Ornamental Orchid Research Articles

In vitro propagation of Vanda orchid: a review

Vanda for the past decade has been the primadonna of ornamental orchids in the south and southeast Asia, along with Phalaenopsis and Dendrobium. Along with the increase in demand for Vanda, this genus has faced several threats from illegal collection to habitat loss. Mass propagation through in vitro culture is a promising strategy to make ensure sustainable business in horticulture, as well as for conservation purposes. This review provides an overview and synthesizes of various Vanda in vitro culture literature. We showed the researchers' preferences on several aspects for growing Vanda, including species, basal medium, plant growth regulators, explant, and culture conditions. The most commonly used as explants are seeds or protocorms, growing on Murashige & Skoog or Vacin & Went medium. This medium can be added banana homogenate to increase its nutritional value. Vanda seedlings can be incubated at 25 ± 1-3oC, with a lighting intensity of 50 μmol m-2 s-1 at 12/16 h PP. Choosing a medium that is cheaper but still rich in nutrients and its additives especially during the subculture phase; selection of explants that are responsive and minimizing the possibility of contamination; as well as seeing the target market in particular, can make Vanda's propagation efforts more effective, efficient, and profitable.

Strategy For Development of Orchid Ornamental Plant (Case Study of UPTD BBIH, Amoito Village, Ranomeeto District, South Konawe Regency)

This study aims to determine the strategy for developing ornamental orchids in UPTD BBIH, Amoito Village, Ranomeeto District, South Konawe Regency. This research is a case study on ornamental orchid plants determined on purpose (purposive sampling). Data analysis used the SWOT Analysis to determine the criteria and prospect alternatives that are the most priority for ornamental orchid plants. Based on the results of the identification of internal and external factors that determine the prospects for the development of ornamental orchids at UPTD BBIH, Amoito Village, Ranomeeto District, Konawe Selatan Regency, internal factors were found, namely the absence of technical guidance for workers, lack of service facilitation between product messages, using the availability of business capital and utilizing bonus purchase of ornamental plants orchids. While external factors are the lack of labour recruitment, the existence of a marketing network, using online media as promotion, and developing product creativity through exhibitions.

TISSUE CULTURE MULTIPLICATION OF Paphiopedilum insigne DEPENDING ON THE MEDIUM TYPE, GROWTH REGULATORS AND NATURAL SUPPLEMENTS

Paphiopedilum is an ornamental orchid used mainly for interior decoration. As the division of plants is uneconomical, a fast method of propagation is needed. The aim of this study was to evaluate the influence of medium type (MS or VW), growth regulators, i.e. BA, KIN, TDZ used separately or in combinations and natural additives, i.e. coconut water, banana pulp, casein hydrolysate, on Paphiopedilum insigne plantlets grown in vitro. It was found out that BA in concentration of 0.5 mg·dm–3 allowed to obtain the highest multiplication rate (2.92), however the use of KIN in concentration of 1 mg·dm–3 resulted in formation of bigger and higher quality plantlets, It is possible to replace cytokinins with other biologically active substance, such as banana pulp. The 1/2 MS medium might be used for Paphiopedilum insigne tissue culture, as there was no difference in terms of multiplication rate and the obtained plantlets were of better quality, especially that it is cheaper and easier to prepare.

Review: Factors affecting mass propagation of Vanda orchid in vitro

Abstract. Setiaji A, Annisa RRR, Santoso AD, Kinasih A, Riyadi ADR. 2021. Review: Factors affecting mass propagation of Vanda orchid in vitro. Cell Biol Dev 5: 51-62. For the past decade, Vanda has been the primadonna of ornamental orchids in the south and southeast Asia, along with Phalaenopsis and Dendrobium. Along with the increase in demand for Vanda, this genus has faced several threats, from illegal collection to habitat loss. Therefore, mass propagation through in vitro culture is a promising strategy to ensure sustainable business in horticulture and conservation. This review provides an overview and synthesizes various Vanda in vitro culture literature. We showed the researchers' preferences on several aspects for growing Vanda, including species, basal medium, plant growth regulators, explant, and culture conditions. The most commonly used as explants are seeds or protocorms, growing on Murashige & Skoog or Vacin & Went medium. This medium can be added banana homogenate to increase its nutritional value. Vanda seedlings can be incubated at 25 ± 1-3oC, with a lighting intensity of 50 ?mol m-2 s-1 at 12/16 h PP. Choosing a medium that is cheaper but still rich in nutrients and its additives, especially during the subculture phase; selecting explants that are responsive and minimizing the possibility of contamination; as well as seeing the target market in particular, can make Vanda's propagation efforts more effective, efficient, and profitable.

