Spathoglottis Plicata Research Articles

Performance of Orchid Species in Shevaroy Hills of Eastern Ghats

Performance of 24 orchid species was assessed in the net-house of Horticultural Research Station, Tamil Nadu Agricultural University, Yercaud. Among the species studied, plant height was significantly high (105cm) in Spathoglotts plicata. At the end of the vegetative stage, number of leaves was maximum (30) in Aerides. Leaf was longest (49.8cm) and widest (17.6cm) in Rhyncostylis retusa. Paphiopedilum insigne produced largest flower size (14.4cm across). Pedicel length was highest in Phaius tankervillae (10.3cm) and Renanthera inshootiana (7.1cm). Aerides multiflorum recorded lowest pedicel length (1.24cm). Epidendrum radicans and Spathoglottis plicata produced flowers round the year. Lucia virides recorded maximum life (29 days) on plant, followed by Arachnanthe clarkei (18 days), Dendrobium densiflorum (18 days) and Oncidium flexosum (16 days), while, minimum (6 days) was observed in two orchid species, Aerides crispum and Cattleya sp. Maximum (23 days) vase life was recorded in Lucia virides. Results of the investigation thus reveal that among the 24 orchid species studied, Epidendrum radicans, Lucia virides and Paphiopediluminsigne performed better in terms of vegetative and floral characters under Shevaroy hill condition.

Ex vitro symbiotic seed germination of Spathoglottis plicata Blume on common orchid cultivation substrates

This study reports a simple and efficient method for symbiotic orchid seed germination. Seeds obtained from mature capsules of Spathoglottis plicata Blume were sown non-axenically on common orchid cultivation substrate (i.e., soil, coir dust, or peat moss) pre-inoculated with orchid mycorrhizal fungus, Epulorhiza isolate (=anamorph of Tulasnella; i.e., Da-KP-0-1 or Ps-KT-0-1). Fungal isolates and type of germination substrates were found to affect the effectiveness of this method. At seven weeks after sowing, peat moss inoculated with fungal isolate Da-KP-0-1 was the most effective in promoting seed germination and protocorm development. All other treatments with fungal inoculation yielded significantly higher germination percentages and average developmental stages of seeds/protocorms compared to control treatments. At nine weeks after sowing, protocorms with well-developed leaves and roots could be observed in all inoculation treatments but not in uninoculated controls. Since the established method does not require axenic condition during seed germination step, it should be accessible to professional growers, conservationists, and orchid amateurs alike. Additionally, a potentially antagonistic effect of Epulorhiza against Aspergillus contaminant growing from seeds was observed.

Anatomical and Cytological Features of Spathoglottis plicata from Java Island

Spathoglottis plicata is a ground orchid that displays large variation in flower features. In spite of large variation on morphological characters, its anatomical and cytological characters are not well known. This paper described the leaf anatomical and chromosomal features of S. plicata . Leaf anatomy was observed from both transverse and paradermal sections of leaves. Chromosome numbers were observed from root tip cells. Epidermis of all S. plicata variants comprised of two cell shapes, the rectangle cells located above veins, while the polygonal one located in between veins. Stomatal type was brachitetracyclic, which were only found on lower epidermis. Leaf transversal section comprised of one layer of upper and lower epidermis, spongy mesophyll, and vascular tissue. The number of leaf hair varied depended on the original habitat and altitute. All variants of S. plicata had same chromosome number (2n=40).

