbon supply is reduced in adult N. malipoensis. However, the 15N enrichment of mature N. malipoensis suggests partially mycoheterotrophic nutrition. Our data indicated a transition in mycorrhizal partners during ontogenetic development with decreasing dependency of N. malipoensis on fungal nitrogen and carbon. Conclusions The divergence in mycorrhizal partners between N. malipoensis and A. nipponica indicates different resource acquisition strategies and allows various habitat options in the earliest-diverging orchid lineage, Apostasioideae. While A. nipponica relies on the heterotrophic carbon gain from its ectomycorrhizal fungal partner and thus on forest habitats, N. malipoensis rather relies on own photosynthetic carbon gain as an adult, allowing it to establish in habitats as widely distributed as those where Rhizoctonia fungi occur. [ABSTRACT FROM AUTHOR]

Tea gardens are the main economic backbone of the Terai & Dooars region and intermingle with forest areas of northern Bengal in India. The study aims to explore the vascular epiphytic diversity and their zone-wise assemblage pattern on 10 dominant shade trees in the tea gardens. Four years (March 2018-September 2022) of surveys recorded a total of 6,704 individuals that belong to 74 species of 20 families of vascular epiphytes. Considering life forms, the majority of them are holoepiphytes (62.16%), followed by hemiepiphytes (20.27%), accidental epiphytes (13.51%), and facultative epiphytes (2.7%). The predominantly recorded families are Orchidaceae (21 spp.), Araceae (11 spp.), Apocyanaceae with six species, and Piperaceae & Pteridaceae with three species each. Albizia lebbeck (L.) Benth. hosts a maximum of 737 vascular epiphytic assemblages (VEAs), whereas, Gmelina arborea Roxb. has a minimum of 450 VEAs. Vascular epiphytes were also studied for their host specificity using interpolation and extrapolation analyses. The findings of the study show that vascular epiphytic assemblage upon the shade trees of the tea garden has a remarkably high potential to contribute toward epiphytic diversity of this region other than forest and contribute significant ecological impacts. [ABSTRACT FROM AUTHOR]

Liparis gigantea is a Chinese traditional medicinal herb in the Orchidaceae family. It is a rare and special Liparis species that exhibits relatively large flowers. To illuminate its phylogenetic status and augment genomic resources, the complete chloroplast (cp) genome of L. gigantea was first sequenced and assembled using whole genome next-generation sequencing in this study. The cp genome size is 158,462 bp with a total GC content of 36.9%. Characterized by a quadripartite structure, the genome consists of a large single-copy (LSC) region of 86,032 bp, a small single-copy (SSC) region of 18,322 bp, which is separated by a pair of 27,054 bp inverted repeat regions (IRs). A total of 133 genes were annotated, including 87 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. Phylogenetic analysis strongly supported L. gigantea as the sister to two closely related terrestrial species, Liparis nervosa and L. vivipara. The results of this study provide genomic information for future research and application of this medicinal herb.

The orchid Calanthe discolor, which has high ornamental and medicinal value, is mainly distributed in Zhejiang, Jiangsu, and southeast Hubei Provinces of China, as well as in Japan and the southern Korean peninsula. In this study, the whole chloroplast genome sequence of C. discolor was first assembled using high-throughput Illumina paired-end technology, providing data to evaluate the evolution of this species. The C. discolor chloroplast genome was158,286 bp long, including a large single-copy region of 87,095 bp, a small single-copy region of 18,407 bp, and two copies of a repeat region (26,392-bp each). The overall G + C content was 41.2%. A total of 133 genes were predicted from the genome, including 87 protein-coding genes, eight ribosomal RNAs, 38 transfer RNAs. Phylogenetic analysis indicated a close relationship between C. discolor and C. bicolor.

In order to understand the bias and main affecting factors of codon usage in the plastid genome of Diplandrorchis sinica, which is a rare and endangered plant species in the Orchidaceae family, the complete plastid genome sequence of D. sinica was downloaded from the GenBank database and 20 protein-coding sequences that met the analysis requirements were finally selected. The GC content, length of the amino acid (Laa), relative synonymous codon usage (RSCU), and effective number of codon (ENC) of each gene and codon were calculated using the CodonW and EMBOSS online programs. Neutral plot analysis, ENC-plot analysis, PR2-plot analysis, and correspondence analysis were performed using Origin Pro 2024 software, and correlation analysis between various indicators was performed using SPSS 23.0 software. The results showed that the third base of the codon in the plastid genome of D. sinica was rich in A and T, with a GC3 content of 27%, which was lower than that of GC1 (45%) and GC2 (39%). The ENC value ranged from 35 to 57, with an average of 47. The codon usage bias was relatively low, and there was a significant positive correlation between ENC and GC3. There were a total of 32 codons with RSCU values greater than 1, of which 30 ended with either A or U. There were a total of nine optimal codons identified, namely, UCU, UCC, UCA, GCA, UUG, AUA, CGU, CGA, and GGU. This study indicated that the dominant factor affecting codon usage bias in the plastid genome of D. sinica was natural selection pressure, while the impact of base mutations was limited. The codon usage patterns were not closely related to gene types, and the distribution of photosynthetic system genes and ribosomal protein-coding gene loci was relatively scattered, indicating significant differences in the usage patterns of these gene codons. In addition, the codon usage patterns may not be related to whether the plant is a photosynthetic autotrophic or heterotrophic nutritional type. The results of this study could provide scientific references for the genomic evolution and phylogenetic research of plant species in the family Orchidaceae.

