Orchid Plants Research Articles

Detection and Characterization of Antibacterial Siderophores Secreted by Endophytic Fungi from Cymbidium aloifolium.

Endophytic fungi from orchid plants are reported to secrete secondary metabolites which include bioactive antimicrobial siderophores. In this study endophytic fungi capable of secreting siderophores were isolated from Cymbidium aloifolium, a medicinal orchid plant. The isolated extracellular siderophores from orchidaceous fungi act as chelating agents forming soluble complexes with Fe3+. The 60% endophytic fungi of Cymbidium aloifolium produced hydroxamate siderophore on CAS agar. The highest siderophore percentage was 57% in Penicillium chrysogenum (CAL1), 49% in Aspergillus sydowii (CAR12), 46% in Aspergillus terreus (CAR14) by CAS liquid assay. The optimum culture parameters for siderophore production were 30 °C, pH 6.5, maltose and ammonium nitrate and the highest resulting siderophore content was 73% in P. chrysogenum. The total protein content of solvent-purified siderophore increased four-fold compared with crude filtrate. The percent Fe3+ scavenged was detected by atomic absorption spectra analysis and the highest scavenging value was 83% by P. chrysogenum. Thin layer chromatography of purified P. chrysogenum siderophore showed a wine-colored spot with Rf value of 0.54. HPLC peaks with Rts of 10.5 and 12.5 min were obtained for iron-free and iron-bound P. chrysogenum siderophore, respectively. The iron-free P. chrysogenum siderophore revealed an exact mass-to-charge ratio (m/z) of 400.46 and iron-bound P. chrysogenum siderophore revealed a m/z of 453.35. The solvent-extracted siderophores inhibited the virulent plant pathogens Ralstonia solanacearum, that causes bacterial wilt in groundnut and Xanthomonas oryzae pv. oryzae which causes bacterial blight disease in rice. Thus, bioactive siderophore-producing endophytic P. chrysogenum can be exploited in the form of formulations for development of resistance against other phytopathogens in crop plants.

Biological and physicochemical properties of cymbidium mosaic virus

The isolated cymbidium mosaic virus (CMV) is one of the most wide-spread and dangerous pathogens that infects promising varieties of orchids. It causes characteristic symptoms on orchid plants, which are manifested in the form of a mosaic. Over time, these areas are necrotized, leading to the stop of flowering the plants and reducing their decorative value. The CyMV is not spread by insects-carriers, but is transmitted by the mechanical inoculation with juice. Electron microscopy revealed flexible filamentous viral particles with a length of about 500 nm. The purified viral preparation is sedimented with a single peak with a sedimentation coefficient of 142S. The floating density of the virus in the preformed CsCl gradient corresponded to 1.3 g/cm3. The electrophoretic analysis of proteins in polyacrylamide gel under denatured conditions showed the presence of two polypeptides with molecular weights of 27 and 31 kDa. RNA CyMV has a molecular weight of 2 · 106 Da. In the translation system of rabbit reticulocytes in vitro, a protein with a molecular weight of about 27 kDa is synthesized. The obtained data allow us to refer CyMV to the group of potexviruses.

Fungal colonization associated with phenological stages of a photosynthetic terrestrial temperate orchid from the Southern Iberian Peninsula.

Fungal endophytes, both mycorrhizal and non-mycorrhizal, are involved in the development of the life cycle of orchids, providing potential beneficial relationships. Here, we assess the succession of changes in the diversity of fungal symbionts associated with a terrestrial temperate orchid species, Anacamptis morio subsp. champagneuxii, over three phenological stages: developed leaves but no stem elongation, flowering, and fruiting. Fungi endophyte associated with roots were obtained by culture in sterile conditions. A total of 18 morphotypes-one Mortierellomycota, two Basidiomycota and 15 Ascomycota-were differentiated, and were also characterized using PCR and DNA sequencing techniques. Only three of the 18 OTUs are shared among the three phenological stages examined: Westerdykella sp., a member of Ceratobasidiaceae, and Fusarium oxysporum, representing a relative abundance of between 28% (fruiting) to 41% (flowering). Our research confirmed that fungal symbionts varied among the different phenological stages examined, the peak of endophyte diversity appearing in the flowering stage. The availability of a diverse mycobiota seems to be important for the survival of orchid plants because it may cover particular physiological needs, and knowledge concerning this mycobiota is of special relevance in the establishment of reliable conservation programmes.

