Terrestrial Orchid Research Articles

Pollinator diversity of the food-deceptive orchids in southern Italy.

The orchid family is renowned for its enormous diversity in pollination biology. Many orchid species use deception to attract pollinators, and the main strategy in terrestrial orchids is food deception. Food-deceptive orchids usually show a low number of pollinator visitations, making field observations of pollinators difficult. In this study visual census, pollinator capture and molecular analysis of pollinaria found on caught insects allowed us to obtain information on species composition of orchid pollinators. A total of 321 insects were caught; most specimens were hymenopterans (Apis mellifera, Bombus ruderatus and Eucera rufa) and coleopterans (Tropinota hirta and T. squalida). The identity of species to which pollinaria found on the insect's body belonged was confirmed by molecular analysis. Moreover, some individuals of Billaea lata (Tachinidae, Diptera) were captured and photographed with the pollinaria on their head. Two new and important results emerged clearly in this work: a dipteran, Billaea lata, pollinator of Anacamptis pyramidalis, and two beetles in the genus Tropinota are pollinators of Orchis italica. Our results confirm that generalized food-deceptive orchids of the genera Orchis and Anacamptis show weak pollinator specificity.

Clonal propagation of rare orchid species Paphiopedilum spp. (Orchidaceae) to save Indonesian biodiversity

Paphiopedilum spp. is one of the terrestrial orchids that is interesting as an ornamental plant. This orchid flower has a distinctive characteristic, namely its labellum resembles a sac, so it is sought after by ornamental flower collectors because of its uniqueness. This orchid is included in the Appendix I group according to CITES, namely a critical species that is threatened with extinction, so it needs to be conserved both in situ and ex situ. Ex situ conservation can be done by propagating orchids using in vitro culture techniques. The objective of this research is to carry out mass propagation of 3 species of Paphiopedilum spp orchids: P. supardii, P. primulinum, P. glaucophyllum through somatic embryogenesis and to characterize the existence of embryo gene RKD4 homolog in Paphiopedilum orchids. The method is to culture the nodes slices in dark conditions for 2 weeks, and then changed to photoperiod mode 16:8 hours (dark:light) on ½ MS media plus a combination of 2,4-D or NAA with TDZ. The somatic embryo were analyzed anatomically. This method is an improvement over previously reported methods for Paphiopedilum spp. due to its efficiency and reproducibility for conservation. We concluded that ½ MS media with a combination of NAA or 2,4D with TDZ were able to induce somatic embryogenesis. The result show that 3 mg L−1 NAA was the best PGRs for PLBs induction in P. supardii (50 %), 1 mg L−1 2,4-D + 0.5 mg L−1 TDZ was the best PGRs for callus embryogenic induction in P. primulinum (20 %), and 1 mg L−1 NAA was the best PGRs for PLBs induction in P. glaucophyllum (33 %).

Diversity of Orchid species in the Tilu Mountains Region of Indonesia and the Potential for Phytochemistry

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.

Colonization by orchid mycorrhizal fungi primes induced systemic resistance against necrotrophic pathogen.

Orchids and arbuscular mycorrhiza (AM) plants evolved independently and have different structures and fungal partners, but they both facilitate nutrient uptake. Orchid mycorrhiza (OM) supports orchid seed germination, but unlike AM, its role in disease resistance of mature plants is largely unknown. Here, we examined whether OM induces systemic disease resistance against a necrotrophic pathogen in a similar fashion to AM. We investigated the priming effect of mycorrhizal fungi inoculation on resistance of a terrestrial orchid, Bletilla striata, to soft rot caused by Dickeya fangzhongdai. We found that root colonization by a compatible OM fungus primed B. striata seedlings and induced systemic resistance against the infection. Transcriptome analysis showed that priming was mediated by the downregulation of jasmonate and ethylene pathways and that these pathways are upregulated once infection occurs. Comparison with the reported transcriptome of AM fungus-colonized rice leaves revealed similar mechanisms in B. striata and in rice. These findings highlight a novel aspect of commonality between OM and AM plants in terms of induced systemic resistance.

Nutritional, Phytochemical, and Functional Properties of Four Edible Orchid Species from Malawi.

