Search

Recent field work in Niue has recognised the terrestrial orchid Zeuxine vieillardii (Rchb.f.) Schltr. as indigenous. Zeuxine is a new genus for the flora of Niue, and brings the number of indigenous orchid genera to fifteen and the species to nineteen. Information is provided on the species biostatus, recognition, collections, distribution and habitats. Prior recognition of Z. vieillardii in Niue has been uncertain. In Flora of Fiji volume 5 (1991), Z. vieillardii (Rchb.f.) Schltr.was listed as being present in Niue but no specimen(s) cited. Later, in a 2011 field guide to the orchids of Tonga, Niue and Cook Islands there is no mention of Z. vieillardii in Niue. Based on collections made in 2024 from Niue, Z. vieillardii is known from an area near Matapa Chasm and Talava Arches, in the vicinity of Hikutavaka village, in the northwest region. Here it occurs in open, coastal forest, amongst exposed makatea outcrops. [ABSTRACT FROM AUTHOR]

Species with intermediate phenotypes are usually hypothesised to have originated from hybrid speciation. However, other mechanisms, such as double bifurcated speciation with introgression may create the same phenotypes. Clarifying the underlying process generating the observed intermediate morphology is important for conservation efforts, as it provides insights into the species' evolutionary background and adaptability. Here, we utilised genome‐wide single nucleotide polymorphism data to test evolutionary history models for Paphiopedilum wenshanense Z. J. Liu & J. Yong Zhang, an orchid species that is widely considered to be a hybrid with intermediate morphology of other two closely related species, P. concolor Pfitzer and P. bellatulum Pfitzer, distributed in Indochina. Our results rejected the hybrid speciation hypothesis and ascribed the intermediate floral phenotypes of P. wenshanese to introgression from P. concolor after it diverged from P. bellatulum during the last glacial maximum. Excluding the geographic covariate, the current genetic mixing rate of P. wenshanense from P. concolor is stronger in the south part of its range and is associated with precipitation in the early summer, indicating that population divergence in P. wenshanense is being driven by adaptive introgression. These genetic patterns also correspond to the observed floral variation across P. wenshaense populations. The introgression from P. concolor, along with the intermediate and varying floral morphologies, may expand the ecological opportunities for P. wenshanense, providing an explanation for why high genetic diversity has been maintained despite a high level of inbreeding and small census population size. Our study provides a framework for future research to investigate the characteristics and underlying mechanisms of intermediate morphologies in general. [ABSTRACT FROM AUTHOR]

Species are disappearing worldwide, and changes in climate and land use are commonly assumed to be the most important causes. Organisms are counteracting the negative effects of environmental factors on their survival by evolving various defence strategies, which positively affect their fitness. Here, the question addressed is: can evolution shape these defence strategies so that they positively affect the fitness of an organism? This question is complex and depends on the taxa and environmental factors. Therefore, here, only a special case of this question is studied in deceptive species of orchids: reproductive success (RS, ratio of the number of fruits to the number of flowers produced by a plant during the whole season), a commonly used measure of fitness is used to develop a model describing how RS affects the number of flowers, n, of a plant. This model predicts that: (i) the resulting relationship between RS and n is a positively skewed parabola, (ii) the distribution of the numbers of individuals with a specific number (n) of flowers, NI(n), also resembles a parabola and is also positively skewed, and that (iii) the peak of the distribution of NI is to the left of the peak of RS. A large set of data is presented that supports these predictions. If the data set is small, the concave positively skewed parabolic RS–n dependence is obscured by other factors. [ABSTRACT FROM AUTHOR]

Conventional orchid cultivation is thought to be ineffective and time-consuming. Simple tissue culture procedures are insufficient to increase orchid quality. The need for ongoing development can be met by integrating different plant breeding strategies in orchid tissue culture, such as induction mutation, elicitor addition, and genetic transformation. The purpose of this article was to report on current improvements in the use of plant breeding techniques to orchid tissue culture to increase orchid quality. This article referenced significant scientific publications. Orchid tissue culture using mutation induction is used to develop improved variations. Giving elicitors can cause orchid plants to conserve themselves and become more resistant to diseases. The required transgene can be introduced into the genome of cultivated orchids via Agrobacterium. These advancements have the potential to revolutionize orchid cultivation. [ABSTRACT FROM AUTHOR]

In response to the restrictions imposed by their epiphytic habit, orchids have developed structural traits that allow greater efficiency in water uptake and use, such as a complex adventitious root system with velamen. The composition of cell wall of this specialized epidermis can be altered according to the substrate to which it is fixed, influencing wall permeability, absorption, and storage of water in roots. The current study aimed to evaluate the cell wall composition of adventitious roots of Vanilla phaeantha (Orchidaceae) that grow attached to the phorophyte, fixed in the soil, or hung free. Immunocytochemical analyses were used to determine the protein, hemicellulose, and pectin composition of the cell walls of aerial and terrestrial roots. We observed that pectins are present in the different tissues of the aerial roots, while in the terrestrial roots, they are concentrated in the cortical parenchyma. The deposition of xyloglucans, extensins, and arabinogalactans was greater in the epidermis of the free side of the roots attached to the phorophyte. The strong labeling of pectins in aerial roots may be related to the influx of water and nutrients, which are generally scarce in this environment. The arrangement of hemicelluloses and proteins with the pectins may be associated with increased cell rigidity and sustainability, a feature of interest for the aerial roots. In summary, the habit of roots can interfere with the non-cellulosic composition of the cell walls of V. phaeantha, possibly related to changes in cell functionality. [ABSTRACT FROM AUTHOR]