Abstract [Objective] A newly recorded orchid species, Gastrodia exilis Hook.f., was spotted from Yunnan Province, China, and its main characters were compared with its morphologically close relatives G. menghaiensis Z.H. Tsi & S.C. Chen, G. putaoensis X.H. Jin and G. dyeriana King & Pantl. [Methods] Morphological and anatomical observations of wild population specimens of the above species were carried out using a stereomicroscope, and photographs were taken with a close-up lens attached digital camera. [Results] G. exilis Hook.f. could be easily distinguished from those species by having a lip free of perianth tube, a disk with two conspicuous triangular lamellae near apex, and lobes of perianth tube crisped. [Conclusion] G. exilis Hook.f. is a newly recorded orchid species in China, and the discovery expands its distribution area and enriches the resources of wild orchids in China.

Societal Impact Statement The family Orchidaceae is renowned for its reliance on specialized pollinators and mycorrhizal symbioses. This study examined how the nonphotosynthetic orchid Gastrodia elata thrives on the dim forest floor, focusing on its pollination biology, particularly the chemical properties of pseudopollen and reproductive assurance mechanisms. It was found that G. elata mainly relies on Lasioglossum bees, attracted by its starch‐rich pseudopollen. Additionally, G. elata in the studied population can produce fruit through agamospermy (seeds from unfertilized ovules). Overall, the findings reveal that G. elata relies on fungi for nutrition and employs reproductive strategies such as mimicking pollen to attract bees and resorting to asexual reproduction when pollinators are scarce. Summary Mycoheterotrophy is an adaptation that allows survival in environments with low irradiance and minimal competition from autotrophic plants. However, such environments can negatively impact bee pollination, as most bees prefer open habitats. Despite this, the mycoheterotrophic orchid Gastrodia elata is known to rely on Lasioglossum bees for pollination. We investigated the reproductive biology of G. elata to understand how it overcomes pollinator limitation. Our research focused on the chemical composition and anatomical basis of G. elata pseudopollen (a substance that mimics pollen and may facilitate pollination), based on micromorphological and nutritional analyses, as well as observations of pollinator behavior. Additionally, we explored the potential presence of autogamy or agamospermy as mechanisms for reproductive assurance. The pseudopollen in G. elata originates from the disintegration of the adaxial parenchymatous tissue of the callus and is rich in starch. This contrasts with pseudopollen in most orchids, which typically originates from lip hairs and whose potential attractant is protein. Lasioglossum bees pollinating G. elata visit multiple flowers and actively collect pseudopollen. Furthermore, agamospermy serves as a reproductive safeguard in shaded habitats where insect‐mediated pollination is infrequent, at least in the investigated population. Our findings suggest that Gastrodia elata pseudopollen plays an important role in enhancing insect‐mediated pollination, particularly in relatively open habitats, while agamospermy ensures fruit set in shaded environments of the investigated population. Both pseudopollen production and agamospermy likely help overcome the pollination constraints posed by the mycoheterotrophic lifestyle.

Societal Impact Statement: The family Orchidaceae is renowned for its reliance on specialized pollinators and mycorrhizal symbioses. This study examined how the nonphotosynthetic orchid Gastrodia elata thrives on the dim forest floor, focusing on its pollination biology, particularly the chemical properties of pseudopollen and reproductive assurance mechanisms. It was found that G. elata mainly relies on Lasioglossum bees, attracted by its starch‐rich pseudopollen. Additionally, G. elata in the studied population can produce fruit through agamospermy (seeds from unfertilized ovules). Overall, the findings reveal that G. elata relies on fungi for nutrition and employs reproductive strategies such as mimicking pollen to attract bees and resorting to asexual reproduction when pollinators are scarce. Summary: Mycoheterotrophy is an adaptation that allows survival in environments with low irradiance and minimal competition from autotrophic plants. However, such environments can negatively impact bee pollination, as most bees prefer open habitats. Despite this, the mycoheterotrophic orchid Gastrodia elata is known to rely on Lasioglossum bees for pollination.We investigated the reproductive biology of G. elata to understand how it overcomes pollinator limitation. Our research focused on the chemical composition and anatomical basis of G. elata pseudopollen (a substance that mimics pollen and may facilitate pollination), based on micromorphological and nutritional analyses, as well as observations of pollinator behavior. Additionally, we explored the potential presence of autogamy or agamospermy as mechanisms for reproductive assurance.The pseudopollen in G. elata originates from the disintegration of the adaxial parenchymatous tissue of the callus and is rich in starch. This contrasts with pseudopollen in most orchids, which typically originates from lip hairs and whose potential attractant is protein. Lasioglossum bees pollinating G. elata visit multiple flowers and actively collect pseudopollen. Furthermore, agamospermy serves as a reproductive safeguard in shaded habitats where insect‐mediated pollination is infrequent, at least in the investigated population.Our findings suggest that Gastrodia elata pseudopollen plays an important role in enhancing insect‐mediated pollination, particularly in relatively open habitats, while agamospermy ensures fruit set in shaded environments of the investigated population. Both pseudopollen production and agamospermy likely help overcome the pollination constraints posed by the mycoheterotrophic lifestyle. [ABSTRACT FROM AUTHOR]

Abstract Background The disputed phylogenetic position of Aerides flabellata Rolfe ex Downie, due to morphological overlaps with related species, was investigated based on evidence of complete chloroplast (cp) genomes. The structural characterization of complete cp genomes of A. flabellata and A. rosea Lodd. ex Lindl. & Paxton were analyzed and compared with those of six related species in “Vanda-Aerides alliance” to provide genomic information on taxonomy and phylogeny. Results The cp genomes of A. flabellata and A. rosea exhibited conserved quadripartite structures, 148,145 bp and 147,925 bp in length, with similar GC content (36.7 ~ 36.8%). Gene annotations revealed 110 single-copy genes, 18 duplicated in inverted regions, and ten with introns. Comparative analysis across related species confirmed stable sequence identity and higher variation in single-copy regions. However, there are notable differences in the IR regions between two Aerides Lour. species and the other six related species. The phylogenetic analysis based on CDS from complete cp genomes indicated that Aerides species except A. flabellata formed a monophyletic clade nested in the subtribe Aeridinae, being a sister group to Renanthera Lour., consistent with previous studies. Meanwhile, a separate clade consisted of A. flabellata and six Vanda R. Br. species was formed, as a sister taxon to Holcoglossum Schltr. Conclusions This research was the first report on the complete cp genomes of A. flabellata. The results provided insights into understanding of plastome evolution and phylogenetic relationships of Aerides. The phylogenetic analysis based on complete cp genomes showed that A. flabellata should be placed in Vanda rather than in Aerides.

