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Study site and study species illustration (a) Pu’er original habitat on the right side of the picture in May 2014, (b) P. spicerianum flowering on the steep hill in October 2013, (c) XTBG collections, (d) Pu’er habitat on the left side of the picture in May 2014.
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Paphiopedilum spicerianum (Rchb. f) Pfitzer has only one wild population with 38 individuals in Pu’er, southern China, and has been closely monitored under the Plant Species with Extremely Small Population project launched in 2005. Immediate conservation actions, including ex situ conservation, pollination observations, and studies of asymbiotic ge...
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Context 1
... with a hottest month of 25.6 °C and coldest of 17.2 °C, average of at 22.2 °C and 1161.8 mm average annual rainfall (Yan and Zhang Licai, 2008). The translocated individuals were planted into separated pots containing half mixed coconut husks and bark chips mix, and half original habitat soil with regular fertilization and irrigation weekly (Fig. ...Similar publications
PREMISE OF THE STUDY: Microsatellite markers were developed for New Zealand species of Corybas (Orchidaceae) to investigate population genetics and species delimitation.
METHODS AND RESULTS: From sequencing a total genomic DNA library (using Illumina MiSeq), we developed 22 microsatellite markers for C. obscurus. The di-and trinucleotide repeat loc...
Orchids are known for their vast diversity and dependency on mycorrhizal fungi. Under in situ conditions, the biotic and abiotic factors determining the composition and distribution of orchid mycorrhizal fungi (OMF) communities remain largely unexplored. Therefore in situ experiments are needed to better understand the interactions between orchids...
Citations
... The diversity of orchid mycorrhizal communities in both terrestrial and epiphytic orchids can also vary across soil characteristics, including nutrient content (Han et al. 2016;Mujica et al. 2016), texture (Tran et al. 2021), environmental heterogeneity (Duffy et al. 2019), and altitudinal gradients (Ren et al. 2021;Liang et al. 2022). For example, Duffy et al. (2019) documented high abundance of Sebacinaceae, Serendipitaceae, and Tulasnellaceae OTUs in roots of a widely distributed terrestrial orchid, Spiranthes spiralis, at the lower latitude of its habitat with lower precipitation and lower soil nitrogen in comparison to its habitats at higher latitudes. ...
... In general, the failure to recover some pOMF taxa might happen as a result of the PCR primer bias. However, this bias can be ruled out in the current study as the primers we utilized were optimized to characterize pOMF communities including Sebacinaceae OTUs in many temperate and tropical orchids Han et al. 2016;Jacquemyn et al. 2017;Wang et al. 2022), and have outperformed other primer pairs ). Therefore, our results truly reflect the overall pOMF diversity in Vanilla species. ...
Despite being the second largest family of flowering plants, orchids represent community structure variation in plant-microbial associations, contributes to niche partitioning in metacommunity assemblages. Yet, mycorrhizal communities and interactions remain unknown for orchids that are highly specialized or even obligated in their associations with their mycorrhizal partners. In this study, we sought to compare orchid mycorrhizal fungal (OMF) communities of three co-occurring hemiepiphytic Vanilla species (V. hartii, V. pompona, and V. trigonocarpa) in tropical forests of Costa Rica by addressing the identity of their OMF communities across species, root types, and populations, using high-throughput sequencing. Sequencing the nuclear ribosomal internal transcribed spacer (nrITS) yielded 299 fungal Operational Taxonomic Units (OTUs) from 193 root samples. We showed distinct segregation in the putative OMF (pOMF) communities of the three coexisting Vanilla hosts. We also found that mycorrhizal communities associated with the rare V. hartii varied among populations. Furthermore, we identified Tulasnellaceae and Ceratobasidiaceae as dominant pOMF families in terrestrial roots of the three Vanilla species. In contrast, the epiphytic roots were mainly dominated by OTUs belonging to the Atractiellales and Serendipitaceae. Furthermore, the pOMF communities differed significantly across populations of the widespread V. trigonocarpa and showed patterns of distance decay in similarity. This is the first report of different pOMF communities detected in roots of wild co-occurring Vanilla species using high-throughput sequencing, which provides evidence that three coexisting Vanilla species and their root types exhibited pOMF niche partitioning, and that the rare and widespread Vanilla hosts displayed diverse mycorrhizal preferences.