Auxin regulates first leaf development and promotes the formation of protocorm trichomes and rhizome-like structures in developing seedlings of Spathoglottis plicata (Orchidaceae)

Auxin flows in a polar manner to target tissues and exert its morphogenic effect. Preventing auxin movement, with polar auxin transport (PAT) inhibitors, or increasing auxin levels in tissues through exogenous application can provide a means for assessing the importance of appropriate tissue distribution and concentration of this hormone during development. The formulation of culture media for micropropagation has been the primary focus of most orchid tissue culture research, a goal that unveils seedling hormone responses at a single point in development. This study was unique because it evaluated the auxin response of orchids during three stages of seedling development. Seedlings were grown on standard culture media for 10, 35 and 85 days. Each group was sub-cultured onto auxinand/or PAT inhibitor-containing media for an additional 10, 30 and 60 days, respectively. Data were collected on first leaf initiation, trichome formation and the appearance of propagative structures. In the 20-day seedlings, auxins and PAT inhibitors promoted precocious formation and random placement of protocorm hairs rather than in tufts, as seen in older, control seedlings. The 65-day seedlings formed protocorm-like bodies, rhizome-like growths from the stem, and fleshy leaves with trichomes. Seedlings cultured for 145 days developed microshoots or callus growth in the axils of older leaves and exhibited necrosis of original seedling roots and leaves. In general, exogenously applied auxin promoted the reversion of differentiated Spathoglottis plicata seedling tissue to a morphology that had propagative properties. Additionally, auxins commonly induced hair formation, which suggests that protocorm hairs may be root hair-like in nature. This work characterized three auxin growth responses in S. plicata seedlings that have not been reported in orchids: (i) the inhibition of first leaf initiation and abnormal first leaf morphology; (ii) the promotion of trichome formation; and (iii) the induction of rhizome-like structures and microshoots at a specific stage in seedling development.

There goes the neighborhood: apparent competition between invasive and native orchids mediated by a specialist florivorous weevil

The exotic orchid, Spathoglottis plicata, has naturalized and spread rapidly over Puerto Rico where it is generally considered to be innocuous. It is abundant and occupies the same habitat as the native orchid, Bletia patula. The two are hosts to the same native weevil, Stethobaris polita, a specialist on orchid flowers. We ask whether the weevils mediate apparent competition between the two orchids. We monitored weevil populations, floral damage and fruit set in B. patula in the presence and absence of S. plicata. We also experimentally tested whether weevils preferred one species over the other. Finally, we modeled the distribution of both orchid species to predict the extent by which the two species may interact in Puerto Rico. We found a significantly lower number of weevils and a higher fruit set for B. patula where S. plicata is absent, indicative that apparent competition is occurring. The choice experiments show that weevils prefer flowers of S. plicata over those of B. patula, but B. patula still sustained considerable damage. The current distribution of the native B. patula is nearly limited to the northern karst region of Puerto Rico. The naturalized S. plicata has a broader range and the models predict that its distribution will strongly overlap with that of B. patula. We expect the S. plicata invasion to continue and affect native orchids through apparent competition as long as the presence of S. plicata maintains elevated weevil populations. Thus, even seemingly harmless invasive orchids can have subtle but significant negative consequences.

Isolation and phylogenetic relationship of orchid-mycorrhiza from Spathoglottis plicata of Papua using mitochondrial ribosomal large subunit (mt-Ls) DNA

Sufaati S, Agustini V, Suharno. 2012. Isolation and phylogenetic relationship of orchid-mycorrhiza from Spathoglottis plicata of Papua using mitochondrial ribosomal large subunit (mt-Ls) DNA. Biodiversitas 13: 59-64. All terrestrial mycorrhiza have mutual symbiotic with mycorrhizal fungi in order to gain nutrient from surrounding environment. This study was done to isolate and to identify mycorrhiza orchid that associates with Spathoglottis plicata and were collected from Cagar Alam Pegunungan Cycloops (CAPC), Jayapura. Isolation of mycorrhizal orchid came after the modified method of Manoch and Lohsomboon (1992). The result showed that based on the morphological characteristic, there were presumably 14 isolations. However, only 2 isolations have been known, namely Rhizoctonia sp. and Tulasnella sp., while the rest were not identified yet. Among them, the DNA of the 11 isolations were able to beextracted for further analysis. The constructed phylogenetic tree performed that those species could be grouped into 4 major clusters. Two species, Rhizoctonia sp. and Tulasnella sp. were in different clusters.

