Rhynchostylis Gigantea Research Articles

Effect of Natural Additives Modification Medium on in vitro Culture of Rhynchostylis gigantea (Lindl.) Ridl. by Tissue Culture Technique

Effect of Natural Additives Modification Medium on in vitro Culture of Rhynchostylis gigantea (Lindl.) Ridl. by Tissue Culture Technique

The of Effects of Light and a Combination of Growth Regulators on the Induction of Somatic Embryogenesis in Orchid Rhynchostylis gigantea (LindI.) Ridl.

The squirrel-tail orchid (Rhynchostylis gigantea) belongs to the Orchidaceae family. This orchid is indigenous to Southeast Asia and is scented and arranged in a bouquet of dangling stems. Its uniqueness makes it commercially desirable. In vitro culture has been utilized for orchid proliferation for a very long time to aid in the development of orchid seedlings. However, not all orchid species react the same way. Through somatic embryogenesis without gamete fusion, in vitro culture techniques can produce new plants during the entire embryonic phase. Endogenous and exogenous hormones, as well as light, influence the success of embryogenesis. Determining the optimal environmental parameters (light, combination and concentration of growth regulators, and their interaction) for inducing somatic embryogenesis from leaf explants in R. gigantea is the purpose of the present study. The leaves of R. gigantea clone 19 were utilized as explants in this investigation, utilizing a completely random factorial design. The first factor is a combination of growth regulator types and concentrations, and the second factor is light. Explants that are alive and growing at a rapid rate indicate that the in vitro culture is successful. Light and the combination of growth regulators significantly affected the percentage of viable explants, the beginning date of callus formation, and the number of embryogenic calluses produced. The interaction of two components (light and a combination of growth regulators) did not affect the three characteristics, with the exception of the proportion of somatic embryogenesis. Incubation in the dark is the optimal environment for initiating somatic embryogenesis in explants. The optimal combination of plant growth regulators for inducing somatic embryogenesis was 0.5 mgL-1 TDZ and 0.1 mgL-1 BAP. Bright light and a concentration of 1.0 mgL-1 TDZ + 0.1 mgL-1 BAP were the optimal interaction conditions for the induction of somatic embryogenesis in R. gigantea.

RAPD Profiles of Rhynchostylis gigantea (Lindl.) Ridl. Collected from Puspa Nirmala Orchids Banyumas, Central Java

Rhynchostylis gigantea (Lindl.) Ridl. is an orchid species spread over Southeast Asia countries. This species is very popular among ornamental plant collectors, especially due to its densely pack inflorescences. Hence, it is commercially found in many ornamental plant nursuries, such as Puspa Nirmala Orchids Banyumas, Central Java. Further development of the species should be supported by scientific data, particularly regarding the genetic variation. One of the molecular markers commonly used to study genetic variation is Random Amplified Polymorphic DNA (RAPD). This study aims to assess genetic variation of R. gigantea cultivars of Puspa Nirmala Orchids Banyumas collection by RAPD profiles. Genomic DNAs were extracted from leaf samples of eight R. gigantea individuals, while RAPD markers were amplified using five random primers (OPA-15, OPK-16, OPP-15, OPP-08 and OPO-08). Descriptive analysis was employed on the data obtained. It was revealed that all of the primers resulted in a 100% monomorphism. This indicates an extremely low genetic variation among R. gigantea population of Puspa Nirmala Orchids collection, which is probably due to the same origin from a selected hybrid of the same crosses.

Some physiological and biochemical changes of micropropagated Rhynchostylis gigantea during ex vitro acclimatization and greenhouse stages

The ex vitro acclimatization and greenhouse periods play a significant role for the in vitro originated plantlets. In these stages, the micropropagated plantlets have to rapidly adapt to environmental changes. Rhynchostylis gigantea is widely in vitro produced due to highly aesthetic and economic value. The aim of this work was to update the physiological changes of micropropagated R. gigantea plantlets during ex vitro acclimatization and greenhouse stages. The analysis results showed that leaf water content was significantly decreased at day 14 (90.36%) and day 28 (90.17%) stages but increased at day 84 (92.52%) and day 140 (92.34%) stages in compared to in vitro stages, day 0 (92.7%). Dry matter content was changing in the opposite direction to the leaf water content with the highest values at day 14 (9.63%) and day 28 (9.83%), respectively. The leaf transpiration rate was the highest at day zero (0.146 g/dm2/h) in compared to all other studied points. Oppositively, GPX activity was the lowest in plantlets at day zero (13.2 UI/g fresh leaf ) and the highest in planlets at day 14 (36,4 UI/g fresh leaf ). The leaf proline content was higher at day 7 and day 14 stages (132.3 and 150.8 m g/g fresh leaf, respectively) but lower at day 84 and day 140 stages (44.3 and 53.3 microgram/g fresh leaf, respectively) than at day zero (73.7 microgram/g fresh leaf ).