Background: Orchids are well-known for their rich diversity of species as well as wide range habitats. Their floral structures are so unique in angiosperms that many of orchids are economically and culturally important in human society. Orchids pollination strategy and evolutionary trajectory are also fantastic human for centuries. Previously, OrchidBase was created not only for storage and management of orchid genomic and transcriptomic information including Apostasia shenzhenica, Dendrobium catenatum, Phalaenopsis equestris, and two species of Platanthera that belong to three different subfamilies of Orchidaceae, but explored orchid genetic sequences for their function. The OrchidBase offers an opportunity for the plant science community to compare orchid genomes and transcriptomes, and retrieve orchid sequences for further study. Description: Recently, three whole-genome sequences of the Epidendroideae species, Cymbidium sinense, C. ensifolium and C. goeringii, were sequenced de novo, assembled, and analyzed. In addition, the systemic transcriptomes of these three species have been established. We included these datasets to develop a new version of OrchidBase 6.0. Furthermore, four new analytical methods, namely regulation, updated transcriptome, advanced BLAST, and domain search, were developed for orchid genome analyses. Conclusion: OrchidBase 6.0 extended genetic information to that of eight orchid species and created new tools for an expanded community curation in response to the ever-increasing volume and complexity of data. [ABSTRACT FROM AUTHOR]

Superoxide dismutase (SOD) enzymes are essential for reducing oxidative damage resulting from overabundant reactive oxygen species under abiotic stress. While the SOD gene family has been extensively studied in many species, research focusing on Cymbidium species remains limited. In this study, a comprehensive analysis of the SOD gene family in three Cymbidium genomes was conducted. A total of 23 SOD genes were identified, with nine SODs in C. sinense, eight in C. ensifolium, and six in C. goeringii. These SOD genes were categorized into three clades: Cu/Zn-SOD, Fe-SOD, and Mn-SOD, with the Cu/Zn-SOD being the most abundant in these three types. This classification was supported by analyses of conserved domains, motifs, and phylogenetic relationships. Cis-element prediction showed that stress-responsive elements were identified in most SODs. Transcriptomic data revealed that seven CsSODs exhibited a border expression in all sequenced tissues, while two exhibited undetectable expression levels. Further qRT-PCR analysis showed that all CsSODs were upregulated under salt stress, with some exhibiting significant changes in expression. These findings all highlight the crucial role of CsSODs in the salt stress response and provide valuable insights for further breeding salt-tolerance varieties of C. sinense. [ABSTRACT FROM AUTHOR]

This study describes a new natural hybrid of Catasetum, C. x vilhenense, from the State of Rondônia (Brazil) found in ombrophilous forests near the Roosevelt River. The hybrid shows intermediate morphological features between its parental species, C. ariquemense and C. multifidum, with specific differences in floral morphology and inflorescence structure. We provide detailed data on its habitat, ecology, and geographic distribution, and a photographic plate of the hybrid. Given its restricted range, limited to a single locality with an area of occupancy (AOO) of less than 10 km2, C. x vilhenense may be Critically Endangered (CR) due to habitat loss and fragmentation. An identification key is also proposed for the species and natural hybrids of Catasetum with symmetrical and parallel antennae in the state of Rondônia, contributing to the understanding and classification of this genus in the Amazon forest. [ABSTRACT FROM AUTHOR]

Background and Aims Plant–fungus symbioses may experience temporal turnover during the ontogenetic or phenological development of the host, which can influence the ecological requirements of the host plant. In this study, we investigate temporal turnover of Ceratobasidiaceae orchid mycorrhizal fungal (OMF) communities in Prasophyllum (Orchidaceae), asking whether OMF communities are subject to temporal change attributable to orchid phenology or ontogeny. Methods Roots of adult Prasophyllum frenchii , Prasophyllum lindleyanum and Prasophyllum sp. aff. validum from Australia were sampled between autumn and spring. Seed was sown in situ as 'baits' to explore the mycorrhizal associations of germinating protocorms, which were compared with OMF in roots of co-occurring adult plants. Culture-dependent and -independent sequencing methods were used to amplify the internal transcribed spacer and mitochondrial large subunit loci, with sequences assigned to operational taxonomic units (OTUs) in phylogenetic analyses. Germination trials were used to determine whether fungal OTUs were mycorrhizal. Key Results A persistent core of OMF was associated with Prasophyllum , with Ceratobasidiaceae OMF dominant in all three species. Phenological turnover occurred in P. lindleyanum and P. sp. aff. validum , but not in P. frenchii , which displayed specificity to a single OTU. Ontogenetic turnover occurred in all species. However, phenological and ontogenetic turnover was typically driven by the presence or absence of infrequently detected OTUs in populations that otherwise displayed specificity to one or two dominant OTUs. Ex situ germination trials showed that 13 of 14 tested OTUs supported seed germination in their host orchid, including eight OTUs that were not found in protocorms in situ. Conclusions An understanding of OMF turnover can have practical importance for the conservation of threatened orchids and their mycorrhizal partners. However, frameworks for classifying OMF turnover should focus on OTUs important to the life cycle of the host plant, which we suggest are likely to be those that are frequently detected or functionally significant. [ABSTRACT FROM AUTHOR]

Abstract Paphiopedilum armeniacum, Paphiopedilum wenshanense and Paphiopedilum emersonii are critically endangered wild orchids. Their populations are under severe threat, with a dramatic decline in the number of their natural distribution sites. Ex situ conservation and artificial breeding are the keys to maintaining the population to ensure the success of ex situ conservation and field return in the future. The habitat characteristics and soil nutrient information of the last remaining wild distribution sites of the three species were studied. ITS high-throughput sequencing was used to reveal the composition and structure of the soil fungal community, analyze its diversity and functional characteristics, and reveal its relationship with soil nutrients. The three species preferred to grow on low-lying, ventilated and shaded declivities with good water drainage. There were significant differences in soil alkali-hydrolyzed nitrogen and available phosphorus among the three species. There were 336 fungal species detected in the samples. On average, there were different dominant groups in the soil fungal communities of the three species. The functional groups of soil fungi within their habitats were dominated by saprophytic fungi and ectomycorrhizae, with significant differences in diversity and structure. The co-occurrence network of habitat soil fungi was mainly positive. Soil pH significantly affected soil fungal diversity within their habitats of the three paphiopedilum species. The study confirmed that the dominant groups of soil fungi were significantly correlated with soil nutrients. The three species exhibit comparable habitat inclinations, yet they display substantial variations in the composition, structure, and diversity of soil fungi. The fungal functional group is characterized by a rich presence of saprophytic fungi, a proliferation of ectomycorrhizae, and a modest occurrence of orchid mycorrhizae. The symbiotic interactions among the soil fungi associated with these three species are well-coordinated, enhancing their resilience against challenging environmental conditions. There is a significant correlation between soil environmental factors and the composition of soil fungal communities, with pH emerging as a pivotal factor regulating fungal diversity. Our research into the habitat traits and soil fungal ecosystems of the three wild Paphiopedilum species has established a cornerstone for prospective ex situ conservation measures and the eventual reestablishment of these species in their native landscapes.