STIMULASI PERTUMBUHAN DAN PERKEMBANGAN PLANLET ANGGREK (Dendrobium sp) PADA TAHAP AKLIMATISASI DENGAN PEMBERIAN VITAMIN B1 DAN ATONIK

Dendrobium sp is a type of orchid that is currently very popularly traded because it has a variety of flower types, but the growth rate is slow. Vitamin B1 (Thiamin) is a micro nutrient that is able to accelerate the division of new cells in the tissue so that it can accelerate the growth of plant vegetative organs. Atonic is a chemical that can stimulate the biochemical and physiological processes of plants, so that atonics is a growth regulator. Atonic is usually used to stimulate the growth of plant roots against nutrients, increase leaf absorption, flower discharge, fruit formation, and increase the number and weight of fruit. The purpose of this study is the Stimulation of Growth and Development of Planlet Orchid (Dendrobium sp) in the Acclimatization Stage by Provision of Vitamin B1 and Atonik.This research was conducted experimentally using a completely randomized design (CRD) with 2 factors, namely the concentration of Vitamin B1 (Thiamin) consisting of 4 treatment groups and Atonic consisting of 4 treatments. Vitamin B1 (0 ml / l, 1.5 ml / l, 3 ml / l, 4.5 ml / l) and Atonik (0 ml / l, 1 ml / l, 2 ml / l, 3 ml / l) and each treatment was repeated 2 times so that 128 plants could each treatment consisting of 4 plants with 4 sample plants. Spraying is done once a week. The parameters observed were percentage growth, plant height, stem diameter, number of leaves, primary root length and number of roots and measured at 2MST.Based on the results of research on Dendrobium sp. Can be concluded 1) Provision of Vitamin B1 significantly affect the growth of orchid plant height (Dendrobium sp). 2) The giving of Atonik significantly influences the growth of the number of leaves, root length and number of roots of orchid plants (Dendrobium sp). 3) Provision of Vitamin B1 and Atonik simultaneously can accelerate to overcome plant height, number of leaves and the budding of orchid plant roots (Dendrobium sp).

Expression regulation of MALATE SYNTHASE involved in glyoxylate cycle during protocorm development in Phalaenopsis aphrodite (Orchidaceae)

Orchid (Orchidaceae) is one of the largest families in angiosperms and presents exceptional diversity in lifestyle. Their unique reproductive characteristics of orchid are attracted by scientist for centuries. One of the synapomorphies of orchid plants is that their seeds do not contain endosperm. Lipids are used as major energy storage in orchid seeds. However, regulation and mobilization of lipid usage during early seedling (protocorm) stage of orchid is not understood. In this study, we compared transcriptomes from developing Phalaenopsis aphrodite protocorms grown on 1/2-strength MS medium with sucrose. The expression of P. aphrodite MALATE SYNTHASE (PaMLS), involved in the glyoxylate cycle, was significantly decreased from 4 days after incubation (DAI) to 7 DAI. On real-time RT-PCR, both P. aphrodite ISOCITRATE LYASE (PaICL) and PaMLS were down-regulated during protocorm development and suppressed by sucrose treatment. In addition, several genes encoding transcription factors regulating PaMLS expression were identified. A gene encoding homeobox transcription factor (named PaHB5) was involved in positive regulation of PaMLS. This study showed that sucrose regulates the glyoxylate cycle during orchid protocorm development in asymbiotic germination and provides new insights into the transcription factors involved in the regulation of malate synthase expression.