The First Report of Fusarium sacchari Causing Yellow Leaf Spot Disease on Rhynchostylis gigantea Orchids in Thailand

Yellow leaf spot disease was observed on Rhynchostylis gigantea orchids on an orchid farm in the Nonthaburi province of Thailand. Symptoms started with yellowish patches lacking definitive borders on the leaves of the orchids. The patches slowly expanded and merged, creating larger patches; a brown spot or black necrotic area then emerged at the center of some of the patches. R. gigantea leaves exhibiting these symptoms were used as the source for isolation studies. Based on the morphological characteristics of the fungal isolate (colony appearance, macroconidia, microconidia, conidiophore and chlamydospore structures), phylogenetic analysis of translation elongation factor-1α sequence and fulfillment of Koch’s postulates, the causative pathogen was identified as Fusarium sacchari. To our knowledge, this study is the first to report F. sacchari as a pathogen of R. gigantea.

MICROPROPAGATION OF RHYNCHOSTYLIS GIGANTEA ORCHID BY SOMATIC EMBRYOGENIC CULTURES

Rhynchostylis gigantea is a wild orchid species commonly grown. Flowering at the traditional Tet holiday, the flower season always blooms in December of the lunar calendar. The flower has a faint aroma, so it is called Nghinh spring and is a kind of orchid with a national soul and national essence. Rhynchostylis gigantea is found in many areas in Vietnam as it is distributed in the South Central Highlands, especially the areas bordering Laos and Cambodia at low altitudes <600m. Rhynchostylis gigantea is a type of heat-resistant orchid, with suitable temperatures for orchid being from 26-30oC. Rhynchostylis gigantea species have many different colors such as red, white, shrimp brick color, blue and pink. The single-member tree does not assume pseudobulbs, grows vertically, has many pneumatophores and grows straight from the stem. Rhynchostylis gigantea grows slowly and regenerates with seeds. Due to high genetic diversity, it is difficult to maintain the parent’s characteristics. Applying techniques of somatic embryo culture in conservation and development of the Rhynchostylis gigantea tree to meet the increasing demand for seedlings is urgent.

Karakterisasi Morfologi Anggrek (Orchidaceae) di Hutan Kecamatan Ngaliyan Semarang

Orchid is one ofthe flowering plants with a very high level of diversity, including the diversity of morphological characters it has. This study aims to determine the diversity of orchids (orchidaceae) seen morphologically in the Ngalian sub-district forest in Semarang city. The method used in this study is cruise method and characterization techniques. Analysis of research data was carried out descriptively and displayed in the form of tables and photos. Orchids in the teak forest cover 940 ha, spread in 4 villages, namely Wonosari village, Gondoriyo village, Podorejo village and Wates village. The results showed that there were 3 types of orchid plants (orchidaceae). The types of orchids include Rhynchostylis retusa (L.) Bi., Rhynchostylis gigantea (Lindl.) Rindl. and Dendrobium crumenatum (L.) Sw. The diversity of morphological characters in each species of orchid such as diversity in leaf color, leafshape, leaftip shape, stem color, root type etc.

Micropropagation of Rhynchostylis gigantea (Lindl.) Ridl. (Chang Phueak) through protocorm like-bodies: effects of plant growth regulators, characteristics of protocorm and strength culture media

Micropropagation of <i>Rhynchostylis gigantea</i> (Lindl.) Ridl. (Chang Phueak) through protocorm like-bodies: effects of plant growth regulators, characteristics of protocorm and strength culture media

