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Orchid plants are ornamental plants with various shapes, colors, and sizes, exhibiting unique characteristics that make them a special attraction for enthusiasts of ornamental plants. Among them is the Dendrobium orchid, which belongs to the genus of orchids known for its diverse types and beauty. Enhancing the growth and quality of Dendrobium Sonia-ersakul orchid flowers can be achieved through proper fertilization. The fertilizer in this research is derived from liquid organic fertilizer, Eco Enzyme. This research aims to assess the impact of Eco Enzyme on the induction of flowering growth in Dendrobium orchids. This research was carried out at CV Candi Orchid, 17 Bukit Unggul Raya Street, Semarang, over three months, from May to July 2023. The research design employed in this research is the two-tailed t-test research method, which includes a control group and an experimental group treated with 0.2% Eco Enzyme. There were two combinations, with each treatment comprising six replicates. The measured variables included the number of roots, root length, buds, and panicles. The outcomes indicated that the application of Eco Enzyme led to a significant increase in the number of panicles compared to the control group. However, no significant differences were observed in root length, the number of new roots, or the number of buds when Eco Enzyme was applied.

The small plant-specific YABBY gene family plays key roles in diverse developmental processes in plants. Dendrobium chrysotoxum, D. huoshanense, and D. nobile are perennial herbaceous plants belonging to Orchidaceae with a high ornamental value. However, the relationships and specific functions of the YABBY genes in the Dendrobium species remain unknown. In this study, six DchYABBYs, nine DhuYABBYs, and nine DnoYABBYs were identified from the genome databases of the three Dendrobium species, which were unevenly distributed on five, eight, and nine chromosomes, respectively. The 24 YABBY genes were classified into four subfamilies (CRC/DL, INO, YAB2, and FIL/YAB3) based on their phylogenetic analysis. A sequence analysis showed that most of the YABBY proteins contained conserved C2C2 zinc-finger and YABBY domains, while a gene structure analysis revealed that 46% of the total YABBY genes contained seven exons and six introns. All the YABBY genes harbored a large number of Methyl Jasmonate responsive elements, as well as anaerobic induction cis-acting elements in the promoter regions. Through a collinearity analysis, one, two, and two segmental duplicated gene pairs were identified in the D. chrysotoxum, D. huoshanense, and D. nobile genomes, respectively. The Ka/Ks values of these five gene pairs were lower than 0.5, indicating that the Dendrobium YABBY genes underwent negative selection. In addition, an expression analysis revealed that DchYABBY2 plays a role in ovary and early-stage petal development, while DchYABBY5 is essential for lip development and DchYABBY6 is crucial for early sepal formation. DchYABBY1 primarily regulates sepals during blooming. Furthermore, there is the potential involvement of DchYABBY2 and DchYABBY5 in gynostemium development. The results of a comprehensive genome-wide study would provide significant clues for future functional investigations and pattern analyses of YABBY genes in different flower parts during flower development in the Dendrobium species. [ABSTRACT FROM AUTHOR]

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Generally, orchids produce dust-like seeds in which endosperm reduction and embryo undifferentiation represent a derived state shared with species in about 11 other plant families. Orchid seeds are proposed to have a special kind of morphological or morphophysiological dormancy. We test this proposition, overcoming several design limitations of earlier studies, specifically that the in vitro germination method for orchid seeds uses pro-oxidants for disinfection and incorporates nitrate in the medium; both 'treatments' might contribute to dormancy breaking, potentially confounding judgement on the depth and nature of the dormant state. Seeds of the tropical orchid Dendrobium cruentum Rchb. f., were sown both in vitro , on a nutrient medium, and ex vitro , on plain agar omitting prior disinfection with sodium hypochlorite. Seeds previously stored and fresh seeds were incubated under combinations of vitro conditions, light treatments, constant or alternating temperatures and nitrate concentration. Seeds of D. cruentum are very small but have a large embryo that occupies most of the seed. Over a range of constant temperature seeds germinated to the spherical protocorm stage just as well ex vitro as in vitro. Neither light nor nitrate were prerequisites for ex vitro germination. The ability of D. cruentum seed to germinate in the absence of environmental or chemical stimuli suggests that mature seed can be non-dormant. Our results support the proposition that neither all DUST seed fit a dormancy class nor all orchids produce morphological or morphophysiological seeds. Finally, embryo/seed volume determinations in orchids may prove as valuable in studies on the evolution and ecology of germination and dormancy as embryo:seed ratios in other angiosperm species. [ABSTRACT FROM AUTHOR]