Pollination related temporal sequences of reproductive development and tracing the path of pollen tubes in Cymbidium pendulum (Roxb.) Sw., an ornamental orchid

Orchids, known for their exquisite beauty, are highly priced as cut flowers and potted plants at national and International market. More than I lac manmade hybrids are produced every year at intra to pleurigeneric level. Therefore, it is of imperative interest to unravel the all aspects of orchids in details. In the present study, the flowers of Cymbidium pendulum, an ornamental important orchids, have been investigated. It is observed that the flowers of C. pendulum started wilting in 20 days without pollination and senesced within 8 days after the act of pollination, suggesting a rapid progression of senescence related events triggered by pollination. The placenta became meristematically active only after pollination. The ovule primordium consisted of an axial filament 5–7 cells high enclosed by epidermal cells. The uppermost cell of the nucellar filament differentiated into an archesporial cell at 20–26 days after pollination (DAP), which turned into megaspore mother cell at 26–30 DAP. The megaspore mother cell underwent meiosis resulting in the formation of a triad which converted in to an eight-nucleate polygonum type of embryo sac. Thus the total time taken to reach the organized embryo sac is between 55-60 days. The results were well confirmed by study with fluorescent microscope using fluorescent dye where the pollen tubes were observed to move through base of the column (6–10 DAP) and entered the ovarian locule (8–16 DAP) and grew on either side of the each placenta, stayed there till the embryo matures and then liberated male gametes for fertilization (54–58DAP). The fertilization occurred around 58–60 DAP. In the present studies, the detailed elucidation of post pollination reproductive development, along-with temporal sequences of path of pollen tubes, have generated valuable information, advantageously useful both for academicians and breeders.

The complete chloroplast genome of Cymbidium hookerianum (Orchidaceae): genome structure and basic analysis

Cymbidium hookerianum Rchb.f. is an ornamental orchid with large flowers and delicate aroma. Here, we reported the complete chloroplast genome sequence of C. hookerianum. The total chloroplast genome cycle was 155,447 bp. It displayed a typical structure including one large single-copy (LSC, 84,186 bp) region, one small single-copy (SSC, 17,839 bp) region, and two inverted repeat (IRs, 26,711 bp). 124 genes (78 CDSs, 38 tRNAs, 8 rRNAs) were encoded by the cp genome. The average GC content of this sequence was 36.8%. The phylogenetic analysis revealed C. hookerianum and C. changningense are sisters. The groundwork of chloroplast genome would provide available reference for molecular taxonomy and breeding.

PHYLOGENETIC ANALYSIS OF CYMBIDIUM MOSAIC AND ODONTOGLOSSUM RINGSPOT VIRUSES ISOLATED FROM PHALAENOPSIS SP.

Cymbidium mosaic virus and Odontoglossum ringspot virus are the most common and widespread viruses in ornamental orchids. Infections caused by these viruses can lead to a decrease in the phenotypic diversity of orchid collections, and as a result – to their complete depletion. The aim of the study is to determine the origin of Ukrainian isolates of orchid viruses in the collection of protected soil from O.V. Fomin Botanical Garden of Taras Shevchenko National University of Kyiv. The properties of nucleotide and amino acid sequences of the coat proteins (CP) of Cymbidium mosaic virus (CymMV) and of Odontoglossum ringspot virus (ORSV) were investigated. RNAs of CymMV and ORSV were isolated from leaves of Phalaenopsis sp. collected from A.V. Fomin Botanical Garden of Taras Shevchenko National University of Kyiv, amplified through RT-PCR and sequenced. Obtained sequences were compared at nucleotide and amino acid levels with CymMV and ORSV isolates available in the GenBank. ORSV isolated in Ukraine shared 96-99 % and 93,4-98 % CP similarity to other known ORSV isolates at nucleotide and amino acid levels, respectively. CymMV isolated in Ukraine revealed approximately 77-97 % similarity for nucleotide sequences and 84-100 % for amino acid sequences to isolates from the GenBank. Phylogenetic analysis showed that studied ORSV and CymMV isolates may have common origin with some South Korean isolates.

The <i>Cymbidium goeringii</i> genome provides insight into organ development and adaptive evolution in orchids

Cymbidium goeringii is one of the important ornamental orchids, but its high-quality genome has not been previously published. Here, we report a chromosome-level genome of C. goeringii and report the gene family expansion, and contraction of the C. goeringii genome and the regulation mechanism of MADS-box genes in floral organ development. We constructed the pathways of carotenoids and anthocyanins that contribute to the different flower colors of C. goeringii and the metabolic pathways of the main components of flower fragrance. Moreover, we found the genes that regulate colourful leaves and analyzed the resistance genes involved in the adaptive evolution of C. goeringii. Our results provide valuable genomic resources for the improvement of orchids and other ornamental plants.