Analysis of Decision Support Systems on Recommended Sales of the Best Ornamental Plants by Type

The research objective is to recommend the sale of the best ornamental plant species to lovers of ornamental plants by using decision support system techniques. Ornamental plants are a type of ornamental plants that can survive in various conditions. In this case ornamental plants are also very vulnerable to disease such as root rot, shoot rot and others. Many types of ornamental plant sellers do not know how to handle ornamental plants that have diseases or symptoms when they occur. The study was conducted in Simalungun District with a sample of thirteen traders selling ornamental plants using observation and questionnaire distribution techniques. Selection of ornamental plants based on the types in this study include: Orchid Plants (A1), Tulips (A2), Bougenvil (A3) and Jasmine (A4). The assessment criteria used include: Plant height (C1), Plant quality (C2), Plant type (C3) and Plant age (C4). The method used in this research is Simple Additive Weighting. The results showed that Orchid Plant (A1) was the best alternative for selling ornamental plant species (V1: 0.91) and Jasmine (A4) as a second alternative (V2: 0.8).

Phenotypic traits of Burkholderia spp. associated with ecological adaptation and plant-host interaction

Burkholderia species have different lifestyles establishing mutualist or pathogenic associations with plants and animals. Changes in the ecological behavior of these bacteria may depend on genetic variations in response to niche adaptation. Here, we studied 15 Burkholderia strains isolated from different environments with respect to genetic and phenotypic traits. By Multilocus Sequence Analysis (MLSA) these isolates fell into 6 distinct groups. MLSA clusters did not correlate with strain antibiotic sensitivity, but with the bacterial ability to produce antimicrobial compounds and control orchid necrosis. Further, the B. seminalis strain TC3.4.2R3, a mutualistic bacterium, was inoculated into orchid plants and the interaction with the host was evaluated by analyzing the plant response and the bacterial oxidative stress response in planta. TC3.4.2R3 responded to plant colonization by increasing its own growth rate and by differential gene regulation upon oxidative stress caused by the plant, while reducing the plant's membrane lipid peroxidation. The bacterial responses to oxidative stress were recapitulated by bacterial exposure to the herbicide paraquat. We suggest that the ability of Burkholderia species to successfully establish in the rhizosphere correlates with genetic variation, whereas traits associated with antibiotic resistance are more likely to be categorized as strain specific.

Biodiversity mapping of Dendrobium Sw. section Spathulata Lindl. in the Ramsar Site of Wasur National Park of Indonesia New Guinea

Wasur National Park is a vast area of tropical lowland forest, swamp forest, savannah and wetland in the far south-east corner of Papua-Indonesia. It is bordered by the sea to the south and PNG to the east. It lies within the Trans-Fly region of New Guinea and both the habitat and birds have much in common with northern Australia only 200 km to the south. The site is very seasonal, with both a pronounced wet and dry season. This park displays a tremendous biodiversity of flora and fauna. One prime example of flowering plants is Orchids species. Most orchids in this park resembles to the Australian plants as it share similar vegetation types of heath forest and savanna woodland. Knowledge of orchid diversity from this park is poorly acknowledged. This preliminary study aims to document species diversity, to map diversity and distribution of orchid species of Dendrobium section Spatulata and the host plants in the national parks. The study is conducted in six sites i.e. Bokem, Sota, Rawa Dongami, Rawa Biru, Wasur village, and Yanggandur. The plants were collected and recorded whenever they are encountered on the host trees. In total 40 orchid plants are collected and identified using bio-molecular techniques combined with morphological characters. 11 species recorded from Dendrobium section Spathulata i.e. Dendrobium canaliculatum, Dendrobium carronii, Dendrobium d’albertisii, Dendrobium devosianum, Dendrobium discolor, Dendrobium ionoglossum, Dendrobium johannis, Dendrobium nindii, Dendrobium semifuscum, Dendrobium sylvanum and Dendrobium trilamellatum. Other species from Dendrobium section Phalaenanthe such as Dendrobium bigibum, Dendrobium section Calyptrochilus i.e. Dendrobium smilliae dan Dendrobium capituliferum, Dendrobium section Dendrocorynae, and one species of Pomatocalpa marsupiale. During the field observation, we noticed hunting activity run by vendors and hunters. This activity brings impact to the sustainability of the plants. Vendors are mainly locals who inhabit and land tenure in this park.