A Framework for Assessing Supply‐Side Wildlife Conservation

Market-based, supply-side interventions such as domestication, cultivation, and wildlife farming have been proposed as legal substitutes for wild-collected plants and animals in the marketplace. Based on the literature, we devised a list of the conditions under which supply-side interventions may yield positive conservation outcomes. We applied it to the trade of the orchid Rhynchostylis gigantea, a protected ornamental plant. We conducted a survey of R. gigantea at Jatujak Market in Bangkok, Thailand. Farmed (legal) and wild (illegal, protected) specimens of R. gigantea were sold side-by-side at market. These results suggest farmed specimens are not being substituted for wild plants in the marketplace. For any given set of physical plant characteristics (size, condition, flowers), the origin of the plants (wild vs. farmed) did not affect price. For all price classes, farmed plants were of superior quality to wild-collected plants on the basis of most physical variables. These results suggest wild and farmed specimens represent parallel markets and may not be substitutable goods. Our results with R. gigantea highlight a range of explanations for why supply-side interventions may lack effectiveness, for example, consumer preferences for wild-collected products and low financial incentives for farming. Our results suggest that market-based conservation strategies may not be effective by themselves and may be best utilized as supplements to regulation and education. This approach represents a broad, multidisciplinary evaluation of supply-side interventions that can be applied to other plant and animal species.

Determination of Volatile Constituents of Thai Fragrant Orchids by Gas Chromatography-Mass Spectrometry with Solid-Phase Microextraction

Volatile constituents of four Thai fragrant orchid species, Rhynchostylis gigantea Ridl., Rhynchostylis gigantea var. harrisonianum Holtt., Vanda coerulea and Dendrobium parishii Rchb. f., were examined by Gas Chromatography-Mass Spectrometry (GC-MS). Three parts of each plant sample (the flowers, leaves and roots) were analyzed for volatile compounds using the Headspace – Solid-Phase Microextraction method (HS-SPME). Alcohols, aldehydes, alkanes, esters, ethers, ketones, monoterpenes and sesquiterpenes were identified quantitatively from the volatile compounds isolated from the flower parts. The aromatic compounds isolated differed among the orchid species. The major aromatic compounds of the flowers of R. gigantea, R. gigantea var. harrisonianum, V. coerulea and D. parishii. were nerol (25.42%), 2,3-dihydrofarnesol (34.30%), nonanal (34.69%) and 2-pentadecanone (43.47%), respectively.

Effects of Day-length and Gibberellic Acid (GA3) on Flowering and Endogenous Hormone Levels in Rhynchostylis gigantea (Lindl.) Ridl.

Effects of day-length and GA3 on flowering and endogenous hormone levels during flowering process of Rhynchostylis gigantea (Lindl.) Ridl. were studied. Three-year-old plants were grown under natural condition and short-day (10 h of light) combined with GA3 at 0 and 3,000 ppm, for 3 months. The results revealed that short-day could induce flower faster than natural condition around two weeks. Short-day and natural condition had effects on stem height and bush width, while GA3 had effects only on number of leaves per plant. ABA in leaf seemed to decreased in all treatments accept under NC-GA3, there was a peak of ABA at 30 days. Furthermore, under SD, GA3 seemed to decrease ABA in leaf. In shoot, ABA concentration was increased during 0-30 days in all treatments, after that GA3 seemed to decrease ABA concentration under NC, while the ABA concentration kept constancy under SD. On the other hand, GA3 seemed to boot t-ZR up in leaf under SD, but did not in shoot, where GA3 seemed to drop t-ZR. The reducing ABA and increasing t-ZR in leaf and/ or shoot might be related to flower buds initiation and early flowering of R. gigantea, especially, under SD.

APPLICATION OF CHITOSAN ON IN VITRO GROWTH OF RHYNCHOSTYLIS GIGANTEA PROTOCORMS AND SEEDLINGS

One-month-old protocorms of Rhynchostylis gigantea (approximately 20 to 30 mm in diameter) derived from in vitro seeds propagation were cultured on modified Vacin and Went (VW) medium supplemented with chitosan at the concentration of 0 (control), 10, 20, 40 and 60 mg/L for two months. After this only seedlings that had one leaf with 1 or 2 roots were selected and sub-cultured on to the same medium and further sub-cultured every month for 6 months. Growth of the protocorms was measured every 2 months. Seedlings cultured on VW supplemented with 60 mg/L of chitosan for two months had the highest number of leaves (3.6±-0.25). Whereas, the seedlings cultured on VW supplemented with chitosan at 40 mg/L had the highest number of roots (4.0±0.71). After four months, seedlings cultured on VW supplemented with 40 mg/L of chitosan had the highest leaf length, leaf width and leaf area (2.2±0.19, 0.7±0.05 cm and 1.4±0.19 cm 2 , respectively). Six months after culture, seedlings cultured on VW supplemented with 40 mg/L of chitosan had the highest stem fresh and dry weight and number of roots (1.452±0.16, 0.082±0.01 g and 7.5±0.47, respectively). VW supplemented with 10 mg/L of chitosan increased the number of leaves, plant height and root dry weight (4.3±0.12, 1.3±0.08 cm and 0.084±0.01 g, respectively). While seedlings grown in VW supplemented with 20 mg/L of chitosan had the longest root length (2.3±0.27 cm). However, there was no seedling survived in VW supplemented with 60 mg/L of chitosan after 4 months cultured.