<p><strong>The taxonomic revision of <em>Pleione formosana</em> (Arethuseae, Epidendroideae, Orchidaceae) based on molecular, morphological and cytological analyses</strong></p>

Due to the small degree of morphological and karyotype variations, the Pleione formosana, a well-known and valuable ornamental orchid, was treated as one member of the P. bulbocodioides complex including P. bulbocodioides, P. pleionoides and P. limprichtii, as well. The taxonomy of this complex remains problematic. P. hui was described in Anfu, Jiangxi, China, but was treated as synonym of P. formosana latter, making its taxonomic status remains controversy. In this study, we used molecular, morphological and cytological analyses to identify the relationship of P. formosana and other related species. Results base on phylogenetic analyses of chloroplast DNA and nuclear ribosomal Internal Transcribed Spacer sequence datasets indicated that Anfu samples were obviously separated from the P. formosana accessions. Network analysis showed three different groups: the P. formosana group, the P. bulbocodioides complex and the hybrid group. Morphological analysis also showed that Anfu population was significantly different from other P. formosana populations. Results of chromosome ploidy analyses showed that P. formosana was diploid and Anfu population was tetraploid, indicating that they are not the same species. In conclusion, we suggest to exclude P. formosana from P. bulbocodiodes complex, and restore the speceies rank of P. hui.

Chemical Constituents of Species in the Genus Pleione (Orchidaceae) and the Implications from Molecular Phylogeny.

Pleiones are popular ornamental orchids and different species of Pleione are long being used as traditional medicine in many Asian countries. However, previous chemical investigations of the genus Pleione are restricted to only a few species. In the present study, high performance liquid chromatography (HPLC) fingerprint of Pleione plants was established, which in particular, eight common peaks were confirmed in 16 species/hybrids. Three of the compounds corresponding to the chromatographic peaks were identified by electrospray ionization tandem mass spectrometry (ESI-tandem-MS). HPLC analysis confirmed the studied taxa shared most of chemical compounds but the content of chemical compounds was significantly different between species. Comparison of hierarchical clustering result with phylogenetic tree revealed that closely related species have higher similarities in chemical constituents. In consideration of low chemical similarity between spring-flowering and autumn-flowering species, we suggest a discrimination of these two groups during medicinal use of the genus Pleione. Species with a large pseudobulb and with high content of a certain compound should be given priority in future artificial cultivation and medicinal cultivar breeding. We hope our findings will contribute to the quality control and promote conservation of such endangered plant group.

The use of a new culture medium and organic supplement to improve in vitro early stage development of five orchid species

Due to the high demand, orchid propagation by in vitro techniques has lately increased, with an emphasis on the ways to improve germination and seedling development. In this work we compare the efficiency of three classic media for orchid propagation with a newly formulated medium supplemented with almond milk. Our target species responded differently to both the media and the supplement. However, with the exception of Bulbophyllum plumatum that did not show statistical differences with the most common media, a beneficial effect on orchid development growing on the new supplemented medium was observed for Cymbidium tracyanum, Dendrobium wardianum and for the two European orchid species Dactylorhiza praetermissa and Himantoglossum robertianum, speeding up the development of the latter two species into photosynthetic stages. The new medium could be, therefore, suitable for improving the development of some ornamental orchids and terrestrial orchid seedlings included in conservation projects that need an ex situ approach.

Functional Characterization of a Dendrobium officinale Geraniol Synthase DoGES1 Involved in Floral Scent Formation.

Floral scent is a key ornamental trait that determines the quality and commercial value of orchids. Geraniol, an important volatile monoterpene in orchids that attracts pollinators, is also involved in responses to stresses but the geraniol synthase (GES) responsible for its synthesis in the medicinal orchid Dendrobium officinale has not yet been identified. In this study, three potential geraniol synthases were mined from the D. officinale genome. DoGES1, which was localized in chloroplasts, was characterized as a geraniol synthase. DoGES1 was highly expressed in flowers, especially in petals. DoGES1 transcript levels were high in the budding stage of D. officinale flowers at 11:00 a.m. DoGES1 catalyzed geraniol in vitro, and transient expression of DoGES1 in Nicotiana benthamiana leaves resulted in the accumulation of geraniol in vivo. These findings on DoGES1 advance our understanding of geraniol biosynthesis in orchids, and lay the basis for genetic modification of floral scent in D. officinale or in other ornamental orchids.