Dendrobium is the second largest genus of Orchidaceae, distributed in southern and southwestern China. The number of Dendrobium is large, but some taxa have not been discovered. During the investigation of orchid resources in Xizang, two Dendrobium species were discovered, which were identified as D. macraei Lindl. and D. ritaeanum King & Pantl. Both were recorded for the first time in China. The results are as follows: D. macraei is similar to D. plicatile, with the difference that the edge of the middle lobe of lip is entire, apex concave; D. ritaeanum is similar to D. angustifolium, the flowers of the former are very small, and sepals and petals do not have purple stripes, and the lip is triangular up to 1.4 cm in length. The detailed morphological characteristics and photographs of the two species are provided. The specimens are stored in the Herbarium of Xizang Agricultural and Animal Husbandry University. This discovery enriches the local data and the potential medicinal plant resource reserve of orchids in China, and is of great significance to the biodiversity study of orchids and the investigation of medicinal orchid resources.

It is challenging to make nocturnal observations of the natural behaviour of flower‐visiting moths as they are highly sensitive to visible artificial light sources. One solution, implemented here, is to use specially‐adapted close‐focusing camera traps that rely on infrared wavelengths for detection and illumination of small insect subjects. We investigated the pollination system of Bonatea saundersiodes, a rare African terrestrial orchid that is phylogenetically nested in the large Habenaria clade. We used modified camera traps and direct observations to study the pollination system of B. saundersioides. We quantified floral traits, including morphology, nectar, spectral reflectance and scent chemistry. Flowers of this orchid species were found to be pollinated exclusively by settling noctuid moths. Moth visits to the orchid were recorded throughout the night, with peaks of activity after dusk and just before dawn. Pollinaria of the orchid are attached between the palps of visiting moths. Floral traits generally consistent with settling moth pollination include the relatively short floral spurs (ca. 20 mm) containing small amounts of nectar, white and green perianth segments, and the floral scent which is produced at night and is dominated by β‐ocimene and other terpenoid compounds. This study demonstrates that close‐focusing camera traps have tremendous potential to improve our understanding of plant–pollinator interactions which are not easy to study using traditional methods. [ABSTRACT FROM AUTHOR]

Local adaptation is common in plant species, and knowing whether a population is locally adapted has fundamental and applied relevance. However, local adaptation in tropical plants remains largely less studied, and covering this gap is not simple since reciprocal transplantation – the gold standard for detecting local adaptation – is not feasible for most species. Here, we combined genetic, climatic and phenotypic data to investigate ecotypic differentiation, an important aspect of local adaptation, in coastal and inland populations of the orchid Epidendrum fulgens Brongn., a long‐lived tropical plant for which reciprocal transplantation would not be feasible. We used nine microsatellite markers to estimate genetic divergence between inland and coastal populations. Moreover, occurrence data and climate data were used to test for differences in the realized niche of those populations. Finally, we assessed saturated water content, leaf specific area, height, and stomatal density in common garden and in situ to investigate the effects of ecotypic differentiation and plasticity on the phenotype. Coastal and inland groups' niches do not overlap, the former occupying a wetter and warmer area. However, this differentiation does not seem to be driven by ecotypic differentiation since there was no positive correlation between genetic structure and climate dissimilarity. Moreover, specific leaf area and leaf saturated water content, which are important phenotypic traits related to soil fertility and drought stress, were rather plastic. We conclude that ecotypic differentiation is absent, since phenotypic plasticity is an important mechanism explaining the niche broadness of this species. [ABSTRACT FROM AUTHOR]

Background and Aims Structural colour is responsible for the remarkable metallic blue colour seen in the leaves of several plants. Species belonging to only ten genera have been investigated to date, revealing four photonic structures responsible for structurally coloured leaves. One of these is the helicoidal cell wall, known to create structural colour in the leaf cells of five taxa. Here we investigate a broad selection of land plants to understand the phylogenetic distribution of this photonic structure in leaves. Methods We identified helicoidal structures in the leaf epidermal cells of 19 species using transmission electron microscopy. Pitch measurements of the helicoids were compared with the reflectance spectra of circularly polarized light from the cells to confirm the structure–colour relationship. Results By incorporating species examined with a polarizing filter, our results increase the number of taxa with photonic helicoidal cell walls to species belonging to at least 35 genera. These include 19 monocot genera, from the orders Asparagales (Orchidaceae) and Poales (Cyperaceae, Eriocaulaceae, Rapateaceae) and 16 fern genera, from the orders Marattiales (Marattiaceae), Schizaeales (Anemiaceae) and Polypodiales (Blechnaceae, Dryopteridaceae, Lomariopsidaceae, Polypodiaceae, Pteridaceae, Tectariaceae). Conclusions Our investigation adds considerably to the recorded diversity of plants with structurally coloured leaves. The iterative evolution of photonic helicoidal walls has resulted in a broad phylogenetic distribution, centred on ferns and monocots. We speculate that the primary function of the helicoidal wall is to provide strength and support, so structural colour could have evolved as a potentially beneficial chance function of this structure. [ABSTRACT FROM AUTHOR]