Many plant species orient their flowers to the Sun. Such orientations may be dynamic (heliotropism or solar tracking) or static, adopting fixed non-random azimuths to points on the daily arc of the Sun (conversotropism as defined herein). Two cauline greenhood orchid species, Diplodium reflexum and D. ampliatum (Pterostylidinae), are shown to be negatively conversotropic and non-heliotropic. Cauline greenhoods are trap and window flowers having large translucent light panels that glow when backlit flowers are viewed from the front. Conversotropism in greenhoods is thought to maximize light transmission through the window panels to manipulate the behaviour of fungus gnat pollinators. Conversotropism is so far documented in only seven species in five plant families, but is likely to be more widespread. The general characteristics of conversotropism are summarized and a new two stage model of window function in greenhoods is proposed. Window flowers in the Lady Slipper orchids (Cypripedium) and in Arums of the genus Arisaema are also predicted to be conversotropic. The evolution of conversotropism in cauline greenhoods highlights the importance of floral windows in these orchids. The highly unusual trap flowers may use light both as a pollinator attractant and repellent at different stages of the pollination process. Greenhoods appear to exploit the instinct of flies to escape confinement and the behaviours enabling it. This probably also applies to other trap flowers and adds insect escape behaviours to the many other drives, instincts, and behaviours exploited by plants for pollination. [ABSTRACT FROM AUTHOR]

Orchidaceae is one of the most prominent flowering plant families, with many species exhibiting highly specialized reproductive and ecological adaptations. An estimated 10% of orchid species in the American tropics are pollinated by scent-collecting male euglossine bees; however, to date, there are no published genomes of species within this pollination syndrome. In this study, we present the first draft genome of an epiphytic orchid from the genus Gongora , a representative of the male euglossine bee–pollinated subtribe Stanhopeinae. The 1.83-Gb de novo genome with a scaffold N50 of 1.7 Mb was assembled using short- and long-read sequencing and chromosome capture (Hi-C) information. Over 17,000 genes were annotated, and 82.95% of the genome was identified as repetitive content. Furthermore, we identified and manually annotated 26 terpene synthase genes linked to floral scent biosynthesis and performed a phylogenetic analysis with other published orchid terpene synthase genes. The Gongora gibba genome assembly will serve as the foundation for future research to understand the genetic basis of floral scent biosynthesis and diversification in orchids. [ABSTRACT FROM AUTHOR]

Abies nephrolepis Nature Reserve has complex habitats and rich species diversity but lacks systematic ecological surveys. We focused on Orchid in Abies nephrolepis Nature Reserve, investigated and analyzed Orchid diversity and changes in community structure according to the characteristics of the alpine valleys in the study area, in terms of altitude gradient and habitat type, using the sample line method and the quadrat method. The results showed that 11 genera and 13 species of Orchidaceae were found in the survey, among which the species richness of Malaxis monophyllos was the highest, Neottia puberula was the second highest, and the species richness of Tulotis ussuriensis was the lowest, and the species with relative plurality ≥ 10% were Malaxis monophyllos (51.69%), Neottia puberula (14.77%), and Cypripedium guttatum (11.15%). The results of diversity analysis showed that Orchidaceae species were rich and the diversity index were the highest in the middle altitude area of 1950–2250 m; the distribution of Orchidaceae in the low altitude area was obviously clustered, and the similarity with the high altitude area was low. With the increase in altitude, the number of species showed an increase and then a decrease, showing a single‐peak state, which was in line with the theory of "Intermediate altitude expansion hypothesis". The species and number of Orchidaceae in different habitats of Abies nephrolepis Nature Reserve also varied considerably, with Shannon‐Wiener diversity index being the highest in EV4 (Abies nephrolepis + Picea meyeri + Picea wilsonii + Larix gmelinii var. principis‐rupprechtii—Lonicera hispida—Carex lanceolata community) and EV5, and the smallest in EV1 habitats, Pielow evenness index being the highest in EV5 habitats and the lowest in EV1 habitats, and Simpson's index being the highest in EV5 habitats and the lowest in EV1 habitats. This study provides a scientific basis for strengthening regional monitoring of species diversity and protecting biodiversity. [ABSTRACT FROM AUTHOR]

Context: Global climate is changing rapidly, necessitating timely development of specific, actionable species conservation strategies that incorporate climate-change adaptation. Yet, detailed climate-change adaptation planning is noticeably absent from species management plans. This is problematic for restricted species, which often have greater extinction risk. Aims: Focusing on the restricted and endangered Tarengo leek orchid (Prasophyllum petilum), we aimed to adapt and test a framework for producing strategies for its management under climate change. Methods: We used expert elicitation to estimate the severity of threats and assess potential management actions to mitigate threat impacts. We created a conceptual model detailing ecology, threats and likely impacts of climate change on the species, including the interactions between components. Key results: Although climate change-related threats will affect the species, the most severe threats were non-climate threats including grazing, weeds, and habitat degradation. Fire management was deemed highly beneficial but had low feasibility for some populations. Without management, experts estimated up to a 100% decrease in one P. petilum population, and up to 50% decrease if management remained unchanged. Conclusions: Management actions with the highest benefit and feasibility addressed the non-climate threats, which, in turn, can give the species the best opportunity to withstand climate-change impacts. Experts highlighted the difficulty of addressing climate threats with such limited knowledge; therefore, further research was recommended. Implications: This adapted framework enabled a structured analysis of threats, and informed selection of priority adaptation options. We recommend its use for other restricted species for efficient and robust decision-making in climate-change management. Climate change is posing a significant extinction risk to rare and restricted species. Following consultation with species' experts, managers of the Tarengo leek orchid (Prasophyllum petilum) should address the region- or population-specific non-climate threats to increase its resilience to climate change. We present an adapted framework for incorporating climate-change adaptation into management, a critical tool for quantifying the severity of threats and assessing management actions for restricted species with highly specialised requirements. Photograph by Erika Roper. [ABSTRACT FROM AUTHOR]