Terrestrial orchid tubers are an important source of food in some parts of Africa and are traditionally included in the diets of most rural communities in Malawi. However, there is limited information on the nutritional and phytochemical content of the Malawian orchids to substantiate their traditional use. The present study evaluates the nutritional and phytochemical variation of four orchid species: Disa zombica, Satyrium buchananii, Satyrium carsonii, and Satyrium trinerve, collected from the same ecological zone of Malawi. The proximate content, minerals, phytochemicals, and functional properties were analysed using official procedures. Protein ranged from 2.19% to 4.65%, whereas carbohydrate ranged from 65.24% to 80.22%, with S. carsonii and S. trinerve registering the highest protein and carbohydrate contents, respectively. Iron and potassium were highest in D. zombica, while sodium and calcium were highest in S. buchananii. The total phenolics ranged from 228.56 to 500.00 mg GAE/100 g, with D. zombica registering the highest. The water absorption capacity ranged from 4.10 to 10.88 g/g. Despite variable levels, the study provides evidence that orchid species contain essential nutrients and phytochemicals important for human nutrition and health. Furthermore, the functional properties can be utilised in the development of food products, such as baked products.

Settling moth pollination of a rare orchid in the Habenaria clade revealed with close-focusing camera traps.

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.

Variation in root functional traits of Neotropical epiphytic and terrestrial orchids along an elevational gradient

Abstract Assessing variation in root functional traits may offer novel insights into plant adaptations to changing environmental conditions. However, such studies, particularly on epiphytic species in tropical ecosystems, are still limited. Previous research has suggested that precipitation has a major impact on epiphyte survival and thus can be considered a candidate driver of epiphytic root trait variation, though compelling evidence is lacking. In this study, we investigated variation in 19 root functional traits in 43 epiphytic (36 species) and 14 terrestrial (7 species) orchids along an elevational gradient in Colombia and examined whether this variation is associated with differences in abiotic conditions. Contrary to previous studies, our findings did not associate trait variation with precipitation but revealed strong correlations with solar radiation, temperature, and water vapour pressure. The variation was particularly pronounced in traits related to the velamen radicum. Epiphytic and terrestrial orchids showed similar responses despite their different growth habits. Overall, these patterns suggest that higher sunlight and temperature conditions lead both orchid types to allocate more resources to root structures that mitigate abiotic stress, and highlight the role of other environmental factors in driving root trait variability.

Effect of zeatin and casein hydrolysate on in vitro asymbiotic germination of immature seeds of Vanilla planifolia Jacks ex Andrews (Orchidaceae)

The germination of Vanilla planifolia seeds under natural environmental conditions is very low (0.1 %) because of specific mycorrhizal requirements. Therefore, the species is typically propagated spending vegetative using stem cuttings. Thus, all cultivated plants are genetically identical and susceptible to multiple abiotic and biotic stressors. Artificial propagation from seeds is difficult for most terrestrial orchids native to temperate regions, and V. planifolia is no exception. As propagation from the seeds of this species has low success rates, in this study, an effective reproducible protocol for the in vitro asymbiotic germination of Vanilla planifolia seeds was established. For this purpose, the effects of three asymbiotic culture media on seed germination and seedling development of Vanilla planifolia [Murashige and Skoog (MS), Vacin and Went (VW), Knudson ‘C’ (KC)] were tested, two zeatin concentrations (Z = 0.25 and 0.50 mg L−1), two concentrations of casein hydrolysate (CH=50 and 500 mg L−1), and two combinations of these (Z = 0.25 mg L−1 + CH=250 mg L−1) and (Z = 0.50 mg L−1 + CH=500 mg L−1). The highest germination rate (74.5%) was recorded for the treatment with MS salts at a quarter strength supplemented with 500 mg L−1 of CH. All the seeds that germinated under this treatment showed high survival and vigorous seedling growth. In contrast, in the treatment with MS salts at a quarter strength supplemented with combination of CH and Z (CH=500 mg L−1 + Z = 0.50 mg L−1) resulted in the production of calluses (53 %).

Analysis of the Fungal Community Composition in Endemic Orchids with Terrestrial Habitat in Subtropical Regions.