Being one of the most abundant genera of orchids, Dendrobium presents a valuable genetic resource for hybridization programs. Morphological characterization and assessment of genetic parameters plays a crucial role in establishing genetic connections among orchid species within the same genus. The study aims to discern the morphological traits of five Indonesian Dendrobium species, intending to evaluate their potential as candidates for crossbreeding programs. The materials used in this study were D. antennatum, D. discolor, D. stratiotes, D. lineale, D. gouldii, and D. sylvanum. This research examines 21 quantitative traits and 21 qualitative morphological traits of the studied Dendrobium. The findings reveal variations in characters related to flowers, leaves, and pseudobulbs. The analysis of genetic parameters indicates the presence of genetic diversity in traits such as flower stalk length, length of inflorescence, flower series length, flower length, flower width, dorsal sepal width, lateral sepal width, petal length, petal width, labellum length, labellum width, and the number of florets. All observed traits demonstrate high heritability. So, the characters that have high genetic variability and heritability are valuable in selection criteria for plant breeding. [ABSTRACT FROM AUTHOR]

Premise: Salt tolerance has rarely been investigated regionally in the neotropics and even more rarely in Orchidaceae, one of the largest families. Therefore, investigating local adaptation to salt spray and its physiological basis in Epidendrum fulgens, a neotropical orchid species, brings important new insights. Methods: We assessed the degree of salt tolerance in E. fulgens by testing whether coastal populations are more tolerant to salt, which could point to local adaptation. To understand the physiological basis of such salt tolerance, we exposed wild‐collected individuals to salt spray for 60 days, then measured leaf expansion, osmotic potential, sodium leaf concentration, chlorophyll leaf index, chlorophyll fluorescence, relative growth rate, and pressure–volume curves. Results: There is no local adaptation to salt spray since both inland and coastal plants have a high tolerance to salt stress. This tolerance is explained by the ability to tolerate high concentrations of salt in leaf tissues, which is related to the high succulence displayed by this species. Conclusions: We showed an unprecedented salt tolerance level for an orchid species, highlighting our limited knowledge of that trait beyond the traditional studied groups. Another interesting finding is that salt tolerance in E. fulgens is linked to succulence, is widespread, and is not the result of local adaptation. We suggest that E. fulgens and its allied species could be an interesting group to explore the evolution of important traits related to tolerance to salt stress, like succulence. [ABSTRACT FROM AUTHOR]

n the Neotropics, the focus of apomictic studies predominantly centres on trees within the Brazilian savanna, characterized, mostly as sporophytic and facultative, associated with polyploidy and polyembryony. To enhance our understanding of the mechanisms governing apomixis and sexual reproduction in tropical herbaceous plants, we clarify the relationship between apomixis, chromosome counts, and polyembryony in the epiphytic orchid Zygopetalum mackayi , which forms a polyploid complex within rocky outcrops in both the Brazilian savanna and the Atlantic forest. To define embryo origins and describe megasporogenesis and megagametogenesis, we performed manual self-pollinations in first-day flowers of cultivated plants, considering all three cytotypes (2 x , 3 x , 4 x) of this species. Flowers and fruits at different stages were collected to describe the development and morphology of ovules and seeds considering sexual and apomictic processes. As self-pollination treatments resulted in high fruit abortion in diploids, we also examined pollen tube development in aborted flowers and fruits to search for putative anomalies. Megasporogenesis and megagametogenesis occur regularly in all cytotypes. Apomixis is facultative and sporophytic, and associated with polyploid cytotypes, while diploid individuals exclusively engage in sexual reproduction. Polyembryony is caused mainly by the production of adventitious embryos from nucellar cells of triploids and tetraploids, but also by the development of multiple archesporia in all cytotypes. Like other apomictic angiosperms within the Brazilian savanna, our findings demonstrate that apomixis in Z. mackayi relies on pollinators for seed production. We also consider the ecological implications of these apomictic patterns in Z. mackayi within the context of habitat loss and its dependence on pollinators. [ABSTRACT FROM AUTHOR]

Orchids are the most heavily traded plant group globally, putting pressure on wild populations in many source countries like the Philippines. Despite its rich orchid diversity, there remains a notable gap in understanding the factors driving orchid trade within the country. To address this knowledge gap and support orchid conservation efforts, we utilized a 5‐year orchid diversity dataset extensively collected through floristic field and village garden surveys in one of the largest key biodiversity areas in the southern Philippines. We employed a trait‐based approach to investigate ecological drivers of local orchid collection within this source area. Our results show that around 36% of local orchid diversity have predicted collection risks of ≥50%. Notably, locally collected orchid species exhibited multiple, large, and conspicuously colored flowers that are found in low‐elevation forests and higher up in forest stratum. Elevational distribution and flower size emerged as the strongest predictors, potentially influencing collection preferences. Our analysis of predicted collection risks underscores the vulnerability of both threatened and non‐threatened orchid species to local collection pressures. Moreover, we highlight the practical utility of our trait‐based approach in predicting risks and informing management strategies for local orchid conservation. This research marks a significant step toward identifying ecological drivers influencing orchid trade at its source, providing insights that can inform targeted conservation strategies across many key biodiversity areas for this highly diverse, charismatic, and threatened plant family. [ABSTRACT FROM AUTHOR]

AbstractDendroochreatene (1), a new phenanthrene derivative with a spirolactone ring, was isolated from the whole Dendrobium ochreatum plant together with 11 known compounds (2–12). The structure of the new compound was elucidated spectroscopically and phenolic compounds were firstly reported from D. ochreatum. Moscatilin (4), major compound isolated from D. ochreatum, was found to be cytotoxic toward H460 lung-cancer cells, with an IC50 value of 147.3 ± 0.9 µM, while loddigesiinol C (7), C-α-methoxy derivative was inactive. [ABSTRACT FROM AUTHOR]