EX SITU ORCHID CONSERVATION - A CASE STUDY FROM THE SINGAPORE BOTANIC GARDENS

Some 226 species of native orchids have been recorded in Singapore. Of these, 178 are considered to be extinct, 40 are critically endangered, one is endangered (Bulbophyllum vaginatum), two are vulnerable (Vanilla griffithii, Bulbophyllum trifolium), and only five are considered to be common (Arundina gramminifolia, Bromheadia finlaysonianum, Dendrobium crumenatum, Eulophia graminea, Spathoglottis plicata). The orchid conservation program at the Singapore Botanic Gardens aims to monitor existing species, explore ways to conserve their germplasm, and increase their number for subsequent re-introduction into appropriate habitats, including managed parks and roadsides. Thus far, we have successfully re-introduced Grammatophyllum speciosum, Bulbophyllum vaginatum, Bulbophyllum membranaceum, Cymbidium finlaysonianum and Cymbidium bicolor. A special designated area at the National Orchid Garden has been set up to showcase the rich diversity of native species. The Orchid Cryo-Seed Bank began several years ago and is showing some promising results. We have successfully stored seeds of several native species including Cymbidium finlaysonianum, Cymbidium bicolor, Grammatophyllum speciosum, Dendrobium crumenatum, Spathoglottis plicata, Bulbophyllum vaginatum, and Dendrobium anosmun.

CHLOROPLAST DNA BARCODING OF SPATHOGLOTTIS SPECIES FOR GENETIC CONSERVATION

Spathoglottis is one of the most popular terrestrial orchids because it is attractive, easy to cultivate and continuously blooms throughout the year. It is a native orchid of Malaysia and listed as an endangered species. Therefore, this species needs to be conserved for commercial and environmental purposes. DNA barcoding is a technique for species identification, which uses a short DNA sequence from a standard and agreed-upon position in the genome. This technique plays an important role in biodiversity conservation for animals but is not yet well established in plants. Chloroplast DNA was chosen for this study aimed at building a DNA barcoding of Spathoglottis species. Seven species of Spathoglottis were used to carry out this study. They were Spathoglottis plicata, Spathoglottis gracilis, Spathoglottis aurea, Spathoglottis plicata alba, Spathoglottis unguiculata, Spathoglottis kimbaliana and a Spathoglottis hybrid. Eight regions (i.e., accD, matK, ndhJ, rpoB, rpoC1, ycf5, rbcL-a and trnH-psbA) in the chloroplast genome and two regions (i.e., ITS1 and ITS2) in the nuclear genome were selected and screened in order to define a universal barcoding region across all the seven selected species. The study found that the four chloroplast regions (i.e., matK, rbcL-a, rpoB and rpoC1) were successfully amplified from all the tested species. The DNA sequencing from each chloroplast region was compared among the species and analyzed to differentiate the intra- and inter-genetic variations. The analysis of chloroplast regions was done for single regions and as a combination of the four regions. The haplotypes for the multiple analyses showed sufficiently high resolution to enable differentiation between the selected Spathoglottis species. In conclusion, this study showed that the chloroplast DNA regions had high potential to be developed for DNA barcoding of Spathoglottis species. This is the first step towards the development of universal DNA barcoding technique for all native orchids in Malaysia.

Neurologie centrale : testing or not testing ?: Central neurology: testing or not testing?