The pollination characteristics and flowering phenology of Calanthe sieboldii were evaluated to elucidate its reproductive characteristics and breeding systems. Field observations and artificial pollination experiments were conducted to study the pollination biology in Xuancheng City, Anhui Province. Meanwhile, gas chromatography–mass spectrometry (GC-MS) was employed to analyze the species' volatile organic compounds (VOCs). Key findings include the following: (1) the flowering period extends from mid-April to mid-May, with a population-level flowering duration of 29 days in 2017, individual plant flowering averaging 20.22 days, and single flower longevity ranging from 12 to 23 days (mean = 19.30 days); (2) the species exhibits deceptive nectar guides devoid of nectar, indicating food-deceptive pollination, with Bombus sp. identified as its primary pollinator; (3) the pollinial–ovule ratio and hybridization index suggest a high level of self-compatibility without autonomous self-pollination, with no significant difference in pollination success between self- and outcross populations; (4) GC-MS analysis identified methyl benzoate and acacia-related compounds as the primary VOCs of C. sieboldii. These findings provide valuable insights into the conservation and sustainable management of orchids, particularly C. sieboldii. [ABSTRACT FROM AUTHOR]

Pollination success of alpine plants is often restricted by low and unpredictable pollinator activity because of harsh and unstable weather conditions, where nocturnal pollination is rare. The alpine orchid, Platanthera tipuloides (Orchidaceae), has inconspicuous greenish yellow flowers with a sweet scent and a long spur that contains nectar. These floral traits are expected to be related to nocturnal moth pollination. To elucidate the pollination mode and reproductive characteristics of this species, we measured floral traits (spur length, nectar content in the spur, floral scent), documented flower visitors using camera traps, and quantified self‐compatibility and the degree of pollen limitation through controlled pollinations at two study plots in the Taisetsu Mountains, northern Japan. It was revealed that P. tipuloides is self‐incompatible and pollen limitation was absent at one of the study plots. The flowers emitted more volatile substances during the night, including lilac aldehyde isomers, which are known to attract moths. A nocturnal moth, Entephria amplicosta, was observed foraging nectar from the flowers, while no diurnal visitors were observed. The proboscis of E. amplicosta was shorter than the spur length, but it was long enough to access the accumulated nectar in the spurs. These results suggest that nocturnal pollination by moths is possible and can be efficient even in an alpine ecosystem with harsh environmental conditions. [ABSTRACT FROM AUTHOR]

Orchids are one of the largest and globally distributed plant families. Indonesia has the most types of orchids, estimated around 20% from the total species across the world. Mainly orchids used as an ornamental plant. This research aimed to elucidate another potential of orchids as possibly for herbal medicine plant. The potential of orchids as herbal medicine has been known for a long time, but there is lack of well-documented research. The research method used in this research is exploration on predetermined research sites that were conducted in Mount Tilu, West Java on 2022. Observation data of orchids were collected on the sites and the analysis was carried out in a qualitative descriptive approach by describing the data from the research results and comparisons were made through a literature review. Based on the research results, we found about 31 species from 28 genera consisting of 24 epiphytic orchids and 7 terrestrial orchids in the Mount Tilu Kuningan area, West Java. There are 4 endemic species categorised in Java; Chilochista javanica, Crepidium koordesii, Crepidium junghuhnii, and Taeniophyllum biocellatum. [ABSTRACT FROM AUTHOR]

Summary: A new species of Cattleya ser. Parviflorae (Orchidaceae) is here described from the campos rupestres of the Diamantina Plateau, part of the Espinhaço Range, Minas Gerais, SE Brazil. The new species is named Cattleya attenboroughiana and it is here compared to the most similar taxa and illustrated with photographs. The new species is likely a microendemic but the available data is insufficient for a precise conservation status assessment, so we consider it Data Deficient (DD), reinforcing the need for further exploration in the Diamantina Plateau. [ABSTRACT FROM AUTHOR]

Summary: In this article we propose a new Catasetum species which presents affinity to the C. cristatum alliance, more specifically to species belonging to the C. barbatum complex. The new species has been found in the flooded forests of the Nhamundá River which constitutes the interstate limit between the States of Amazonas and Pará in Brazil. Plants were collected in flooded forest on the river's left bank, in the municipality of Faro (Pará State, Brazil). The new species is here described in detail and data on habitat, distribution, phenology, conservation status are presented, along with photographs. The new species is compared to C. garnettianum, C. nhamundaense and C. barbatum, from which it differs mainly in the lip structure. All of these allied species are part of the Catasetum barbatum species complex. We also provide an identification key for Catasetum species from the C. barbatum complex occurring in the Brazilian Amazon. [ABSTRACT FROM AUTHOR]

The orchid business in West Java can not be separated from the active role of the Indonesian Orchid Association (IOA). Currently, orchid business actors in this province have faced production problems due to their inability to meet market needs, both in quantity and quality. This study aims to identify orchid value chain management in IOA of West Java. The data collection utilized purposive and snowball sampling techniques. The respondents in this study consisted of six breeders, six growers (two seedlers and four juveniles-adults growers), six traders, and two employees of the Department of Food Crops and Horticulture of West Java. The data obtained were mapped using Porter’s value chain model. The research findings disclosed that the orchid value chain began with the procurement of inputs such as planting media, seeds, fertilizer, and pesticides. The production involved the in vitro production of plantlets using seeds obtained from crossbreeding and continued with plant enlargement. Adult and flowering plants were sold directly to consumers or through agents and traders. Two forms of governance existed within the orchid value chain. Market governance occurred between breeders and growers, growers and consumers, agents and traders, and traders and consumers. Whereas modular governance took place between breeders (imports) and industry, as well as the industry and agents. In conclusion, the value chain management of the IOA of West Java was not optimal due to the unimplemented application of tissue culture technology. Consequently, orchid production remained suboptimal and low level of orchid uniformity.