2,7,2′-Trihydroxy-3,4,4′7′-tetramethoxy-1,1′-biphenanthrene (1), a previously undescribed biphenanthrene, and five known phenanthrenes, i.e. 2,5-dihydroxy-4-methoxy-9,10-dihydroxyphenanthrene (2), 2,4-dihydroxy −7-methoxy-9,10-dihydroxyphenanthrene (3), 7-hydroxy-2-methoxy-phenanthrene-1,4-dione (4), 7-hydroxy-2-methoxy-9,10-dihydro-phenanthrene-1,4-dione (5), and 4,4′,7,7′-tetrahydroxy-2,2′-dimethoxy-9,9′,10,10′-tetrahydro−1,1′-biphenanthrene (6) were isolated from the whole plant (stems, leaves, roots and fruits) of Liparis nervosa (Thunb.) Lindl., which is a medicinal plant of the genus Liparis in the Orchidaceae family. The structures of isolates were identified using spectroscopic methods, including NMR and mass spectrometry. Additionally, the cytotoxic potency of all the isolates against human lung cancer A549 cell line was evaluated by an MTT assay. All the isolated compounds showed cytotoxic activities with IC50 values in the range of 10.20 ± 0.81 to 42.41 ± 2.34 μM. The obtained data highlight the importance of L. nervosa as a source of natural lead compounds for cancer therapy. [ABSTRACT FROM AUTHOR]

The hyperdiverse orchid genus Bulbophyllum is the second largest genus of flowering plants and exhibits a pantropical distribution with a center of diversity in tropical Asia. The only Bulbophyllum section with a center of diversity inAustralasia is sect. Adelopetalum. However, the phylogenetic placement, interspecific relationships, and spatio-temporal evolution of this section remain largely unclear. To infer broad-level relationships within Bulbophyllum, and interspecific relationshipswithinsect. Adelopetalum, a genome skimmingdatasetwasgenerated for 89 samples, which yielded 70 plastid coding regions and a nuclear ribosomal DNA cistron. For 18 additional samples, Sanger data fromtwo plastid loci (matK and ycf1) and nuclear ITSwere added using a supermatrix approach. The study provided newinsights into broad-level relationships in Bulbophyllum, including phylogenetic evidence for the non-monophyly of sections Beccariana, Brachyantha, Brachypus, Cirrhopetaloides, Cirrhopetalum, Desmosanthes, Minutissima, Oxysepala, Polymeres, and Sestochilos. Section Adelopetalum and sect. Minutissima s.s. formed a highly supported clade that was resolved as a sister group to the remainder of the genus. Divergence time estimations based on a relaxed molecular clock model placed the origin of Bulbophyllum in the Early Oligocene (ca. 33.2 Ma) and sect. Adelopetalumin the Late Oligocene (ca. 23.6 Ma). Ancestral range estimations based on a BAYAREALIKE model identified the Australian continent as the ancestral area of the sect. Adelopetalum. The section underwent crown diversification fromthemid-Miocene to the late Pleistocene, predominantly in continental Australia. At least two independent long-distance dispersal events were inferred eastward from the Australian continent to New Zealand and to New Caledonia from the early Pliocene onwards, likely mediated by predominantly westerly winds of the Southern hemisphere. Retraction and fragmentation of the eastern Australian rainforests from the early Miocene onwards are likely drivers of lineage divergence within sect. Adelopetalum facilitating allopatric speciation. [ABSTRACT FROM AUTHOR]

Background: The disputed phylogenetic position of Aerides flabellata Rolfe ex Downie, due to morphological overlaps with related species, was investigated based on evidence of complete chloroplast (cp) genomes. The structural characterization of complete cp genomes of A. flabellata and A. rosea Lodd. ex Lindl. & Paxton were analyzed and compared with those of six related species in "Vanda-Aerides alliance" to provide genomic information on taxonomy and phylogeny. Results: The cp genomes of A. flabellata and A. rosea exhibited conserved quadripartite structures, 148,145 bp and 147,925 bp in length, with similar GC content (36.7 ~ 36.8%). Gene annotations revealed 110 single-copy genes, 18 duplicated in inverted regions, and ten with introns. Comparative analysis across related species confirmed stable sequence identity and higher variation in single-copy regions. However, there are notable differences in the IR regions between two Aerides Lour. species and the other six related species. The phylogenetic analysis based on CDS from complete cp genomes indicated that Aerides species except A. flabellata formed a monophyletic clade nested in the subtribe Aeridinae, being a sister group to Renanthera Lour., consistent with previous studies. Meanwhile, a separate clade consisted of A. flabellata and six Vanda R. Br. species was formed, as a sister taxon to Holcoglossum Schltr. Conclusions: This research was the first report on the complete cp genomes of A. flabellata. The results provided insights into understanding of plastome evolution and phylogenetic relationships of Aerides. The phylogenetic analysis based on complete cp genomes showed that A. flabellata should be placed in Vanda rather than in Aerides. [ABSTRACT FROM AUTHOR]

The Orchidaceae is a mega-diverse plant family with ca. 29,000 species with a large variety of life forms that can colonize transitory habitats. Despite this diversity, little is known about their flowering integrators in response to specific environmental factors. During the reproductive transition in flowering plants a vegetative apical meristem (SAM) transforms into an inflorescence meristem (IM) that forms bracts and flowers. In model grasses, like rice, a flowering genetic regulatory network (FGRN) controlling reproductive transitions has been identified, but little is known in the Orchidaceae. In order to analyze the players of the FRGN in orchids, we performed comprehensive phylogenetic analyses of CONSTANS-like/CONSTANS-like 4 (COL/COL4), FLOWERING LOCUS D (FD), FLOWERING LOCUS C/FRUITFULL (FLC/FUL) and SUPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) gene lineages. In addition to PEBP and AGL24/SVP genes previously analyzed, here we identify an increase of orchid homologs belonging to COL4, and FUL gene lineages in comparison with other monocots, including grasses, due to orchid-specific gene lineage duplications. Contrariwise, local duplications in Orchidaceae are less frequent in the COL, FD and SOC1 gene lineages, which points to a retention of key functions under strong purifying selection in essential signaling factors. We also identified changes in the protein sequences after such duplications, variation in the evolutionary rates of resulting paralogous clades and targeted expression of isolated homologs in different orchids. Interestingly, vernalization-response genes like VERNALIZATION1 (VRN1) and FLOWERING LOCUS C (FLC) are completely lacking in orchids, or alternatively are reduced in number, as is the case of VERNALIZATION2/GHD7 (VRN2). Our findings point to non-canonical factors sensing temperature changes in orchids during reproductive transition. Expression data of key factors gathered from Elleanthus auratiacus, a terrestrial orchid in high Andean mountains allow us to characterize which copies are actually active during flowering. Altogether, our data lays down a comprehensive framework to assess gene function of a restricted number of homologs identified more likely playing key roles during the flowering transition, and the changes of the FGRN in neotropical orchids in comparison with temperate grasses. [ABSTRACT FROM AUTHOR]