Exportation of cut flowers entails long distance transportation, and the quality of cut flowers deteriorates as the distance and transportation time increase. Low storage temperatures and modified atmosphere are commonly used to extend the life of cut flowers. As a result, this research explored the potential use of high CO2 and low O2 to prolong the shelf life of cut flowers. Specifically, this study examined the effects of high CO2 and low O2 storage on the biochemical changes in cut Dendrobium pink stripe orchid flowers. The experiments were conducted under normal and high CO2 and low O2 conditions, and results were compared. Under the normal condition, carbon dioxide (CO2) and oxygen (O2) concentrations were 0.03 % and 21 %. In the high CO2 and low O2 environment, CO2 was varied between 5 and 10 %; and O2 between 2, 4, 6, and 8 %. The storage temperature and relative humidity were 13 °C and 95 %. The originality of this work is the use of high CO2 and low O2 storage environments to investigate the biochemical changes in cut Dendrobium orchid flowers. The experimental results showed that high CO2 and low O2 significantly enhanced the storage life of Dendrobium orchid flowers (p < 0.05). The longest storage life of 28.33 days was achieved under 5 % CO2 and 2 % O2 atmosphere condition, compared with 11.67 days under the normal atmosphere condition. High CO2 and low O2 storage also helped to retain total anthocyanin content while lowering fresh weight loss, respiration rate, ethylene production, protein degradation, and protease activity.

This research investigated the effect of different atmosphere storage conditions on 1-aminocyclopropane-1-carboxylic acid (ACC) synthase and ACC oxidase enzyme activity; and senescence of cut Dendrobium orchid flowers. The atmosphere storage conditions under study were normal atmosphere, modified atmosphere packaging, and controlled atmosphere. Under the normal atmosphere, carbon dioxide (CO2) and oxygen (O2) concentrations were 0.03 and 21 %, respectively. For the modified atmosphere packaging, cut orchid flowers were wrapped in polypropylene film prior to filling with 5 % CO2 and 2 % O2, while under the controlled atmosphere, CO2 and O2 concentrations were maintained at 5 and 2 %, respectively. The storage temperature and relative humidity were 13 °C and 95 %, respectively. The ACC synthase and ACC oxidase activity and ethylene-induced electrolyte leakage were determined and results compared. The controlled atmosphere substantially lowered ACC synthase and ACC oxidase activity and was effective in delaying senescence of cut orchid flowers, as indicated by the longest storage life of 28.33 days, followed by the modified atmosphere packaging (18.15 days) and normal atmosphere (11.67 days). The longer storage life enables suppliers of orchid flowers to efficiently manage the demand and supply and also provides exporters with new opportunities to expand into distant overseas markets. The novelty of this research lies in the use of different storage environments to investigate the senescence mechanisms at tissue level of Dendrobium orchid flowers in response to ACC synthase and ACC oxidase enzyme activity.

Dendrobium orchid (Dendrobium nobile) is one of the popular ornamentals grown throughout the globe. It has been observed to be one of the favourable hosts for foliar nematode, Aphelenchoides besseyi. In a two years study about its seasonal population fluctuation, it was observed that the nematode remains active on plants round the year under polyhouse condition exhibiting peak population (3272.5/leaf) during the month of July with temperature (28.8-31.2oC), relative humidity (84.3-87.4%) and minimum (492.6/leaf) in the month of January with comparatively low temperature (20.3-22.3oC) and relative humidity (57.0-59.4%), respectively. [ABSTRACT FROM AUTHOR]

The Saen Saeb canal, a transportation route in the central of Bangkok, nowadays is polluted with domestic wastewater. People along the canal still use the Saen Saeb water for watering plants. However, the effect of Saen Saeb water usage on plant growth and soil microorganisms is not well understood. The present study showed the effect of Saen Saeb water on the growth of Chinese kale (Brassica alboglabra), tomato (Lycopersicon esculentum), and Dendrobium orchid (Dendrobium Sonia ‘Earsakul’) at greenhouse and sterile conditions. We found that the Saen Saeb water reduced the growth of Chinese kale and Dendrobium orchid in the greenhouse condition as well as the growth of the Chinese kale and tomato in the sterile condition. Moreover, the Saen Saeb water reduced the amount of rhizosphere microorganisms of the Chinese kale to five times less than that of tap water. Thus, this may affect the plant growth.