PENGARUH PEMBERIAN HORMON NAA, PUPUK GANDASIL DAN PUPUK GROWMORE PADA PERTUMBUHAN TANAMAN ANGGREK

Orchid is an ornamental plant, including the Orchidaceae tribe, which is widely favored among the ornamental plant community because it has high economic value, unique shapes, attractive colors and longer-lasting blooming flowers, one of which is a Phalaenopsis orchid. One of the efforts to accelerate the vegetative phalaenopsis can be done with the application of the NAA hormone and leaf fertilizers such as Gandasil fertilizer and Growmore fertilizer. The aims of this research to determine the effect of NAA, Gandasil and Growmore fertilizer types on the growth of hybrid Phalaenopsis orchids. The study was conducted at Greenhouse Jalan Tlogomas Kec. Lowokwaru, Malang City, for 5 months. The experiment was carried out using a factorial Completely Randomized Design (CRD) consisting of 2 factors namely, the factor I: NAA concentration: control 0 ppm (N0), 100 ppm (N1), 200 ppm (N2), and 300 ppm (N3). Factor II: leaf fertilizer, Growmore (P1) and Gandasil D (P2). Variables observed included: when buds appeared, leaf length, leaf width and percentage of live plants. The results showed that there was an interaction between the concentration of NAA and the type of leaf fertilizer on the emergence of shoots. When the fastest shoots appear at 100 ppm NAA, Growmore fertilizer (N1P1), which is 29 days. The NAA hormone influences the increase in leaf length and leaf width until 16 weeks of age. The best growth of hybrid Phalaenopsis was obtained at the administration of 200 ppm NAA with an increase in leaf length of 1.49 cm and an increase in leaf width of 1.06 cm until 16 weeks of age. Growmore and Gandasil D did not affect the vegetative growth of hybrid Phalaenopsis Orchid plants.

Genome-wide identification and expression profiling of SET DOMAIN GROUP family in Dendrobium catenatum

BackgroundDendrobium catenatum, as a precious Chinese herbal medicine, is an epiphytic orchid plant, which grows on the trunks and cliffs and often faces up to diverse environmental stresses. SET DOMAIN GROUP (SDG) proteins act as histone lysine methyltransferases, which are involved in pleiotropic developmental events and stress responses through modifying chromatin structure and regulating gene transcription, but their roles in D. catenatum are unknown.ResultsIn this study, we identified 44 SDG proteins from D. catenatum genome. Subsequently, comprehensive analyses related to gene structure, protein domain organization, and phylogenetic relationship were performed to evaluate these D. catenatum SDG (DcSDG) proteins, along with the well-investigated homologs from the model plants Arabidopsis thaliana and Oryza sativa as well as the newly characterized 42 SDG proteins from a closely related orchid plant Phalaenopsis equestris. We showed DcSDG proteins can be grouped into eight distinct classes (I~VII and M), mostly consistent with the previous description. Based on the catalytic substrates of the reported SDG members mainly in Arabidopsis, Class I (E(z)-Like) is predicted to account for the deposition of H3K27me2/3, Class II (Ash-like) for H3K36me, Class III (Trx/ATX-like) for H3K4me2/3, Class M (ATXR3/7) for H3K4me, Class IV (Su (var)-like) for H3K27me1, Class V (Suv-like) for H3K9me, as well as class VI (S-ET) and class VII (RBCMT) for methylation of both histone and non-histone proteins. RNA-seq derived expression profiling showed that DcSDG proteins usually displayed wide but distinguished expressions in different tissues and organs. Finally, environmental stresses examination showed the expressions of DcASHR3, DcSUVR3, DcATXR4, DcATXR5b, and DcSDG49 are closely associated with drought-recovery treatment, the expression of DcSUVH5a, DcATXR5a and DcSUVR14a are significantly influenced by low temperature, and even 61% DcSDG genes are in response to heat shock.ConclusionsThis study systematically identifies and classifies SDG genes in orchid plant D. catenatum, indicates their functional divergence during the evolution, and discovers their broad roles in the developmental programs and stress responses. These results provide constructive clues for further functional investigation and epigenetic mechanism dissection of SET-containing proteins in orchids.