This study reports a simple and efficient method for symbiotic orchid seed germination. Seeds obtained from mature capsules of Spathoglottis plicata Blume were sown non-axenically on common orchid cultivation substrate (i.e., soil, coir dust, or peat moss) pre-inoculated with orchid mycorrhizal fungus, Epulorhiza isolate (=anamorph of Tulasnella; i.e., Da-KP-0-1 or Ps-KT-0-1). Fungal isolates and type of germination substrates were found to affect the effectiveness of this method. At seven weeks after sowing, peat moss inoculated with fungal isolate Da-KP-0-1 was the most effective in promoting seed germination and protocorm development. All other treatments with fungal inoculation yielded significantly higher germination percentages and average developmental stages of seeds/protocorms compared to control treatments. At nine weeks after sowing, protocorms with well-developed leaves and roots could be observed in all inoculation treatments but not in uninoculated controls. Since the established method does not require axenic condition during seed germination step, it should be accessible to professional growers, conservationists, and orchid amateurs alike. Additionally, a potentially antagonistic effect of Epulorhiza against Aspergillus contaminant growing from seeds was observed.

Isolation of a White Flowered Mutant through Seed Culture in Spathoglottis plicata Blume

Spathoglottis plicata Blume, a terrestrial orchid having prolonged inflorescence with beautiful lilac (pinkish purple) coloured flowers, is commercially important. Treatment of its seeds with sodium azide induced strikingly attractive flower colour modification exploiting seed culture protocols. Vacin and Went (VW) (1949) medium stimulated seed germination and after supplementation with ripe banana extract yielded maximum germination frequency in all cases; it was followed with ripe tomato extract and yogurt water (semi-solid liquor from fermented milk) in untreated and post-treated seeds respectively. The magnitude, however, reduced in treated seeds. Germination initiated usually on the 20th day of inoculation, while addition of yogurt water induced earlier germination by 9 days in the treated and 7 days in untreated samples. Repeatedly subcultured 60 days old plantlets were gradually acclimatized growing inside a hardening chamber and subsequently in a glass house. A treated plant with deep green leaves showed conspicuous variation from the mother strain by its charming milk-white flower colour and green floral bracts in contrast to lilac coloured flower and floral bracts in the latter. VM2 progeny retained the mutant phenotype and genetic uniqueness as indicated by specific PAGE protein banding profile. The mutant having completely different flower colour modification with milky whiteness possesses special floricultural significance and may, therefore, be treated as a new horticultural variety.

Differential mechanisms to induce dehydration tolerance by abscisic acid and sucrose in Spathoglottis plicata (Orchidaceae) protocorms

ABSTRACTAbscisic acid (ABA) and sucrose are known to induce dehydration tolerance of in vitro plant cells and tissues. The present study reports the presence of different mechanisms by which sucrose and ABA improve dehydration tolerance of Spathoglottis plicata (orchid) protocorms. Orchid protocorms were generated aseptically from seeds on Murashig and Skoog medium, and then treated for 7 d in medium containing 10 mg L−1 ABA and/or 10% (w/v) sucrose. Dehydration tolerance of protocorms was determined at ∼25 °C under various drying conditions at relative humidity from 7 to 93%. The actual rate of water loss (i.e. drying rate) was determined using the rate constant of tissue water loss during drying according to the first‐order kinetics. Drying rate affected dehydration tolerance. ABA treatment reduced drying rate and increased dehydration tolerance of protocorms at all relative humidity values tested. However, when compared on the basis of actual drying rates, there was no difference in dehydration tolerance between control and ABA‐treated protocorms, suggesting that ABA‐induced tolerance was correlated with the drying rate reduction. Sucrose treatment was more effective than ABA treatment for the induction of dehydration tolerance. Interestingly, sucrose only slightly affected drying rate. ABA treatment significantly enhanced the synthesis of dehydrin, whereas sucrose treatment primarily resulted in sucrose accumulation. Sucrose treatment also affected protein turnover during drying, causing a significant decrease in protein content in protocorms. Slow drying promoted the degradation of high molecular weight proteins and enhanced the synthesis of low molecular weight dehydrin. The data suggest that different physiological mechanisms are probably involved in the induction of dehydration tolerance by ABA and sucrose treatment.

Significance of Unusual Features of the Anthers of Spathoglottis plicata Bl.