The Ascocenda flavanone 3-hydroxylase (AcF3H) gene was successfully transformed into Dendrobium 5N white orchid plants using Agrobacterium-mediated gene transformation. In this study, for the first time, we report the construction of a plant expression vector harboring the AcF3H gene using the Gateway cloning system. Protocorm-like bodies (PLBs) were cocultivated with the Agrobacterium tumefaciens strain AGL1 harboring the plant expression vector pGWB5-AcF3H, which contained the hygromycin phosphotransferase (hpt) gene as a selectable marker. The highest transformation efficiency (10.13%) was achieved when PLBs were cocultivated with Agrobacterium cells for 15 min. Three months after the transformation, the plantlets were regenerated, and the transgenic plants were confirmed by polymerase chain reaction (PCR) analysis using specific primers for the hpt gene and 35S promoter region. PCR products of approximately 400 and 500 bp, corresponding to the hpt gene and the 35S promoter, respectively, were detected in the transgenic plants, while no such product was observed in nontransgenic plants, indicating that the AcF3H gene was integrated into the genome of Dendrobium 5N white orchid plants. The transient expression of the AcF3H gene in Dendrobium 5N white and Dendrobium Anna petals was performed using the agroinfiltration technique and the results demonstrated that no cyanidin content was detected in the Dendrobium 5N white petals after AcF3H infiltration. In contrast, the cyanidin content was increased by approximately 6% in the Dendrobium Anna petals, suggesting that the AcF3H gene was transiently expressed in this orchid. [ABSTRACT FROM AUTHOR]

Photosynthetic physiology of Dendrobium nobile, Dendrobium pendulum, Dendrobium chrysotoxum, and Dendrobium densiflorum was studied. A bimodal diurnal variation of the net photosynthetic rate (Pn) was observed in the four Dendrobium species with the first peak [5.09 to 6.06 µmol (CO2) per m-2 ⋅ s-1] ≈ 1100 hr and the second peak [3.83 to 4.58 µ mol (CO2) per m-2 ⋅ s-1] at 1500 hr. No CO2 fixation was observed at night. For all four Dendrobium species, the light compensation point (LCP) was 5 to 10 µmol ⋅ m-2 ⋅ s-1, light saturation point (LSP) ranged from 800 to 1000 µmol ⋅ m-2 ⋅ s-1, apparent quantum yield (AQY) was 0.02, and CO2 compensation points (CCP) and saturation point (CSP) were 60 to 85 µmol ⋅ mol-1 and 800 to 1000 µ mol ⋅ mol-1, respectively. Carboxylation efficiency (CE) values ranged from 0.011 to 0.020. The optimum temperature for photosynthesis was between 26 and 30 °C. The measurement of Pn seasonal variation indicated that July to August had the higher Pn for Dendrobium species. Additionally, the chlorophyll a/b (Chi a/b) ratios of the leaves were 2.77 to 2.89. Measurement of key enzymes in the photosynthetic pathway indicated relatively high Ribulose-l,5-bisphosphate carboxylase (RuBPCase) and glycolate oxidase (GO) activities but very low phosphoenolpyruvate carboxylase (PEPCase) activities. It suggested that these four Dendrobium species are typical semishade C3 plants. [ABSTRACT FROM AUTHOR]

Gall midges of the genus Contarinia (Diptera: Cecidomyiidae) that infest the flower buds of various plant species have been newly found in Japan in recent years. Those infesting the flower buds of Pseuderanthemum laxiflorum (A. Gray) Hubbard ex Baillon (Amaranthaceae) and Jasminum sambac (Linnaeus) Aiton (Oleaceae) in Okinawa Prefecture, and Dendrobium spp. (Orchidaceae) in Mie Prefecture were identified, on the basis of morphological features and molecular information, as an invasive gall midge, C. maculipennis Felt. C. maculipennis was recorded in Mie Prefecture for the first time, and P. laxiflorum is newly regarded as one of the host plants of C. maculipennis. Three other Contarinia gall midges that we found infesting the flower buds of Lycopersicon esculentum Miller, Capsicum annuum Linnaeus (Solanaceae), and Oxalis corniculata Linnaeus (Oxalidaceae) were not identical with C. maculipennis. Among these, the first two, which infested solanaceous plants, were identical. However, the species other than C. maculipennis could not be identified to the species level because morphological differences were obscure and DNA sequencing data of allied congeners have not yet been registered on GenBank. [ABSTRACT FROM AUTHOR]