THE ANTIMICROBIAL ACTIVITY OF ETHANOLIC EXTRACTS DERIVED FROM LEAVES AND PSEUDOBULBS OF COELOGYNE FLACCIDA LINDL. (ORCHIDACEAE) AGAINST DIFFERENT STAPHYLOCOCCUS AUREUSSTRAINS

The present study was conducted to investigate in vitro antimicrobial activity of ethanolic extracts obtained from leaves and pseudobulbsof Coelogyneflaccida against Staphylococcus aureus subsp. aureus Rosenbach (ATCC®25923™) (mecA negative), Staphylococcus aureus subsp. aureus Rosenbach (ATCC®29213™)(mecA negative, Oxacillin sensitive, weak β-lactamase-producing strain), Staphylococcus aureus NCTC 12493 (mecA positive, Methicillin-resistant, EUCAST QC strain for cefoxitin).The antimicrobial susceptibility testing was done on Muller-Hinton agar by the disc diffusion method (Kirby-Bauer disk diffusion susceptibility test protocol). The leaves and pseudobulbs of C. flaccida plants, cultivated under glasshouse conditions, were sampled at M.M. Gryshko National Botanic Garden (NBG), National Academy of Science of Ukraine. Freshly leaves and pseudobulbs were washed, weighed, crushed, and homogenized in 96% ethanol (in proportion 1:19) at room temperature. The extracts were then filtered and investigated for their antimicrobial activity. The cultivation medium was trypticase soy agar (Oxoid™, UK), supplemented with 10% defibrinated sheep blood. Cultures were grown aerobically for 24 h at 37°C. The cultures were later diluted with a sterile solution of 0.9% normal saline to approximate the density of 0.5 McFarland standard. The McFarland standard was prepared by inoculating colonies of the bacterial test strain in sterile saline and adjusting the cell density to the specified concentration. The examined ethanolic extracts obtained from leaves and pseudobulbs of C. flaccida showed remarkable antibacterial activities against different S. aureusstrains. The observed activity may contribute to the reasons why orchids are used for infectious and inflammatory conditions in ethnomedicine. The research showed that ethanolic extracts of C. flaccida possess the highest antibacterial potency against S. aureus NCTC 12493 strain. These findings led the authors to suggest that these extracts may be used as natural antiseptics and antimicrobial agents in medicine and veterinary practice. Nevertheless, despite the promising results, more research should be carried out to further evaluate the roles of particular compounds, isolated from all parts of orchid plants, attributable to antimicrobial activity.

UTILIZATION OF DRYING AIR TEMPERATURE AND RELATIVE HUMIDITY FOR SAVING THE REQUIRED TIME AND ENERGY FOR DRYING ROSEMARY PLANTS

The purpose of this study is to test and evaluate the effect of drying temperature on the behavior of moisture content and relative humidity of the drying air and drying time of orchid plants at four different levels of temperature. An experimental dryer was designed and installed with local components, which can control the temperature under study to the levels of (35, 40 , 45 and 50 oC) with a corresponding relative humidity of to the levels of (32.2, 28.3, 24.5 and21.2) respectively. The air speed was adjusted at (1.5 m / s) to achieve maximum utilization of energy used in drying. The average primary moisture content of the rosemary was 80% on a wet basis. There is an inverse relationship between the temperature and relative humidity of the air inside the dryer where the relative humidity of the air decreases from 32.2% to 21.2% when the temperature increased from 35 to 50 oC . There is an inverse relationship between temperature and final moisture content values ​​where the final moisture content is reduced from 80 to 32.65% on a dry basis with temperatures increasing from 35 to 50 ° C. There is a difference between the temperature in and out of the drying air and the difference is greater at the beginning of the drying process has decreased to reach the lowest value at the end of the drying process. The highest value of the relative humidity outside of the air was at the beginning of the drying process and it was reduced during the drying process until it reaches its lowest value at the end of the drying process. There is an inverse relation between temperature and drying time, the higher the temperature the lower the drying time.

Protecting small populations of rare species. Case study on Dactylorhiza viridis (Orchidaceae) in Fancott Woods and Meadows SSSI, Bedfordshire, UK

Dactylorhiza viridis is a small orchid species, sensitive to competition with dense and tall herbaceous vegetation. Its populations in Europe and in the UK have been declining over the last century. Small, isolated populations have remained in Protected Areas. The population of the species in Fancott Woods and Meadows Site of Special Scientific Interest (SSSI) was studied in 2011–2019. The number of orchid plants varies substantially from year to year, but the areas occupied by the population remain the same. Fruit production is high. The population is under threat from herbivores and from competition with tall vegetation on the meadow. Expansion of the vigorous herb Filipendula ulmaria was recorded on the meadow in 2009 that negatively affected the rare plant community. Additional management of an early hay cut was implemented on the meadow as a trial. A botanical survey of managed and control plots showed a reduction in the vigorous herbs, an increase in species number in the cut plots and a resulting more open sward. The orchid population also benefits from a more open sward. The management of the site is the key to the survival of this small orchid population.