Similar mycorrhizal fungal communities associated with epiphytic and lithophytic orchids of Coelogyne corymbosa

Mycorrhizal fungi are essential for the growth and development of both epiphytic (growing on trees) and lithophytic (growing on rocks) orchids. Previous studies indicate that in lowland tropical areas, orchid mycorrhizal fungal compositions are correlated with the life form (i.e., epiphytic, lithophytic, or terrestrial) of their host plants. We therefore tested if a similar correlation exists in an orchid distributed at higher elevations. Coelogyne corymbosa is an endangered ornamental orchid species that can be found as a lithophyte and epiphyte in subtropical to subalpine areas. Based on high-throughput sequencing of the fungal internal transcribed spacer 2 (ITS2)-rDNA region of mycorrhizae of C. corymbosa, we detected 73 putative mycorrhizal fungal Operational Taxonomic Units (OTUs). The OTUs of two dominant lineages (Cantharellales and Sebacinales) detected from C. corymbosa are phylogenetically different from those of other species within the genus Coelogyne, indicating that different orchid species prefer specific mycorrhizal fungi. We also found that the Non-metric multidimensional scaling (NMDS) plots of orchid mycorrhizal fungi were not clustered with life form, the variations among orchid mycorrhizal fungal communities of different life forms were not significant, and most of the OTUs detected from epiphytic individuals were shared by the lithophytic plants, suggesting that orchid mycorrhizal associations of C. corymbosa were not affected by life form. These findings provide novel insights into mycorrhizal associations with endangered ornamental orchids.

Transcriptome analysis reveals genes associated with leaf color mutants in Cymbidium longibracteatum

Cymbidium longibracteatum is an economically important Chinese orchid well known for its silver- or gold-colored leaf color patterns, and is desired for its ornamental value. In this study, we analyzed the yellow and green rhizomes from C. longibracteatum by deep RNA-sequencing. A total of 333,497 transcripts and 162,407 unigenes of ‘longchangsu’ obtained from 39.59 Gb of clean reads. Differentially expressed gene (DEG) analysis indicated that 497 genes were upregulated and 147 downregulated in the leaf color mutant. Five of these DEGs were involved in the phototransduction pathway, and 48 genes belonged to the plant-pathogen interaction pathway. Furthermore, we identified seven genes associated with the photosystem, six of which were upregulated, and one (psbA) was downregulated. Our results showed that downregulation of psbA gene may produce leaf color mutants under certain culture conditions that affect the D1 protein of photosystem II. All seven genes were validated by qRT-PCR. This study on genes related to photosystem and other pathways establishes a genetic foundation for ornamental orchids and may help to improve the economic and breeding values of C. longibracteatum.

Pathogens associated with diseases in native orchids of the region of Southern Amazonia

The orchids have a great diversity of genus and species, which contributes to a singular wealth of flowers, that present immense variation of colors and forms. Within the trade of ornamental plants orchids constitute a promising area of agribusiness, with high added value. However, one of the major limitations for the production of these plants is the incidence of diseases, mainly caused by fungi. In this context, the objective of the study was to isolate and identify fungi from orchids with a symptomatological picture of disease of fungal etiology. The incidence of 3 genera of pathogens of fungal etiology in 10 genera of orchids was verified. The causal agent with the highest percentage of frequency was Nigrospora sp.

The complete chloroplast genome of Dendrobium wattii (Orchidaceae)

Dendrobium wattii is a rare and ornamental orchid that is placed in Sect. Formosae of Dendrobium. The complete chloroplast (cp) genome sequence and the genome features of D. wattii were reported for new data on the phylogeny of Dendrobium. The complete cp genome sequence of D. wattii is 159,366 bp in length, including a large single-copy region (LSC, 87,192 bp), a small single-copy region (SSC, 18,422 bp), and two inverted repeat sequences (IRs, 26,876 bp, each). The total content of GC is 37.2%. The cp genome contains 133 genes, consisting of 131 unique genes (79 protein-coding genes, 30 tRNAs, and 4 rRNAs). The phylogenetic analysis suggested that D. wattii be closely related to other species of Dendrobium.