The reproduction of rare and endangered plant species is one of the most important factors determining the stability and survival of their populations, and knowledge of the barriers to successful reproduction is essential for species conservation. Habitat loss and slow reproduction due to low fruit set are usually considered the main threats to Cephalanthera longifolia and C. rubra (Orchidaceae). The aim of this study was to analyse the natural fruit set of these species during three consecutive years in Lithuania in the northern part of the temperate zone of Europe. Six populations of C. longifolia and three populations of C. rubra were studied each year from 2021 to 2023. During the study period, 49.3% to 54.4% of C. longifolia and 40.0% to 54.3% of C. rubra individuals produced no fruit. Over the three-year period, fruit set in individual populations of C. longifolia ranged from 5.2% to 19.5%, whereas fruit set in populations of C. rubra ranged from 4.1% to 18.8%. Significant weak or moderate correlations were found between plant height, inflorescence length and the number of flowers in the inflorescence and fruit set of both species. Flower position in the inflorescence had a significant effect on fruit set in both species, and the fruit set rate of lower flowers was higher than that of upper flowers. Significant but weak correlations were found between the fruit set and most of the environmental factors analysed. The results of this study suggest that the fruit set of C. longifolia and C. rubra is dependent on insect pollination of the flowers, which in turn is affected by habitat conditions. [ABSTRACT FROM AUTHOR]

The ARF gene family is a representative transcription factor that plays a crucial role in the regulation of various growth and development processes in plants. Although the ARF gene family has been identified in five Orchidaceae species, limited research has been conducted on the ARF gene within Dendrobium. To explore ARF family genes in different Dendrobium species, we selected chromosome-level genomic data from D. nobile, D. chrysotoxum, and D. huoshanense for genome-wide identification, and to analyze expression patterns in the D. nobile flower. In this study, 13, 18, and 23 ARF genes were identified in the genomes of D. chrysotoxum, D. huoshanense, and D. nobile, respectively. These genes were then subsequently classified into four classes (Classes I, II, III, and IV) based on our phylogenetic analysis. Additional protein sequence analysis found that 30 ARF proteins with three classically conserved structural domains (BDB, MR, and RD) were present in the three Dendrobium species. Our gene structure comparative analysis also found the same evolutionary branch with similar intron-exon structural features. Specifically, Class I and Class III display longer introns that potentially constitute a distinctive characteristic of Dendrobium. Gene expression patterns analysis showed the potential involvement of DnoARF 5, 7, 10, 11, 12, 13, 16, 17, and 23 in initial differentiation and flower bud formation. Likewise, transcriptomic analysis and RT-qPCR expression profiles indicated flower-specific expression patterns for four ARF genes (DnoARF5, DnoARF6, DnoARF16, and DnoARF22), which suggest an important impact on flower development and regulation. Ultimately, this study provides comprehensive data to elucidate the potential functions of ARF genes in three Dendrobium species and suggests new insights for further exploration concerning the function and regulatory mechanisms in Dendrobium during flower development. [ABSTRACT FROM AUTHOR]

Objective: To assess the number of terrestrial orchid species on the Tacaná volcano, Chiapas, and to empirically observe distribution/elevation patterns and ecological conditions. Design/Methodology/Approach: Random line transect sampling, over two years, for a total of 8 sites, each starting from the vicinity of rural villages. Samples were deposited in the CICY herbarium and analysed using dichotomous keys and field photographs. New records were compared with the GBIF data distribution. Results: 52 different taxa have been identified. 24 species are new records for the Soconusco region, where the Tacaná volcano is located. In this way, the Soconusco region becomes the richest Mexican region for the number of orchid species, joining a total of 351 species. Study Limitations/Implications: Building an accurate prediction model based on environmental and topographic variables could suggest microsites within the Tacaná Park that we have not visited for practical and technical reasons. Findings/Conclusions: The total number of taxa in the Soconusco region increases to 351. Terrestrial orchids are not usually studied in depth in tropical places, but they are also important in the ecological balance of the natural site. A specific inventory could show more richness of tropical ecosystems. [ABSTRACT FROM AUTHOR]

In this study, the morphological (plant height, leaf length and width, stem diameter and leaf number), anatomical (epidermal cell density and thickness, Stomatal length and width), photosynthetic (net photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentration, relative humidity, leaf temperature and chlorophyll fluorescence parameters) and biochemical parameters (the content of soluble sugar, soluble protein, proline, malondialdehyde and electrical conductivity) of Cypripedium macranthos Sw. in Changbai Mountain were determined under different light conditions (L10, L30, L50, L100). The results showed that morphological values including plant height, leaf area, stem diameter and leaf number of C. macranthos were smaller under the condition of full light at L100. The epidermal cell density and epidermal thickness of C. macranthos were the highest under L30 and L50 treatments, respectively. It had the highest net photosynthetic rate (Pn) and chlorophyll content under L50 treatment. Meanwhile, correlation analysis indicated that photosynthetically active radiation (PAR) and water use efficiency (WUE) were the main factors influencing Pn. C. macranthos accumulated more soluble sugars and soluble proteins under L100 treatment, while the degree of membrane peroxidation was the highest and the plant was severely damaged. In summary, the adaptability of C. macranthos to light conditions is ranked as follows L50 > L30 > L10 > L100. Appropriate light conditions for C. macranthos are 30%-50% of full light, which should be taken into account in protection and cultivation. [ABSTRACT FROM AUTHOR]