... A comparative assessment of wild sites hosting orchids with potential receiver sites in terms of nutrient levels and fungal community composition is critical for reintroduction, the reinforcement of populations, and assisted colonisation. Such research will help to identify nearly optimal sites, as previous studies have demonstrated the impact of seasonality on orchid mycorrhizal fungal community compositions [42,43]. ...
The yellow early marsh orchid (Dactylorhiza incarnata ssp. ochroleuca) is a critically endangered terrestrial orchid in Britain. Previous attempts to translocate symbiotic seedlings to a site near the last remaining wild site demonstrated some success, with a 10% survival rate despite adverse weather conditions over a two-year period. However, to facilitate future reintroduction efforts or conservation translocations, a more comprehensive understanding of the fungal microbiome and abiotic soil characteristics at the final remaining wild site is required. Obtaining comprehensive information on both the fungal community and soil nutrient composition from wild sites has significant benefits and may prove critical for the success of future conservation translocations involving threatened orchids. This preliminary study, conducted at the last remaining wild site, revealed a significant correlation between the relative abundance of the orchid mycorrhizal fungal order Cantharellales and the concentrations of nitrate and phosphate in the soil. Another orchid mycorrhizal fungal group, Sebacinales, was found to be distributed extensively throughout the site. The composition of fungal communities across the entire site, orchid-hosting and non-orchid-hosting soils is discussed in relation to reinforcing the current population and preventing the extinction of this orchid.
... There are about 27 native species found in China, most of which are distributed in Yunnan or Guangxi province [3]. Over-collection and loss of suitable habitats have led to the wild population of Paphiopedilum being under the threat of extinction [4]. All species in Paphiopedilum are listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) [5]. ...
Ex situ conservation, an important way to increase the survival and sustainability of endangered species, is widely used in the conservation of endangered orchids. However, long-term ex situ conservation might affect the dominant group of orchid symbiotic fungi, which are crucial for orchid growth and reintroduction. This study investigated the culturable Tulasnella spp. associated with Paphiopedilum orchids after long-term greenhouse cultivation, and identified germination-enhancing isolates. A total of 44 Tulasnella isolates were obtained from the roots of 14 Paphiopedilum spp., and 29 of them were selected for phylogenetic analysis. They clustered mainly with Tulasnella deliquescens, Tulasnella calospora, Tulasnella bifrons, and Tulasnella irregularis, but included two potential new groups. Compared with published uncultured data, most of the isolates were grouped together with the reported types, and the dominant Tulasnella associated with P. armeniacum and P. micranthum could still be isolated after ten years of cultivation, most of which were the first isolation. In vitro symbiotic germination showed that certain root isolates could promote seed germination (e.g., parm152 isolated from P. armeniacum, Php12 from P. hirsutissimum, and prhi68 from P. rhizomatosum). These data indicated that the dominant Tulasnella types colonizing the roots of cultivated Paphiopedilum are stable over time, and germination-enhancing fungi colonizing the roots would benefit for seed reproduction after population reintroduction into the wild.
... It is conceivable that similar to OMF (Han et al., 2016;Voyron et al., 2017;Egidi et al., 2018;Kaur et al., 2019), orchid associated endophytic bacteria represent bacterial taxa that prefer to reside within-and transmit through-plant roots or tubers and consequently are difficult to detect in habitat soil. Another possibility is that OMF is the preferred niche (extra-or endo-hyphal) of the dominant bacterial endophytes of the host orchids. ...
Premise of the study:
Besides the beneficial plant-fungus symbiosis in mycorrhizal plants, bacteria also enhance plant fitness via tripartite interactions. While bacterial associations are presumably just as important for the obligate mycorrhizal family Orchidaceae, little is known about orchid associating bacteria (OAB).
Methods:
We examined the OAB communities of two congeneric terrestrial orchids, Platanthera cooperi and Platanthera praeclara, that represent widely disparate North American ecosystems. We tested whether they recruit distinct OAB communities, and whether variability in OAB communities can be linked to phenology, population size, or habitat soil. Genomic DNAs from roots of seedling, vegetative, and reproductive plants and from soil were subjected to Illumina sequencing of V4 and V5 regions of the 16S rRNA gene.