PENGARUH PUPUK DAUN GROWMORE DAN HYPONEX TERHADAP PERTUMBUHAN PLANLET DENDROBIUM DIAN AGRIHORTI SECARA IN VITRO

ABSTRACT Orchid plants are one of the ornamental plant commodities that have no food reserves in their seeds and have very fine and small seed sizes making it difficult to propagate naturally. One alternative for the propagation of this plant is to carry out vegetative propagation in vitro or tissue culture. The success of plant tissue culture can not be separated from the role of media composition used. Leaf fertilizer is one of the alternative media that can be used as media material in orchid plant tissue culture because leaf fertilizers contain macro and micro nutrients that can provide nutrient intake to explants to support the growth and development of these explants. Propagation of Dian Agrihorti Dendrobium orchid plant in vitro through callus proliferation using different brands of leaf fertilizer media namely leaf fertilizer hyponex brand and growmore brand. The results of the observation showed that the most proliferative Embryogenic Callus and Proliferation Rate were produced from the treatment of adding 4 ppm growmore, namely 88.42% and 322.41%. For the best color callus parameters generated from the control treatment.

Molecular Identification of Several Orchid Species Based on OPA10 and OPA18 RAPD Marker

The purpose of this study was to determine the genetic characteristics of nine orchids plants collected by Biology Gardens of Mathematics and Science Faculty of UNY based on OPA10 and OPA18 markers, to detect their genetic relationship, and determining the exact RAPD markers for identification of intraspecies and interspecies orchids. The analysis was carried out by isolating DNA from the leaves of 9 species of orchids (Rhynchostylis retusa, Vanda tricolor, Dendrobium aphyllum, Dendrobium fimbriatum, Dendrobium moschatum, Dendrobium crumenatum, Dendrobium antennatum, Dendrobium anosmum Gigantea Alba and Dendrobium anosmum Gigantea) using TIANGEN DNA healing plant kit. Molecular identification was analysed based on the PCR-RAPD technique using OPA 10 and OPA18 primers. Electrophoregraph of PCR results are converted into binary data and analysed with NTSYSpc 2.02 software. The similarity index (kinship level) was analysed based on UPGMA dendrogram. The results of the analysis showed that there was genetic diversity in 9 orchid plants tested. Intra-species orchids show higher similarity than inter-species. Primer OPA 10, OPA18, and a combination of both shows polymorphism in intra-species orchids.

Developing audio-visual learning media based on video documentary on tissue culture explant of Dendrobium bigibbum

The development of science and technology challenge teachers to pay a great effort in creating an effective media. The aim of this study was to produce audio-visual learning media based on video documentary explanation of orchid plants (Dendrobium bigibbum) on tissue culture material. This research was conducted on July 2019. This R&D used the ADDIE model without implementation phase. The data collection instruments used were validation sheets and student questionnaire responses. The data obtained were analyzed using percentage. The evaluation results of the audiovisual learning media based on video documentary tissue culture showed that it was considered as very feasible to be used with an average percentage score of 87.50% by tissue culture expert, 91,87% by learning media expert, 91.66% by the teachers, and 94.37% by the students. The effectiveness of the learning media developed need to be ensured by conducting the implementation phase.

Phalaenopsis LEAFY COTYLEDON1-Induced Somatic Embryonic Structures Are Morphologically Distinct From Protocorm-Like Bodies.