Shifts between pollinator functional groups can explain major changes in floral phenotype. I document a novel case of butterfly pollination in Platycoryne, an African genus that is phylogenetically embedded in the very large Habenaria clade in the Orchidaceae. Most Habenaria species have green or white flowers and many of these have been shown to be pollinated by moths, but my observations of the orange-flowered species Platycorynus mediocris in south-central Africa showed that it is pollinated diurnally by butterflies. The nectar-producing spurs of this species are c. 15 mm in length and closely match the tongue lengths of nymphalid and pierid butterflies that visit the flowers. The rostellum arms flank the spur entrance and place sickle-shaped pollinaria on the eyes or palps of the butterflies. In contrast to the highly scented flowers of moth-pollinated Habenaria species, the flowers of P. mediocris emit very little scent. Anecdotal observations indicate that several other Platycoryne species with orange flowers are also pollinated by butterflies. I conclude that the flower colouration (orange without UV reflectance) and low emission of scent in P. mediocris reflect an important historical shift to butterfly pollination in African members of the Habenaria clade. [ABSTRACT FROM AUTHOR]

In some biogeographic regions, many threatened plant species occur in habitats that periodically experience bushfire. However, we currently have relatively little information on how important plant–animal and plant–fungus interactions are affected by these fires. For the threatened sexually deceptive orchid Caladenia tessellata we test whether pollination rate, frequency of florivory, and the species of mycorrhizae the plant associates with differ between burnt and unburnt sites. Interestingly, pollination rates were unaffected by fire, demonstrating that populations of the thynnine wasp pollinator can persist post-fire. However, there was a significant negative relationship between number of flowers in a population and pollination success, which is likely a by-product of a deceptive pollination strategy. Despite the presence of vertebrate herbivores, florivory rates were low in both burnt and unburnt sites. Caladenia tessellata associated primarily with the mycorrhiza Serendiptia australiana , regardless of fire history. While our results suggest resilience to a one-off summer fire for the ecological interactions that we measured, it would be interesting to investigate the effects of fire frequency and time of year. High reproductive rates in small populations of C. tessellata suggest these populations may be viable and that retaining them is a high priority for conservation. [ABSTRACT FROM AUTHOR]

Orchids, renowned for their exquisite flowers and diverse growth habits, are a family of monocotyledonous plants with a global distribution. With an estimated 25,000-35,000 species worldwide, they demonstrate exceptional adaptability and ecological significance. Thriving in a wide range of environments, from sea level to high elevations, orchids can be found in tropical forests, semiarid regions, coastal areas, tundra, and even beyond the Arctic Circle. Notably, regions like India and Northeast China, particularly Arunachal Pradesh, are hotspots for orchid diversity, contributing significantly to their rich botanical heritage. For centuries, humans have been captivated by orchids' beauty, medicinal properties, and ecological importance. Beyond their essential primary metabolites, orchids produce a diverse array of secondary metabolites. These compounds, synthesized through specialized metabolic pathways, play crucial roles in plant defense, communication, and adaptation to various environmental stresses. This review explores the classification of secondary metabolites in medicinal orchids, including terpenoids, phenols, and nitrogen compounds, highlighting their structural and functional diversity. Their adaptations to abiotic stresses such as salinity, drought, cold, and heavy metals are discussed, emphasizing the important role of secondary metabolites in plant resilience. To cope with these and other stressors, Orchids, in particular, adapt through osmoregulation and secondary metabolite production, utilizing metabolic pathways like the Krebs cycle, the shikimate pathway, and the mevalonate and MEP pathways. This review provides a comprehensive overview of the significance, diversity, classification, adaptive strategies, and sustainable utilization of orchids through secondary metabolites. By understanding these fascinating plants, we can appreciate their ecological value and contribute to their conservation. [ABSTRACT FROM AUTHOR]

Prosthechea cochleata or clamshell orchid is recognized as a species of both conservation and commercial importance. It has long been prized by orchid breeders and growers for its unique flower and hardy disposition. The commercial market has failed to meet the demand for this species since it is still targeted for illegal collection in the wild. This study examines the effectiveness of the banana powder on two variants (var. diandra and var. triandra) with disparate home ranges and levels of genetic diversity using two commercially available agar-based media (PhytoTechnology P668 and P748). Undifferentiated protocorms of the two variants were monitored for shoot growth and differentiation across a period of 156 days. The growth media with 3% banana powder supplement (P748) was more effective in initiating shoot formation in both P. cochleata variants compared to control media (P668) (F = 27.15, p < 0.001, df = 81). The diandrous variant grown with banana showed the highest mean shoot count (28.67 shoots/flask) at the end of the monitoring period. Results suggest that banana supplement is an effective source of plant growth regulators and organic nutrients necessary to promote shoot formation and seedling development in this species. This research is important for the conservation of P. cochleata as it identifies an effective and cost-efficient method for in vitro propagation, which can aid in increasing the ex-situ and in situ populations of this threatened species. Additionally, the findings have implications for commercial orchid production, as it can potentially improve the cultivation and yield of this species for economic purposes. [ABSTRACT FROM AUTHOR]