Significance of Unusual Features of the Anthers of Spathoglottis plicata Bl.

Infection of Spathoglottis plicata (Orchidaceae) seeds by mycorrhizal fungus

Spathoglottis plicata seeds were encapsulated in 4-mm-diameter capsules of alginate-chitosan or alginate-gelatin and infected with the mycorrhizal fungus Rhizoctonia AM9. The encapsulated seeds were placed directly on Rhizoctonia culture. About 66% of the seeds encapsulated in sucrose-free chitosan-alginate established a symbiotic relationship with the mycorrhizal fungus after co-culturing for 2 weeks. The highest percentage of infection observed was about 84%. Addition of sucrose or using gelatin-alginate for encapsulation reduced the percentage of infection by about half. The growth of Rhizoctonia AM9 in sucrose-free alginate, chitosan and gelatin was found to be minimal. The advantages of germinating orchid seeds, encapsulated in sucrose-free polymers, through mycorrhizal infection is discussed.

Two-coat systems for encapsulation of spathoglottis plicata (Orchidaceae) seeds and protocorms

Complex coacervation of alginate-chitosan and alginate-gelatin were used to develop two-coat systems for the encapsulation of Spathoglottis plicata seeds and protocorms (top-shaped structures formed after seed germination of orchids). Both the seeds and the protocorms could withstand the encapsulation treatments with high viability. About 54% of seeds and 40% of large protocorms (1.6-2.0 mm) were able to tolerate a 6-h desiccation treatment. However, viability of the small protocorms (0.7-0.9 mm) was greatly reduced if they were desiccated before encapsulation. Encapsulation after desiccation significantly increased the percentage viability of seeds and protocorms. Treatment with abscisic acid (ABA, 10(-5) M) before desiccation and encapsulation resulted in high percentage viability in seeds and large protocorms whereas the small protocorms were found to be less tolerant to the treatments. Copyright 1998 John Wiley & Sons, Inc.

Two‐coat systems for encapsulation of Spathoglottis plicata (Orchidaceae) seeds and protocorms

Complex coacervation of alginate–chitosan and alginate–gelatin were used to develop two-coat systems for the encapsulation of Spathoglottis plicata seeds and protocorms (top-shaped structures formed after seed germination of orchids). Both the seeds and the protocorms could withstand the encapsulation treatments with high viability. About 54% of seeds and 40% of large protocorms (1.6–2.0 mm) were able to tolerate a 6-h desiccation treatment. However, viability of the small protocorms (0.7–0.9 mm) was greatly reduced if they were desiccated before encapsulation. Encapsulation after desiccation significantly increased the percentage viability of seeds and protocorms. Treatment with abscisic acid (ABA, 10−5 M) before desiccation and encapsulation resulted in high percentage viability in seeds and large protocorms whereas the small protocorms were found to be less tolerant to the treatments. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 59:635–639, 1998.

Micropropagation of Spathoglottis plicata

A rapid and reliable micropropagation method was established for Spathoglottis plicata. Nodal and leaf explants dissected from 8-month-old pot-grown seedlings were cultured on charcoal-amended Murashige and Skoog medium supplemented with 16 combinations of α-naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BA) at concentrations of 0.54-10.74 µM. Regeneration of protocorm-like bodies (PLBs) and subsequent plantlet development were observed from 98.5% of the nodal explants. Only 6.5% of leaf explants and occasionally some root segments (dissected from regenerated plantlets) were able to produce PLBs and then plantlets. The optimum plant growth regulator (PGR) combination for maximal PLB regeneration was 5.37 µM NAA and 0.44 µM BA. The best combination of PGR for plantlet development was 2.69-10.74 µM NAA and 8.88 µM BA. The NAA to BA ratios for maximal PLB induction and plantlet development were 12.2 and 0.3-1.2, respectively. Regenerated PLBs and plantlets, when cut into pieces of less than 1 mm and subcultured onto the above media, regenerated new PLBs and plantlets in another 3 months.