Habenaria and Liparis are well-known orchid genera that grow in terrestrial habitats in the tropics, subtropics or temperate zones. Three species have been found in subtropical regions of China, inhabiting terrestrial to epiphytic habitats. This study focuses on three species, H. dentata (distributed in Asia), H. yachangensis, and L. gigantea. For H. yachangensis and L. gigantea, there is no information about the mycorrhizal community in these species. This study aims to conduct the fungal community screening of Chinese ground orchids from subtropical regions. We performed a comparative analysis of the fungal community among H. dentata, H. yachangensis, and L. gigantea, determining their ITS regions using NGS paired-end sequences. The results clarified the diversity and the predominance of fungal genera. Ascomycota was abundant compared to Basidiomycota or other fungi groups in all communities, with a high dominance in all populations, especially for L. gigantea. At different root spatial locations, the fungal community diversity and richness were higher in the soil than in the rhizosphere or inner root. However, the results suggest that L. gigantea has a different fungal community compared to Habenaria species. In this order, the subtropical terrestrial orchids have a different fungal network compared to the northern terrestrial orchids. Also, there is a high probability of co-existence and co-evolution of endophytic fungi in these terrestrial orchids, indicating the potential role of host plants in selecting an endophytic fungal community. Furthermore, our results highlight the need to elucidate the microbe interactions of these unique orchids for long-term purposes, such as isolating indigenous fungi for suitable inoculants for further orchid propagation, restoration, and conservation.

Pollination by multiple species of nectar foraging Hymenoptera in Prasophyllum innubum, a critically endangered orchid of the Australian Alps

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.

Update on the terrestrial orchid flora of the Tacana volcano and close area, Chiapas, Mexico

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

Photosynthate transfer from an autotrophic orchid to conspecific heterotrophic protocorms through a common mycorrhizal network.

The minute 'dust seeds' of some terrestrial orchids preferentially germinate and develop as mycoheterotrophic protocorms near conspecific adult plants. Here we test the hypothesis that mycorrhizal mycelial connections provide a direct pathway for transfer of recent photosynthate from conspecific green orchids to achlorophyllous protocorms. Mycelial networks of Ceratobasidium cornigerum connecting green Dactylorhiza fuchsii plants with developing achlorophyllous protocorms of the same species were established on oatmeal or water agar before the shoots of green plants were exposed to 14CO2. After incubation for 48 h, the pattern of distribution of fixed carbon was visualised in intact entire autotrophic/protocorm systems using digital autoradiography and quantified in protocorms by liquid scintillation counting. Both methods of analysis revealed accumulation of 14C above background levels in protocorms, confirming that autotrophic plants supply carbon to juveniles via common mycorrhizal networks. Despite some accumulation of plant-fixed carbon in the fungal mycelium grown on oatmeal agar, a greater amount of carbon was transferred to protocorms growing on water agar, indicating that the polarity of transfer may be influenced by sink strength. We suggest this transfer pathway may contribute significantly to the pattern and processes determining localised orchid establishment in nature, and that 'parental nurture' via common mycelial networks may be involved in these processes.

ASYMBIOTIC SEED GERMINATION OF AN ANTICANCEROUS TERRESTRIAL ORCHID Eulophia nuda Lindl. AND ITS ADULTERANT Geodorum densiflorum (Lam) Schltr.

Eulophia nuda Lindl. corms are used to cure cancer and is overexploited by the traditional medicine practitioners and medicinal plant traders. The corms of Geodorum densiflorum look morphologically similar to the corms of Eulophia nuda, hence it is used as an adulterant to the corms of Eulophia nuda, consequetly, the population of G. densiflorum is also facing the exploitation pressure. In present study, asymbiotic seed germination of both the terrestrial orchids was achieved using six media like Vacin and Went (WV) medium, Malmgren modified (MM) terrestrial orchid medium, modified Kundson C medium, ½ MS medium, Lindemann medium (LM) and BM1 medium along with three photoperiods (0/24, 16/8, and 24/0 h L/D). Eulophia nuda showed highest asymbiotic seed germination on MM medium (80.55 %) and the best light treatment was 0/24 h L/D. The highest asymbiotic seed germination of G densiflorum was on VW (84.07%), LM (83.29%) and BM 1(81.02%) and the best light treatment was 24/0 h L/D.

Epipogium Borkh. (Orchidaceae): a new generic record for Andhra Pradesh, India

Epipogium roseum (D.Don) Lindl., an ephemeral, achlorophyllous, mycoheterotrophic, terrestrial orchid is reported as a new state record after its first collection from the Paderu hills of Andhra Pradesh, India. Detailed descriptions, information on the type, ecology, photographs, and details of voucher specimens are provided.

Orchidinae-205: A new genome-wide custom bait set for studying the evolution, systematics, and trade of terrestrial orchids.