Prescribed burning is a management tool used for both management of fuel loads and for ecological purposes across fire prone areas. While in temperate areas wildfires usually occur during the hottest summer months, prescribed burns are generally conducted in autumn and spring, when conditions are more suitable for controlling fire. Orchids maintain avoidance mechanisms, such as persisting as dormant tubers during the predominant fire season, and therefore may be at risk from prescribed burns occurring during their active life cycle period. Using a glasshouse experiment, we investigated the impacts of fire season on the Australian orchid species Pterostylis curta. This approach allowed us to i) implement seasonal burns and relate impacts to quantifiable above and belowground life cycle stages of the study species, ii) isolate and assess the role of smoke, and iii) control for fire intensity and life stage of the study species at each of the treatment levels to enable robust comparison focused on fire season effects. We found that late autumn burns caused complete failure of a cohort in our glasshouse study. Heat alone was not the driver of tuber mortality, because soil heating was similar across all burn seasons, and plants burnt in the three other seasons were able to re-emerge strongly in the growing season after fire. Furthermore, a lack of post-fire emergence was due to tuber mortality, not dormancy. Our results highlight that there is likely an interaction between fire-related heat and the life cycle stage at which burning occurs, especially replacement tuber initiation, that drives post-fire demography. We show that orchids like P. curta had the lowest risk of negative impacts when burnt in the later stages of their growing season, and that an understanding of finer-scale phenological cycles can inform more robust fire management of orchid species. [ABSTRACT FROM AUTHOR]

Malaxis acuminata D. Don (Common name- Jeevak) is a well-known medicinal herb with considerable therapeutic and medicinal potential. The species is used to cure ailments like seminal debility, fever, tuberculosis, vitality strengthening, and immune modulation. However, the phenology of this species has not been investigated systematically. In this study, eight major developmental stages for bud development (PGS-0), leaf development (PGS-1), shoot development (PGS-3), inflorescence emergence (PGS-5), flowering (PGS-6), fruit development (PGS-7), fruit maturation (PGS-8), and senescence (PGS-9) of M. acuminata have been identified using the extended Biologische Bundesantalt, Bundessortenamt und Chemische Industrie (BBCH) scale along with secondary growth stages. The climatic settings required for these phenophases of the species were also investigated. Malaxis acuminata exhibited a long juvenile vegetative phase compared to the short reproductive phase. For a better understanding of these growth stages, explanatory photographs with descriptions and codification are provided. It was observed that M. acuminata completes its various vegetative and reproductive phases in a very short period under favourable conditions, after which the pseudobulbs serve as propagation propagules for the production of plantlets in the following year. The correct identification of the phenophases of M. acuminata is vital for characterization, conservation and management because of their importance in cultivation and maintenance. Therefore, this approach can be recommended as an efficient tool for elite identification for growers and researchers for pharmaceutical and drug discovery, along with gene expression research. [ABSTRACT FROM AUTHOR]

The plastid-targeted transcription factor Whirly1 (WHY1) has been implicated in chloroplast biogenesis, plastid genome stability, and fungal defense response, which together represent characteristics of interest for the study of autotrophic losses across the angiosperms. While gene loss in the plastid and nuclear genomes has been well studied in mycoheterotrophic plants, the evolution of the molecular mechanisms impacting genome stability is completely unknown. Here, we characterize the evolution of WHY1 in four early transitional mycoheterotrophic orchid species in the genus Corallorhiza by synthesizing the results of phylogenetic, transcriptomic, and comparative genomic analyses with WHY1 genomic sequences sampled from 21 orders of angiosperms. We found an increased number of non-canonical WHY1 isoforms assembled from all but the greenest Corallorhiza species, including intron retention in some isoforms. Within Corallorhiza, phylotranscriptomic analyses revealed the presence of tissue-specific differential expression of WHY1 in only the most photosynthetically capable species and a coincident increase in the number of non-canonical WHY1 isoforms assembled from fully mycoheterotrophic species. Gene- and codon-level tests of WHY1 selective regimes did not infer significant signal of either relaxed selection or episodic diversifying selection in Corallorhiza but did so for relaxed selection in the late-stage full mycoheterotrophic orchids Epipogium aphyllum and Gastrodia elata. Additionally, nucleotide substitutions that most likely impact the function of WHY1, such as nonsense mutations, were only observed in late-stage mycoheterotrophs. We propose that our findings suggest that splicing and expression changes may precede the selective shifts we inferred for late-stage mycoheterotrophic species, which therefore does not support a primary role for WHY1 in the transition to mycoheterotrophy in the Orchidaceae. Taken together, this study provides the most comprehensive view of WHY1 evolution across the angiosperms to date. [ABSTRACT FROM AUTHOR]

Objective Wild Orchid resources in Dabieshan National Nature Reserve were investigated to provide references for Dabieshan National Nature Reserve protection and these resources utilization. [Method Based on a field invetigation and lieterature survey, we analyze the diversity and endangered level of Orchids in Dabieshan National Nature Reserve. [Result The results showed that there were 17 genera and 25 species of Orchids in the reserve. For life form, there were 17 species (68.00%) of terrestrial orchid, 5 species (20.00%) of epiphytic or- chid, and 3 species (12.00%) of saprophytic orchid. The Orchids were mainly distributed in Wujiashan, Tiantangzhai, Bodaofeng and Taohuachong area. For floristic types of genera, tropics was dominant with 8 genera (53.34%). There are 1 species of wild Orchids in national grade 1 and 8 species of wild Orchids in national grade II. [Conclusion] Some protection suggestions were put forward according to its current situation in the local area. [ABSTRACT FROM AUTHOR]