In vitro propagation of white-flower mutant of Rhynchostylis gigantea (Lindl.) Ridl. through immature seed-derived protocorm-like bodies

Rapid in vitro propagation of white-flower mutant of Rhynchostylis gigantea (Lindl.) Ridl. was established for the first time through 4 month old immature seed-derived protocorm-like bodies (PLBs). 75% of PLBs developed from immature seeds cultured on half-strength MS medium with 0.05 mg·l-1 6-BA and 0.2 mg·l-1 NAA within 70 days upon transfer to MS medium with 2.0 mg/l-1 BA and 1.0 mg·l-1 NAA were induced to produce callus. Maintenance of the callus was achieved by subculturing the callus at an interval of 2 months on medium having the same level of growth regulators. The callus turned up to protocorm-like bodies upon transfer to hormone-free MS medium after 30 days of culture and later developed to shoots with 2-4 leaves. Transfer of the emerged shoots to half strength MS medium containing 100 g·l-1 banana homogenate facilitated root development and shoot growth. Plantlets established ex vitro exhibited 95% survival. Key words: Plant regeneration, protocorm, Rhynchostylis gigantea (Lindl.) Ridl., somatic embryogenesis.

High frequency shoot regeneration from Rhynchostylis gigantea (orchidaceae) using thin cell layers

Often regeneration in orchids is only achieved through protocorms, i.e., the juvenile stage. In order to produce directly shoots via bud regeneration both rapidly and with a high frequency, a transverse thin cell layer (tTCL) method is extended to Rhynchostylis gigantea. Transverse thin cell layer (tTCL) explants (0.3--0.5 mm) excised along the stem from the basis to the shoot tip of one-year-old plantlets were cultured on Murashige and Skoog (1962) medium supplemented with different combinations of benzyladenine (BAP), 1-naphthaleneacetic acid (NAA), thidiazuron (TDZ) and 3% sucrose. The optimal combination for maximal bud regeneration was 3 µM BAP and 3 µM TDZ, giving rise to 11.7 buds per tTCL. Roots were obtained with 10 µM forchlofenuron (CPPU) and 1% sucrose. The in vitro plants (> 3 cm long) obtained 4 to 6 weeks after the tTCLs culture were transferred to the greenhouse; their morphology was normal. Efficient micropropagation of direct production of shoots without passing through protocorm stage of orchid species can be achieved using the thin cell layer (TCL) method.

Acidovorax avenae subsp. cattleyae . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Acidovorax avenae subsp. cattleyae . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Cattleya spp., Phalaenopsis spp., and hybrids. The following have been reported: Catasetum Ecuador, Cattleya harrisoniana, C. warneri, C . Margaret Stewart × Schomburgkia thomsoniana, Cypripedium sp., Dendrobium sp., D . Joan Krishima, D . Sue Cornell, Doritaenopsis Clarelen, × Epidendrum obrienianum, E. pamplonense var. variegatum, Epiphronites veitchii , × Ionopsis utricularioides, Miltonia sp., Oncidium ampliatum, O. lanceanum, O. luridum, O. warscewiczii, Ornithocephalus bicornis, Phalaenopsis amabilis, Renanthera Brookie Chandler × Phalaenopsis Dos Pueblos, × Rodricidium Tahiti, Rodriguezia secunda, Rhynchostylis gigantea, R. gigantea alba, R. retusa, Sophronitis carnus, Trichocentrum tigrinum × Oncidium lanceanum, Vanda Alexander Bowman × Vanda Jennie Hashimoto, Vanda Bill Sutton, Vanda coerulescens, Vanda parishii × Phalaenopsis lueddemanniana and Vanilla sp. DISEASE: Leaf spots. The bacteria are thought to enter the plant through the stomata; lesions initially appear water-soaked and will blacken with age; a considerable amount of exudate may also be observed. Lesions can occur on any part of the leaf, older spots may be surrounded by a light green or yellow halo. The disease can kill seedlings and, with certain varieties, mature plants, should the infection reach the growing point. GEOGRAPHICAL DISTRIBUTION: Philippines, Taiwan, Italy, USA (Florida, CA), possibly Portugal (61, 284). TRANSMISSION: Bacterial exudate from heavily infected plants may act as source of inoculum.