Terrestrial orchids are a group of genetically understudied, yet culturally and economically important plants. The Orchidinae tribe contains many species that produce edible tubers that are used for the production of traditional delicacies collectively called 'salep'. Overexploitation of wild orchids in the Eastern Mediterranean and Western Asia threatens to drive many of these species to extinction, but cost-effective tools for monitoring their trade are currently lacking. Here we present a custom bait kit for target enrichment and sequencing of 205 novel genetic markers that are tailored to phylogenomic applications in Orchidinae s.l. A subset of 31 markers capture genes putatively involved in the production of glucomannan, a water-soluble polysaccharide that gives salep its distinctive properties. We tested the kit on 73 taxa native to the area, demonstrating universally high locus recovery irrespective of species identity, that exceeds the total sequence length obtained with alternative kits currently available. Phylogenetic inference with concatenation and coalescent approaches was robust and showed high levels of support for most clades, including some which were previously unresolved. Resolution for hybridizing and recently radiated lineages remains difficult, but could be further improved by analysing multiple haplotypes and the non-exonic sequences captured by our kit, with the promise to shed new light on the evolution of enigmatic taxa with a complex speciation history. Offering a step-up from traditional barcoding and universal markers, the genome-wide custom loci targeted by Orchidinae-205 are a valuable new resource to study the evolution, systematics and trade of terrestrial orchids.

The impacts of inter- and intra-seasonal burns on the terrestrial orchid Pterostylis curta

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.

Phytochemical Analysis of the Medicinal Plant Terrestrial Orchid (Orchis Simia) in the Flowering Stage

Phytochemical Analysis of the Medicinal Plant Terrestrial Orchid (Orchis Simia) in the Flowering Stage

Floristic Diversity and Green-Tree Retention in Intensively Managed Temperate Forests: A Case Study in Puebla, Mexico

Clearcutting has tended to simplify forest structure and species composition, with potential negative consequences for biodiversity. Retention forestry emerged as an alternative to minimize this concern in intensively managed forests. In central Mexico, this approach was first implemented a decade ago in temperate forests, but an examination of its effects on floristic diversity and composition is non-existent. We evaluated and compared richness, diversity, and floristic composition among harvested, retention, and conserved areas in a conifer-dominated forest of central Mexico, with various parametric and non-parametric analyses. Species’ ecological and structural importance was also evaluated. We recorded 138 species, 95 genera, and 44 families of plants. Harvested areas listed the most species (99) with herb dominance, tree homogeneity, and the highest number of exotics. Retention and conserved areas’ floristic composition was similar, with the presence of epiphytes and terrestrial orchids, considered indicators of conservation. The retention areas recorded rare and endangered species, tree heterogeneity, and juveniles of structural species of temperate forests. Conserved areas showed a greater number of structural mature elements and exclusive species, though there was a smaller species number (75). We demonstrated that retention forestry is achieving its goal by maintaining the structural elements, habitats, and plant diversity of the temperate forests analyzed.

Vascular Plants of Bastar, Madhya Pradesh

The Bastar area comes under Bastar district of the Madhya Pradesh and lies south of Raipur between 19°0'-21°0'N and 81°0'-82°0'E. The major portion of this area has more or less remained botanically unexplored so far and three exploration trips were conducted in the years 1958, 1959 and 1961, and a total number of 481 species representing 336 genera and 112 families were collected.The vegetation at the foot and lower slopes of the hills is of the mixed deciduous type. The undergrowth in these forests is rather sparse. Evergreen forests occur in Kanger Valley, Dharba, Kutumsar and along the upper slopes of Bailadila. The hill-tops, particularly at Dharba and Narayanpur, are rich in grasses and herbs and amidst these terrestrial orchids are also noticed. Since there are a number of tanks, at the foot of these hills and in the plains which are wet and marshy during the rainy season, interesting aquatic and marshy plants are met with.

Flowering Plants and Ferns of North Garhwal, Uttar Pradesh, India

The paper gives an account of the recent collection of flowering plants and ferns from the Garhwal Himalayas, made by the author during the years 1957 to 1959 in which nearly 1500 gatherings were made which on study yielded 738 species. The area covered by this study lies between 30° and 31° N., and 79° and 80° E., and includes the Alaknanda, Arwa, Bhyundar, Khiraun, Mandakini and Nandakini river valleys and their neighbouring glacial beds, mountain slopes and meadows ranging in altitude between 2000 and 4500 metres. Cypripedium elegans Reichb. f., a rare terrestrial orchid was collected for the first time in Western Himalayas.