Orchids produce millions of dust-like and reserveless tiny seeds per capsule and are unable to germinate on their own in nature. Orchid seeds have developed strategies to exploit seed germination-promoting orchid mycorrhizal fungi (sgOMFs) for acquisition of exogenous nutrients to fuel germination. Once colonized by sgOMFs, orchid seeds can digest intracellular sgOMF hyphae to acquire fungal nutrients, especially those for carbon nutrition. However, the underlying carbon delivery pathway from sgOMFs to orchid cells remains elusive. Clarification of the identities of fungally derived carbohydrates and the main molecular players responsible for the sgOMF-to-orchid carbon flow is of great significance for better understanding of symbiotic germination. To germinate in nature, orchid seeds strictly rely on seed germination-promoting orchid mycorrhizal fungi (sgOMFs) for provision of carbon nutrients. The underlying delivery pathway, however, remains elusive. We develop here a plausible model for sugar transport from sgOMFs to orchid embryonic cells to fuel germination. Orchids exploit sgOMFs to induce the formation of pelotons, elaborate intracellular hyphal coils in orchid embryos. The colonized orchid cells then obtain carbon nutrients by uptake from living hyphae and peloton lysis, primarily as glucose derived from fungal trehalose hydrolyzed by orchid-specific trehalases. The uptake of massive fungally derived glucose is likely to be mediated by two classes of membrane proteins, namely, sugars will eventually be exported transporters (SWEETs) and H+-hexose symporters. The proposed model serves as a launch pad for further research to better understand and improve orchid seed germination and conservation. [ABSTRACT FROM AUTHOR]

Context: Australia has numerous threatened species of terrestrial orchid, with a particularly high incidence of rarity in the genus Prasophyllum R.Br. Although there has been research on mycorrhizal associations and propagation, little is known about the reproductive ecology of threatened Prasophyllum. Understanding which animals are responsible for pollination and the impact of herbivores on reproduction may inform conservation actions. Aims: For the nationally Critically Endangered Prasophyllum innubum , we aimed to determine the pollinator species, test for self-pollination, quantify levels of reproductive success and herbivory, and identify herbivores. Methods: Pollinator observations were undertaken at wild populations of P. innubum , whereas an experiment testing for self-pollination was undertaken in shadehouse conditions. We quantified reproductive success and herbivory at two populations and attempted to identify herbivores using game cameras. Key results: Pollination occurred via three species of bee and a sphecid wasp, all of which attempted feeding on floral nectar. Fruit set averaged 72–84% at wild sites, whereas only 6% of flowers set fruit via self-pollination when insects were excluded. Just 4% of inflorescences were completely consumed by herbivores, and no herbivory was captured on camera. Conclusions: P. innubum has a generalist rewarding pollination system that confers high levels of reproductive success, with herbivory having little impact on reproduction. Implications: Pollinator availability is unlikely to restrict conservation translocation site selection of P. innubum because of a generalist pollination system. If herbivores are a threat for this species, it is likely to be through alteration of habitat rather than direct grazing. For the Critically Endangered Prasophyllum innubum , pollination occurs via three species of bee and a sphecid wasp, suggesting a generalised strategy that may offer flexibility when selecting sites for conservation translocation. Fruit set averaged 72–84%, despite a minimal contribution from self-pollination. Only 4% of inflorescences were consumed by herbivores, meaning that if herbivores are a threat for this species, it is likely to be through alteration of habitat rather than direct grazing. Photograph by Tobias Hayashi. [ABSTRACT FROM AUTHOR]

The article presents a study which established a method for the propagation of Eulophia nuda Lindl, an endangered species belonging to the Orchidaceae family which has vast potential medicinal applications, through seed germination in vitro and embryogenesis. Topics include sterilization of the explant and inoculation, effect of plant growth regulators (PGRs) on embryogenesis, and effect of different media on seed germination and embryo formation.

Fluorinated cytokinins have emerged as promising alternatives to traditional cytokinins in Phalaenopsis plant tissue culture, offering enhanced stability and bioactivity. However, their metabolic fate and impact on endogenous cytokinin profiles remain largely unexplored. This study builds upon previous research to investigate the comparative metabolism of the traditional cytokinin 6-Benzylaminopurine (BA) with the successful alternatives 6-(3-fluorobenzylamino)purine (FmT) and 6-(3-fluorobenzylamino)purine 9-riboside (FmTR). Additionally, this study examines the impact of another crucial factor, the use of ventilated versus closed containers, on metabolic processes. The results revealed the distinct metabolic profiles associated with each treatment, highlighting the complex interplay between exogenous and endogenous cytokinin levels. This study is the first to investigate the effects of these stable, synthetic, and exogenous cytokinins on the naturally occurring cytokinin levels and their metabolites in micropropagated Phalaenopsis. Additionally, we proposed an alternative inactivation pathway involving the conversion of FmTR and BA to pT and pTR. These findings provide valuable insights into the intricate relationship between cytokinin metabolism and plant growth under in vitro conditions. [ABSTRACT FROM AUTHOR]

Determination of D. crumenatum mutant obtained from in vitro mutation breeding needs a long time due to its long-life cycle. SSR molecular markers can be used for early mutant detection. Specific SSR markers developed in D. crumenatum are not yet available. Alternative published SSR markers were developed from D. catenatum. The aims of this study are to screen the most informative SSR markers generated from D. catenatum tested in irradiated D. crumenatum population and to determine the gamma irradiation dose resulting the most mutants. Ten SSR markers were randomly selected and tested in 25 individuals of D. crumenatum plantlets irradiated with several doses (0, 5, 10, 15, and 20 Gy; 5 plantlets each dose). The result showed 7 of 10 primers were polymorphic and the other three were monomorphic. All seven polymorphic primers can be used to identified intraspecific variation in the D. crumenatum mutant population. Markers dnsr28 and dnsr98 were the most informative, with the highest polymorphic information content (PIC) value of 0.5. Irradiation D. crumenatum protocorms using 10-15 gray doses were detected as the highest mutant percentage obtained up to 100% in the sample tested. This resulting marker information can be used to screen wider mutant population to decrease the non-mutant individuals in the population for maintenance and cost efficiency. The 10-15 Gy can be used as reference doses for gamma irradiation in 3 months old D. crumenatum protocorm materials. [ABSTRACT FROM AUTHOR]