Key results:
We obtained 809 OAB Zero-radius Operational Taxonomic Units (ZOTUs). Despite an overlap of 209 ZOTUs that accounted for >75% relative abundances of their respective OAB communities, the overall community structures of the two orchids were distinct. Within each orchid, distinctions were detected in the OAB communities of large and small populations and the three phenological stages. The OAB ZOTUs were either absent or present with low abundances in soil associated with both orchids.
Conclusions:
The two orchids exhibited preferential recruitment of known growth-promoting OAB communities from soil. Their OAB communities also showed considerable overlap despite the large environmental and geographical separation of the two host taxa. Our results lend further support to the emerging evidence that not only the fungi, but root-associated bacteria also have functional importance for plant ecology. This article is protected by copyright. All rights reserved.
... Studies based on variation of OMF across seasons, years and ontogenetic stages (Bidartondo and Read 2008;Kohout et al. 2013;Ercole et al. 2015;Kaur et al. 2018Kaur et al. , 2019Ventre Lespiaucq et al. 2021) show a range of OMF turnover from high fidelity to total replacement. For example, seedling, vegetative, and reproductive stages of the rare terrestrial orchid Platanthera praeclara persistently associated with a narrow phylogenetic clade of Ceratobasidiaceae OTUs, with few others (Kaur et al. 2019), while a complete OMF turnover was reported in plant roots of the terrestrial Paphiopedilum spicerianum between wet and dry seasons in a seasonally flooded river bank in Yunnan, China (Han et al. 2016). Intermediate states between high fidelity and total replacement of OMF across time have been reported. ...
Mycorrhizal symbiosis has been related to the coexistence and community assembly of coexisting orchids in few studies despite their obligate dependence on mycorrhizal partners to establish and survive. In hyper-diverse environments like tropical rain forests, coexistence of epiphytic orchids may be facilitated through mycorrhizal fungal specialization (i.e., sets of unique and dominant mycorrhizal fungi associated with a particular host species). However, information on the role of orchid mycorrhizal fungi (OMF) in niche differentiation and coexistence of epiphytic orchids is still scarce. In this study, we sought to identify the variation in fungal preferences of four co-occurring epiphytic orchids in a tropical rainforest in Costa Rica by addressing the identity and composition of their endophytic fungal and OMF communities across species and life stages. We show that the endophytic fungal communities are formed mainly of previously recognized OMF taxa, and that the four coexisting orchid species have both a set of shared mycorrhizal fungi and a group of fungi unique to an orchid species. We also found that adult plants keep the OMF of the juvenile stage while adding new mycobionts over time. This study provides evidence for the utilization of specific OMF that may be involved in niche segregation, and for an aggregation mechanism where adult orchids keep initial fungal mycobionts of the juvenile stage while adding others.
... All of the samples were collected in a way that caused as little damage to the habitat as possible and without putting C. sieboldii's survival at risk [70]. Samples of roots, rhizosphere soil, and rhizoplane soil were collected from the same spot in Jing County, Xuancheng City, Anhui Province, China, in April 2019, September 2019, September 2020, and April 2021. ...
Background:
Endophytic fungi play a critical ecological role in the growth and development of orchids, but little is known about the spatial and temporal dynamics of fungal diversity or the ecological functions of fungi during orchid growth and reproduction. Calanthe sieboldii Decne. is listed in the Chinese National Key Protected Wild Plants as a class I protected wild plant. To understand the community characteristics of root and soil fungi of the orchid during its reproductive seasons, we investigated the community composition, spatial and temporal dynamics, and functional characteristics of the orchid microhabitat fungi by using diversity and ecological functional analyses.
Results:
We discovered that there were three, seven, and four dominant fungal families in the orchid's roots, rhizoplane soil, and rhizosphere soil, respectively. Tulasnellaceae, Aspergillaceae, and Tricholomataceae were the dominant fungi in this endangered orchid's microhabitats. The closer the fungal community was to the orchid, the more stable and the less likely the community composition to change significantly over time. The fungal communities of this orchid's roots and rhizoplane soil varied seasonally, while those of the rhizosphere soil varied interannually. Saprophytic fungi were the most abundant in the orchid's fungal community, and the closer the distance to the orchid, the more symbiotic fungi were present.