Aim: At fine scales (<10 km in spatial resolution), only a few studies have evaluated the relationships between abiotic factors and the horizontal occurrence of vascular epiphytes. At fine scales, variation in abiotic variables can be attributed to topographic heterogeneity. For example, air humidity and wind speed are likely to vary along ridge–valley gradients, and differences in slope aspect cause variation in light intensity as well as temperature gradient along an elevation. We tested the hypothesis that the horizontal epiphyte occurrence at fine scales is influenced more by topographic gradients related to abiotic factors than by host tree size and species. We also assessed air humidity variation along the ridge–valley gradient at our study site as a way to explore its possible correlation with the epiphyte occurrence. Location: A coniferous/broadleaf evergreen mixed forest in a humid temperate zone of Kochi, southwest Japan. Methods: We surveyed epiphyte occurrence on 310 trees and recorded host tree size and species within a 52‐ha watershed with an elevational range of 378–777 m a.s.l. Epiphyte occurrence was modeled using three topographic variables (ridge–valley gradient, slope aspect differences and elevational gradient), host tree size and species. The effect sizes of each variable were then compared. Air humidity was measured on the valley bottom, slope and ridge throughout the year. Results: Epiphyte occurrence probability increased toward the valley bottom and on larger host trees; it also varied among host tree species. Slope aspect differences and elevational gradient were less effective. The ridge–valley gradient had a greater effect than host tree size on epiphyte occurrence. Air humidity was highest at the valley bottom and lowest on the ridge. Conclusions: Horizontal epiphyte occurrence was driven more by topographic gradient than by host tree size and species in a small watershed covered by a warm‐temperate broadleaf forest. This finding suggests the importance of forests at valley bottoms to support epiphyte occurrence. [ABSTRACT FROM AUTHOR]

Aims: Despite the research on orchid in insular conditions, few studies are focused on the spatial distribution of their reproductive syndromes across complex insular systems. By using island species–area relationships (ISAR), we explore orchid biogeography in the Central Western‐Mediterranean islands. In this study, we aim to investigate variation in ISARs using orchid pollination mechanisms as proxies to establish permanent populations explaining how the c and z parameters of ISARs vary among island types and pollination strategies and defining the most influential factors in shaping orchids' distribution. Location: Mediterranean Basin. Taxon: Orchidaceae. Methods: Checklist of native orchids was obtained for 112 islands of Central‐Western Mediterranean Basin. The Arrhenius power function (S=c·Az) was used to fit ISARs for the total number of orchids as well as for functional groups defined by the pollination strategies, across different island types. We used GLM to investigate the relation between pollination syndromes with area and isolation as well as elevation, island origin, taxa richness of the source area and habitat diversity. Results: We found that ISARs differ between continental and volcanic islands depending on isolation. The z‐value was found to be higher for more specialized strategies while the c‐value increases from autogamy to allogamy, supporting the role of these two parameters in understanding distributional dynamics. Distance from the mainland is a negative predictor for all the strategies except when deception is decoupled; island area is a positive predictor only for allogamic, deceptive and food deceptive strategies, while habitat diversity is a positive predictor for allogamic, rewarding and deceptive strategies. Main Conclusions: Pollination syndromes contribute in explaining the distribution of orchids in insular conditions. Furthermore, we identified differences in ISARs across pollination syndromes in which the intercept increases when the pollination shifts from a generalist to a more specialized one. [ABSTRACT FROM AUTHOR]

Research on Satyrium nepalense var. ciliatum (Lindl.) Hook. f. has primarily focused on populations in Northwestern Yunnan, with limited studies on pollination syndromes and insect behavior. In addition, it is geographically limited in its breeding system studies. Here, pollination syndromes, florivory, and breeding systems of S. nepalense var. ciliatum from Liangwang Mountain (Central Yunnan, China) were investigated through field work, microscope, scanning electron microscope (SEM), and parafin section. It was revealed that the pollination syndrome was possessing out-crossing, such as bright color, a developed rostellum, nectar glands in the spur, and food hairs at the lip base. The color and nectar attracted flower visitors, and florivory was observed. Some flower visitors pollinated their companion species. Ants were identified as floral visitors for the first time in Satyrium, although substantial pollination was not observed. Ants might be potential pollinators. S. nepalense var. ciliatum possessed a mixed breeding system, including selfing, out-crossing, and apomixis, with apomixis being predominant in nature. It is suggested that the pollination syndrome, florivory, and pollination competition would contribute to its mixed breeding systems, particularly leading to the occurrence of apomixis. [ABSTRACT FROM AUTHOR]

Copyright of Flora Montibérica is the property of Flora Montiberica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Flora Montibérica is the property of Flora Montiberica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Caldasia is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Being one of the most abundant genera of orchids, Dendrobium presents a valuable genetic resource for hybridization programs. Morphological characterization and assessment of genetic parameters plays a crucial role in establishing genetic connections among orchid species within the same genus. The study aims to discern the morphological traits of five Indonesian Dendrobium species, intending to evaluate their potential as candidates for crossbreeding programs. The materials used in this study were D. antennatum, D. discolor, D. stratiotes, D. lineale, D. gouldii, and D. sylvanum. This research examines 21 quantitative traits and 21 qualitative morphological traits of the studied Dendrobium. The findings reveal variations in characters related to flowers, leaves, and pseudobulbs. The analysis of genetic parameters indicates the presence of genetic diversity in traits such as flower stalk length, length of inflorescence, flower series length, flower length, flower width, dorsal sepal width, lateral sepal width, petal length, petal width, labellum length, labellum width, and the number of florets. All observed traits demonstrate high heritability. So, the characters that have high genetic variability and heritability are valuable in selection criteria for plant breeding.