Two Tropical Plants as Plant Materials for Teaching Seed Germination

A local ground orchid, Spathoglottis plicata Blume, and coconut, Cocos nucifera L., were used in the classroom to teach seed germination. S. plicata, a common orchid on Guam, was utilized to demonstrate the aseptic culture of seeds under non-sterile conditions. The procedures were done in the classroom without a laminar air-flow cabinet. Nonsterile seeds were sown on growing media which were prepared without autoclaving, but by incorporating sodium hypochlorite into the media. Students had a high rate of success in germinating the orchid seeds without contamination by spraying sodium hypochlorite on the seeds. Different stages of coconut seed development were presented to students by simply cutting coconut in half. Unique features and botanical terms of coconut seed development can be taught throughout the year. Teaching materials on seed germination of the two tropical plants are being developed by print-on-demand methods.

DNA synthesis and mRNA accumulation during germination of embryos of the orchidSpathoglottis plicata

Germination of embryos of the orchid,Spathoglottis plicata Blume involves the formation of a protocorm in which DNA synthesis and cell divisions are confined to the proximal end whereas cells at the distal end undergo enlargement. Although3H-thymidine was incorporated into the distal cells of the embryo during the early period of germination, DNA synthesis was not followed by mitosis and cytokinesis. Poly(A)-RNA detected by in situ hybridization of sections to3H-poly-(U) was present uniformly in all cells of the embryo of the dry seed. However, coincident with the formation of the apical meristem, there was an increase in the density of auto-radiographic silver grains in the cells of the embryo, with a concentration of silver grains in the proximal part. The results indicate that regulatory events in the embryo prior to seed maturity determine the fate of its proximal and distal parts during germination.

DIURNAL STOMATAL AND ACIDITY RHYTHMS IN ORCHID LEAVES

SUMMARYThe stomata of Arachnis cv. Maggie Oei, Aranda cv. Deborah, Arundina graminifolia, Bromheadia finlaysoniana, Cattleya bowringiana×C. forbesii and Spathoglottis plicata (Orchidaceae) occur only on the lower epidermis of the leaves and are located within hyperstomatic chambers formed by cuticular ledges extending from the guard cells. Arachnis, Aranda and Cattleya have thick leaves which exhibit Crassulacean acid metabolism, and their stomata open when acidity levels are lowest, or shortly thereafter. Aranda and Arachnis require higher light intensities for sufficient deacidification to permit stomatal opening than Cattleya. Stomata of the thin‐leaved Arundina, Bromheadia and Spathoglottis open during the day. The stomatal rhythms, morphology and distribution, as well as the pathways of carbon fixation and light requirements for deacidification, reflect the natural habitat of each species or the parents of the three hybrids.

NON‐SPECIFICITY OF SYMBOTIC INFECTION IN ORCHID MYCORRHIZA

SummarySymbiosis tests carried out between orchids from several geographical localities and thirty‐two Rhizoctonias isolated from orchids, non‐orchid hosts and soils of worldwide distribution, showed no evidence of any species‐to‐species relationship between orchid and fungus. Dactylorhiza purpurella established a symbiotic relationship with most fungi tested while Coeloglossum wide, Goodyera repens and Cymbidium canaliculatum, although less frequently symbiotic, established compatible infections with many isolates. Among orchids with photo‐synthetic protocorms, Epidendrum radicans was compatible with several fungi but three other species of Epidendrum together with Spathoglottis plicata and a Laeliocattleya cultivar were symbiotic only with Tulasnella calospora and certain Ceratobasidium isolates. Tulasnella calospora may be a universal orchid symbiont. Ceratobasidium cornigerum and Thanatephorus orchidicola commonly occur as root endophytes but are doubtfully symbiotic with most orchids. T. cucumeris is frequently symbiotic with Dactylorhiza purpurella but less commonly so with other orchids tested.