Conclusions:
The fungi in different parts of the root microhabitat of C. sieboldii showed different spatiotemporal dynamic patterns. The fungal community near the orchid roots was relatively stable and displayed seasonal variation, while the community further away from the roots showed greater variation. In addition, compared with the soil fungi, the dominant endophytic fungi were more stable, and these may be key fungi influencing orchid growth and development. Our study on the spatiotemporal dynamics and functions of fungi provides a basis for the comprehensive understanding and utilization of orchid endophytic fungi.
... Such community differences among sites have also been recorded in terrestrial orchids (Jacquemyn et al., 2012;Kohout et al., 2013;Oja et al., 2015). There is some evidence that soil chemical characteristics such as phosphorus, zinc, and organic matter (Kaur et al., 2021) and nitrogen, phosphorus, and water content (Han et al., 2016), impact OMF communities in orchid roots and soils. These differences in substrate chemical and physical characteristics may vary among sites, resulting in corresponding OMF community differences. ...
Dendrobium officinale (Orchidaceae) is an endangered epiphytic orchid that has been well studied as a medicinal plant. Although previous studies have shown that various fungal isolates promote D. officinale seed germination and seedling development in vitro, mycorrhizal associations among its wild populations remain poorly understood. In this study, we identified mycorrhizal fungi associated with D. officinale (36 individuals from six sites) using Sanger sequencing and compared fungal communities among sites and habitats (lithophytic vs. epiphytic individuals). Among the obtained sequences, 76 belonged to orchid mycorrhizal fungi (OMF), among which Tulasnellaceae accounted for 45.8% and Serendipitaceae for 28.1%. The Serendipitaceae operational taxonomic unit (OTU) SE1 was the most dominant partner, accounting for 27.1% of all detected fungal sequences, followed by a Tulasnellaceae OTU, TU27, which accounted for 15.6%. The relative frequencies of Serendipitaceae and Tulasnellaceae differed greatly between lithophytic and epiphytic individuals. Serendipitaceae accounted for 47.3% of the OMF sequences among lithophytes, and Tulasnellaceae for 95.2% among epiphytes. Mycorrhizal community composition also varied among sites. We further conducted in vitro symbiotic culture from seeds with six fungal isolates. Two Serendipitaceae and two Tulasnellaceae isolates, including SE1 and TU27, significantly promoted seed germination and seedling development. These results indicate that D. officinale is mainly associated with Tulasnellaceae and Serendipitaceae as its main fungal partners, which strongly induced seed germination and seedling development in vitro, suggesting their association with D. officinale through its life cycle.
... The results show that most of the mycorrhizal fungi found in roots are also widely distributed in soil . At the same time, other studies found that the mycorrhizal fungi communities in orchid roots and rhizosphere soils are significantly different (Liu et al., 2015;Han et al., 2016). The second generation sequencing technology was used to analyze fungal communities and mycorrhizal fungi composition in roots, rhizosphere soil and rhizosphere soil of nine orchids belonging to minimal populations in Liaoning Province, China. ...
Mycorrhizal fungi plays important roles in the seed germination and subsequent growth of orchids. The research of fungi in orchid roots, especially dominant mycorrhizal fungi is critical for orchids protection. In this study, the fungal community and composition of mycorrhizal fungi in roots, rhizomes and rhizosphere soil of Bulbophyllum tianguii grown in three terrestrial environments were analyzed by the second generation sequencing technology. The results of OTU clustering and α and β diversity analysis showed that there were significant differences in fungal communities in roots, rhizomes and rhizosphere soil of B. tianguii. The total number of OTUs in rhizomes was much less than that in roots and rhizosphere soil. The number of OTUs in rhizosphere soil and the diversity of mycorrhizal fungi were the highest. Meanwhile, the species and abundance of mycorrhizal fungi in roots and rhizomes of B. tianguii were different from those in rhizosphere soil. For different elevations, compared with B. tianguii that grow in middle of Tiankeng and top of Tiankeng, the OTUs number of B. tianguii in orchid garden is richest, and the diversity of mycorrhizal fungi in orchid garden was significantly higher than other locations. Among the three different habitats of B. tianguii, the number of OTUs in humus soil and stone habitats was notably higher than tree habitats, and the diversity of mycorrhizal fungi in humus soil was the highest. The analysis of mycorrhizal fungi in different habitats and altitudes of B. tianguii showed that Sebacina and Exophiala were the dominant mycorrhizal fungi in B. tianguii. The results of species annotation, phylogenetic tree and co-occurrence network analysis showed the dominant mycorrhizal fungi of B. tianguii mainly included Sebacina, Cladosporium, Exophiala, Fusarium. This study reveals the symbiotic relationship between Sebacina, Exophiala, Cladosporium and the B. Tianguii. It will provide a theoretical basis for the protection and biological function study of B. Tianguii.