Genetic Diversity and Identification of Vietnamese Paphiopedilum Species Using DNA Sequences

Paphiopedilum is among the most popular ornamental orchid genera due to its unique slipper flowers and attractive leaf coloration. Most of the Paphiopedilum species are in critical danger due to over-exploitation. They were listed in Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, which prevents their being traded across borders. While most Paphiopedilum species are distinctive, owing to their respective flowers, their vegetative features are more similar and undistinguished. Hence, the conservation of these species is challenging, as most traded specimins are immature and non-flowered. An urgent need exists for effective identification methods to prevent further illegal trading of Paphiopedilum species. DNA barcoding is a rapid and sensitive method for species identification, at any developmental stage, using short DNA sequences. In this study, eight loci, i.e., ITS, LEAFY, ACO, matK, trnL, rpoB, rpoC1, and trnH-psbA, were screened for potential barcode sequences on the Vietnamese Paphiopedilum species. In total, 17 out of 22 Paphiopedilum species were well identified. The studied DNA sequences were deposited to GenBank, in which Paphiopedilum dalatense accessions were introduced for the first time. ACO, LEAFY, and trnH-psbA were limited in amplification rate for Paphiopedilum. ITS was the best single barcode. Single ITS could be used along with nucleotide polymorphism characteristics for species discrimination. The combination of ITS + matK was the most efficient identification barcode for Vietnamese Paphiopedilum species. This barcode also succeeded in recognizing misidentified or wrongly-named traded samples. Different bioinformatics programs and algorithms for establishing phylogenetic trees were also compared in the study to propose quick, simple, and effective tools for practical use. It was proved that both the Bayesian Inference method in the MRBAYES program and the neighbor-joining method in the MEGA software met the criteria. Our study provides a barcoding database of Vietnamese Paphiopedilum which may significantly contribute to the control and conservation of these valuable species.

Quantifying the trade in wild-collected ornamental orchids in South China: Diversity, volume and value gradients underscore the primacy of supply

Despite the grave threat illegal wildlife trade poses to species survival, few studies have attempted to link supply and demand data for the same wildlife product. All ca. 29,000 orchid species are listed by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and many are protected under domestic legislation too, but a growing body of evidence suggests that orchids continue to be subject to unsustainable harvesting and undocumented trade. South China is a known black spot for trade in wild-collected ornamental orchids but understanding of the drivers determining the flow of species diversity, volume and value remains wanting. We conducted systematic monthly surveys at five markets along a West-East transect from Yunnan to Hong Kong for one year, recording variables including species, numbers of individuals, weight and price. Although wild orchid diversity is highest in Yunnan, the diversity of orchids in trade increased eastwards and mean price per stem rose more than four-fold, albeit always significantly cheaper than that for artificially produced hybrids. Part of this trade appears to be in breach of CITES. Few orchids in trade conformed to six criteria highlighted in prior demand-side studies as being of higher utility value, but most conformed to a combination of four or more, suggesting that vendors can readily offer products that meet a majority of consumer preferences. Effective supply-side regulation, through government intervention and social media campaigns, is needed to facilitate behavioural change and allow artificially propagated plants to compete in the market-place.

The complete chloroplast genome of Cymbidium changningense (Orchidaceae)

Cymbidium changningense is an ornamental orchid and endemic specie in China. Here, we report the complete chloroplast (cp) genome sequence and the cp genome features of C. changningense. The cp genome was 155,388 bp in length with a typical quadripartite structure, which was comprised of one large single copy (LSC, 84,522 bp) region and one small single copy (SSC, 20,622 bp) region separated by two inverted repeat (IR, 25,122 bp) regions. The cp genome encoded 132 genes, of which 108 were unique genes (80 protein-coding genes, 24 tRNAs, and four rRNAs). The phylogenetic analysis showed that C. changningense was sister with C. erythraeum.

Characterization and phylogenetic analysis of the complete plastome sequence of Thunia alba (Lindley) H. G. Reichenbach (Orchidaceae), a rare wild ornamental orchid

Thunia alba (Lindley) H. G. Reichenbach is a wild ornamental orchid, and it is a rare plant species with small populations. In this study, the complete chloroplast genome sequence of T. alba was assembled using short reads produced by high-throughput sequencing technologies. The whole chloroplast genome was 159,948 bp in length with a typical quadripartite structure, which consisted of a large single-copy (LSC), a small single-copy (SSC), and two inverted repeats (IRs). The sizes of LSC, SSC, and IR were 87,532, 18,852, and 26781 bp, with GC contents of 35.0%, 30.3%, and 43.2%, respectively. There were a total of 135 genes, which included 88 protein-coding genes, 8 rDNA genes, 38 tRNA genes, and a pseudogene. A phylogenetic tree was generated using the maximum-likelihood method, and the results revealed that T. alba was sister to Pleione bulbocodioides and Pleione formosana, with a support rate of 100%.