Orchids of the genus Paphiopedilum, also called slippers, are among the most valued representatives of the Orchidaceae family due to their aesthetic qualities. Due to overexploitation, deforestation, and illegal trade in these plants, especially in the vegetative phase, Paphiopedilum requires special protection. This genus is listed in Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora. Their precise identification is of great importance for the preservation of genetic resources and biodiversity of the orchid family (Orchidaceae). Therefore, the main objective of the study was to investigate the usefulness of the DNA barcoding technique for the identification of endangered orchids of the genus Paphiopedilum and to determine the effectiveness of five loci: matK, rbcL, ITS2, atpF-atpH and trnH-psbA as potential molecular markers for species of this genus. Among single locus barcodes, matK was the most effective at identifying species (64%). Furthermore, matK, ITS2, matK + rbcL, and matK + trnH-psbA barcodes can be successfully used as a complementary tool to identify Paphiopedilum orchids while supporting morphological data provided by taxonomists. [ABSTRACT FROM AUTHOR]

Vegetative growth of Cattleya orchids is influenced by environmental factors. In addition, growth and development are also determined by the availability of nutrients and hormones. One of the methods to accelerate the vegetative growth of orchids is by the application of NPK fertilizers and plant growth regulators such as benzyl amino purine (BAP). The objective of this study was to obtain the best concentration of NPK and BAP concentration on the vegetative growth of Cattleya orchids. The experiment was conducted at the screenhouse of the Experimental Garden of Bale Tatanen, Faculty of Agriculture, Padjadjaran University with a Factorial Randomized Block Design consisting of two factors, namely the concentration of NPK fertilizer (0, 1, 2, 3, and 4 g L-1 of NPK-28:10:10 and 2 g L-1 of NPK-32:10:10 as positive control), and the second factor was BAP concentration (0, 0.5 and 1 mg L-1) with three replications. The results showed that there was an interaction effect between the application of 2 g L-1 of NPK 28:10:10 and 1 mg L-1 BAP on the number of pseudobulbs per clump. Independently, the treatment of 2 g L-1 of NPK 28:10:10 showed the best results in the increase of plant height and the number of new shoots. While 0.5 mg L-1 of BAP showed the best results in the increase of plant height, the number of new shoots and the SPAD value.

Summary Recent studies on co-transformation of the growth regulator, TaGRF4-GIF1 chimera (Growth Regulating Factor 4-GRF Interacting Factor 1), in cultivated wheat varieties (Triticum aestivum), showed improved regeneration efficiency, marking a significant breakthrough. Here, a simple and reproducible protocol using the GRF4-GIF1 chimera was established and tested in the medicinal orchid Dendrobium catenatum, a monocot orchid species. TaGRF4-GIF1 from T. aestivum and DcGRF4-GIF1 from D. catenatum were reconstructed, with the chimeras significantly enhancing the regeneration efficiency of D. catenatum through in planta transformation. Further, mutating the microRNA396 (miR396) target sites in TaGRF4 and DcGRF4 improved regeneration efficiency. The target mimicry version of miR396 (MIM396) not only boosted shoot regeneration but also enhanced plant growth. Our methods revealed a powerful tool for the enhanced regeneration and genetic transformation of D. catenatum.

Superoxide dismutase (SOD) enzymes are essential for reducing oxidative damage resulting from overabundant reactive oxygen species under abiotic stress. While the SOD gene family has been extensively studied in many species, research focusing on Cymbidium species remains limited. In this study, a comprehensive analysis of the SOD gene family in three Cymbidium genomes was conducted. A total of 23 SOD genes were identified, with nine SODs in C. sinense, eight in C. ensifolium, and six in C. goeringii. These SOD genes were categorized into three clades: Cu/Zn-SOD, Fe-SOD, and Mn-SOD, with the Cu/Zn-SOD being the most abundant in these three types. This classification was supported by analyses of conserved domains, motifs, and phylogenetic relationships. Cis-element prediction showed that stress-responsive elements were identified in most SODs. Transcriptomic data revealed that seven CsSODs exhibited a border expression in all sequenced tissues, while two exhibited undetectable expression levels. Further qRT-PCR analysis showed that all CsSODs were upregulated under salt stress, with some exhibiting significant changes in expression. These findings all highlight the crucial role of CsSODs in the salt stress response and provide valuable insights for further breeding salt-tolerance varieties of C. sinense.

Species are disappearing worldwide, and changes in climate and land use are commonly assumed to be the most important causes. Organisms are counteracting the negative effects of environmental factors on their survival by evolving various defence strategies, which positively affect their fitness. Here, the question addressed is: can evolution shape these defence strategies so that they positively affect the fitness of an organism? This question is complex and depends on the taxa and environmental factors. Therefore, here, only a special case of this question is studied in deceptive species of orchids: reproductive success (RS, ratio of the number of fruits to the number of flowers produced by a plant during the whole season), a commonly used measure of fitness is used to develop a model describing how RS affects the number of flowers, n, of a plant. This model predicts that: (i) the resulting relationship between RS and n is a positively skewed parabola, (ii) the distribution of the numbers of individuals with a specific number (n) of flowers, NI(n), also resembles a parabola and is also positively skewed, and that (iii) the peak of the distribution of NI is to the left of the peak of RS. A large set of data is presented that supports these predictions. If the data set is small, the concave positively skewed parabolic RS–n dependence is obscured by other factors.

Pollination by sexual deception specifically attracts male insects, through the floral scent and particular morphological features of the flower that serve as visual and tactile stimuli. The unique bond between the Ophrys speculum orchid and the male Dasyscolia ciliata wasp primarily stems from a few distinctive semiochemicals that mimic the female wasp's sex pheromone, although the floral scent comprises a variety of compounds. An osmophore producing highly volatile compounds has been documented in four close relatives of O. speculum and is now being also investigated in this species. Given the existing debates regarding the structure of the labellum and stigmatic cavity in O. speculum, this study details their micromorphology. Additionally, comparisons of O. speculum flowers and female D. ciliata wasps under stereomicroscopy and scanning electron microscopy are conducted to seek new evidence of visual and tactile mimicry. The findings confirm that (i) an osmophore is present at the apical margin of the labellum in O. speculum flowers; (ii) the labellum features a distinct basal field homologous to those found in other Ophrys species; and (iii) the basal labellum region closely mimics the female wasp's thorax and wings. The implications of these novel floral features are discussed within an evolutionary context. [ABSTRACT FROM AUTHOR]