... To describe the basidiomycetous mycorrhizal community in orchids, effective broad-spectrum basidiomycete primer pairs were used. These included ITS1-OF/ITS4-OF [58], ITS1F/ITS4 [25], ITS1/ITS4-Tul [58], and ITS3/ITS4-OF [59]. This specific amplification of basidiomycetous fungi usually could not reflect the real fungal community structure in orchids. ...
Orchids exhibit varying specificities to fungi in different microbial environments. This pilot study investigated the preference of fungal recruitment during symbiotic germination of Epidendrum radicans Pav. ex Lindl. Two different orchid substrates were used for ex situ seed baiting: pine bark and rotten oak leaf, with Basidiomycota and Ascomycota as the respective dominant groups. Both substrates promoted seed germination, with a higher protocorm formation rate on pine bark (65.75%). High-throughput sequencing characterized the fungal communities of germinated protocorms. Basidiomycota was the dominant group in protocorms that symbiotically germinated on both substrates. The family-level community structures of endophytic fungi in protocorms that symbiotically germinated on both substrates were close to those of protocorms that germinated in vitro on MS1 medium. For protocorms, the dominant fungal groups recruited from substrates differed at the genus level; from pine bark, they were genera belonging to unclassified Sebacinales (41.34%), Thanatephorus (14.48%) and Fusarium (7.35%), while, from rotten oak leaf, they were Rhizoctonia (49.46%), Clitopilus (34.61%), and Oliveonia (7.96%). Four fungal isolates were successfully obtained and identified as belonging to the family Tulasnellaceae, genera Ceratobasidium and Peniophora, which could promote seed germination to the seedling stage. The data indicate that endophytic fungi for E. radicans germination on two different substrates are affected at the genus level by the substrate, with a degree of specificity at the family level.
... In addition, Tulasnellaceae fungi of P. armeniacum at different growth stages were analyzed to gain insights into their mycorrhizal features. Most studies on the root biomes of orchids have mainly focused on specific stages of growth, with little attention directed at trends during the development of cultivated orchids [5,6,[42][43][44][45]. ...
Paphiopedilum armeniacum S. C. Chen et F. Y. Liu is an endangered lady’s slipper orchid species with high horticultural value. As observed for other orchids, mycorrhizal fungi and endophytic bacteria play important roles in the growth and development of P. armeniacum. In the present study, the community structure dynamics across three growth and development stages of cultivated P. armeniacum were investigated. The potential interactions between Tulasnellaceae fungi and core bacterial genera on one hand and the stability of the presumed mycorrhizal fungi communities on the other were analyzed in three growth stages of P. armeniacum to enhance our understanding of endophytic microbial community structure dynamics in the roots at different development stages. Based on sequencing, 3 and 16 phyla and 59 and 269 genera were identified in the fungal and bacterial communities, respectively. The predominant fungi and bacteria were Basidiomycota (62.90%) and Proteobacteria (43.98%), which exhibited changes in abundance and diversity depending on the growth stage of P. armeniacum. Assessment of the entire microbial communities from different growth stages showed that the seedling stage had the highest richness and diversity. The microbial communities recruited by P. armeniacum at the seedling stage were different from those recruited at the vegetative and reproductive growth stages, and the microbial communities recruited in the latter two stages overlapped. Tulasnellaceae were the only dominant fungal symbionts during P. armeniacum growth. Brevibacillus, Mycobacterium, and Sphingomonas, the three core genera, showed significant interactions with the main OTUs of Tulasnellaceae. Putative mycorrhizal fungi in P. armeniacum were relatively stable across different growth environments, and the core mycorrhizal fungi were uncultured Tulasnellaceae (OTU1). This could facilitate the ex situ conservation and commercial development of the endangered orchid.