A taxonomical study of Sobralia decora and allied species recorded in South America is presented. The group is characterized by light pink to purple flowers, often with a white tip of the labellum and yellow to brown area on its throat. If considering the habit, the species can be recognized and distinguished from all other Sobralia species by producing keikis–stems arising from the old inflorescence. The similarity of the species forming the discussed complex caused numerous mistakes noticed in the literature and among the herbarium specimens. The aim of the elaboration is to clarify the differences allowing to determine the living and herbarium specimens with no errors.

Abstract Repetitive sequences can lead to variation in DNA quantity and composition among species. The Orchidaceae, the largest angiosperm family, is divided into five subfamilies, with Apostasioideae as the basal group and Orchidoideae and Epidendroideae showing high diversification rates. Despite their different evolutionary paths, some species in these groups have similar nuclear DNA content. This study focuses on one example to understand the dynamics of major repetitive DNAs in the nucleus. We used Next-Generation Sequencing (NGS) data from Apostasia wallichii (Apostasioideae) and Ludisia discolor (Orchidoideae) to identify and quantify the most abundant repeats. The repetitive fraction varied in abundance (27.5% in L. discolor and 60.6% in A. wallichii) and composition, with LTR retrotransposons of different lineages being the most abundant repeats in each species. Satellite DNAs showed varying organization and abundance. Despite the unbalanced ratio between single-copy and repetitive DNA sequences, the two species had the same genome size, possibly due to the elimination of non-essential genes. This phenomenon has been observed in other Apostasia and likely led to the proliferation of transposable elements in A. wallichii. Deep genome information in the future will aid in understanding the contraction/expansion of gene families and the evolution of sequences in these genomes.

The use of native species in landscaping has gained prominence due to their adaptability and sustainability compared to exotic species. To introduce a new plant into landscaping, it is necessary to define desirable ornamental characteristics. This study aimed to evaluate the ornamental potential and the feasibility of reintroducing the brazilian native orchid Brassavola tuberculata Hook. in natural environments, aiming for its use in sustainable landscaping with and without fertilization. The research was conducted in two main stages. In the first stage, the morphological characteristics of three individuals with floral buds were analyzed, focusing on quantitative aspects. The results showed that the species presents elegant inflorescences and fragrant flowers, with slightly yellowish white petals and a labellum articulated at the base. In the second stage, 20 plants originating from asymbiotic seeding, approximately 10 cm in height, were reintroduced into phorophytes of Hymenaea courbaril. A mixture of buriti palm fiber and coconut chips was used as the substrate. The plants were divided into two groups: one received 12 g of controlled-release fertilizer (NPK 15-15-15 + micronutrients) and the other received no fertilization. Evaluations were carried out on the day of reintroduction (day zero) and at 7, 14, 21, 30, 60, 90, 120, 180, and 360 days after reintroduction. The results indicate that the morphological aspects of B. tuberculata attribute ornamental potential to the species, and it can be successfully reintroduced into natural environments, even without fertilization. The plant demonstrated a remarkable ability to adapt and survive, reorganizing its metabolism to cope with initial stress.

Abstract This study aimed to evaluate the influence of culture media, irradiance, and sealing system on the in vitro and ex vitro growth of Cattleya walkeriana Gardner. We used MS medium as culture medium, supplemented with 30 g L-1 of sucrose and solidified with 7.0 g L-1 of bacteriological agar. This medium served as a control, while for the other treatments we supplemented the media as follows: 2) MS with 150 g L-1 of banana pulp = P150; 3) MS with 300 g L-1 of banana pulp = P300; 4) MS with 150 g L-1 of banana peel = PE150; and 5) MS with 300 g L-1 of banana peel = PE300. The irradiances were provided by 3000K LED lamps: 86 μmol m-2 s-1 (Irradiance-1) and 128 µmol m-2 s-1 (Irradiance-2) and the conventional sealing (CSS) and sealing systems that allow gas exchange (GESS). After 120 (in vitro) and 180 days (ex vitro) of cultivation, we evaluated them for pseudobulb (PN), leaf (LN) and root number (RN), plant height (PH), pseudobulb diameter (PD), longest leaf (LL) and root length (RL), fresh mass (TFM) and survival (%SURV). There was a significant interaction for all the variables analyzed. The CM x SS double interaction was significant for PH, LL, and RL. The CM x I x SS interaction was significant for PN, LN, RN, PD, TFM, and %SURV traits of C. walkeriana grown in vitro. There was a significant interaction between CM x I x SS for all C. walkeriana traits evaluated in ex vitro culture. Using the medium with up to 150 g L-1 of banana pulp combined with Irradiance-2 and CSS provided the highest values for in vitro plant growth. However, prior cultivation in MS medium, Irradiance-1, and CSS provided the greatest survival and establishment of this species plants in ex vitro culture.

Abstract Based on the research progress and traditional usage with whole herbal of the TCM "Tianma", chemical studies herein on the flower branch of Gastrodia elata were carried out in-depth and got 13 compounds including the gastrodinols (1–4), the flavonoid morins (5–8, 11–12), together with the specialist mulberrofurans (9, 13) and gastrodiamide (10) for the first time from the species. The antibacterial and cholinesterase inhibitory activities were then evaluated and the results showed that compounds 5, 11, 12, 13 have good activity against anti-methicillin-resistant Staphylococcus aureus, and compounds 9, 13 had good acetylcholinesterase inhibitory activity. All these results provide new chemical composition for better understanding the traditional application of "Tianma" and for exploring new pharmacological ingredients. Graphical Abstract