Somatic embryogenesis is commonly used for clonal propagation of a wide variety of plant species. Induction of protocorm-like-bodies (PLBs), which are capable of developing into individual plants, is a routine tissue culture-based practice for micropropagation of orchid plants. Even though PLBs are often regarded as somatic embryos, our recent study provides molecular evidence to argue that PLBs are not derived from somatic embryogenesis. Here, we report and characterize the somatic embryonic tissues induced by Phalaenopsis aphrodite LEAFY COTYLEDON1 (PaLEC1) in Phalaenopsis equestris. We found that PaLEC1-induced somatic tissues are morphologically different from PLBs, supporting our molecular study that PLBs are not of somatic embryonic origin. The embryonic identity of PaLEC1-induced embryonic tissues was confirmed by expression of the embryonic-specific transcription factors FUSCA3 (FUS3) and ABSCISIC ACID INSENSITIVE3 (ABI3), and seed storage proteins 7S GLOBULIN and OLEOSIN. Moreover, PaLEC1-GFP protein was found to be associated with the Pa7S-1 and PaFUS3 promoters containing the CCAAT element, supporting that PaLEC1 directly regulates embryo-specific processes to activate the somatic embryonic program in P. equestris. Despite diverse embryonic structures, PaLEC1-GFP-induced embryonic structures are pluripotent and capable of generating new shoots. Our study resolves the long-term debate on the developmental identity of PLB and suggests that somatic embryogenesis may be a useful approach to clonally propagate orchid seedlings.

Biological role of mycorrhizal fungi on the assimilation and transportation of carbon and nitrogen to Anacamptis palustris and Anacamptis laxiflor.

Fungal is a physiological trail and its understanding in the assimilation with the transfer of carbon (C) cum nitrogen (N) or (C/N) to orchid-seedlings have not been determined. Labelled stable isotopes 13C and 15N were used to plan the flow of C and N between orchid plants and mycorrhizal connotations in-terms of bulk transfer for C/N. This study attends to comprehend the mechanism, supporting mycorrhizal fungi which influences on orchid-seedling growth. Determined integration and transfer of C/N from amino acids (AA), ammonium nitrate (NH4NO3) and sugar for orchid-plant may lead to understand these mechanisms. This current study tries to estimate the importance of organic compounds as a source for C/N over the inorganic-NH4NO3. Generally, after begging of germination and when it is found to be associated to the nutrient resource, organic compound enhance the biomass accumulation of two orchid species. AA significantly increase the mass of 13C assimilated by two species. With amino acids the concentration of 13C in two species was greater than with NH4NO3 and sugar. At another phase, amount of 15N content shoots was a higher value in Anacamptis laxiflora shoots assimilated substantially additional of 15N with NH4NO3 plus sugar compared with ammonium nitrate only. This study showed that two terrestrial orchids species are reliant on organic compounds as a source of carbon and nitrogen more than inorganic compounds.

Alternaria alternata Causing Leaf Spot on Dendrobium candidum in Anhui Province, China

Dendrobium candidum is an orchid plant commonly used in traditional Chinese medicine due to its antitumor and antiaging effects, as well as the enhancement of human body immunity. During May 2019, an estimated 20% of D. candidum plants were observed with leaf spots in the greenhouse in Ningguo, Anhui Province, China. The initial disease symptoms appeared as small brown to black spots on the leaves and then gradually expanded to form circular or elliptical gray-white necrotic lesions. As the disease progressed, the lesions dried out and were easily perforated. To identify possible pathogens, symptomatic plant leaves were collected, and 15 small pieces of tissue taken from the margins of lesions were surface sterilized in 70% ethanol for 30 s followed by 0.1% HgCl solution for 1 min, rinsed two times with sterilized distilled water, placed on potato dextrose agar (PDA) amended with 150 μg/ml of cefotaxime sodium salt, and incubated at 28°C for 2 to 3 days in the dark. Eleven fungal colonies with identical morphological characteristics were isolated from all diseased tissues, and four single-spore isolates were randomly selected for morphological and molecular analysis. All isolates developed olivaceous colonies with white borders on PDA. Conidia were brown, oval to fusiform, two to six transverse and zero to three longitudinal septa, approximately 15.27 to 35.27 × 11.08 to 19.09 μm (n = 54). Most conidia had a conical beak, 5.45 to 32.72 μm in length and 3.27 to 3.98 μm in width. The morphology is similar to the descriptions of Alternaria spp. (Simmons 1971). The internal transcribed spacer region, partial sequence of the β-tubulin gene (TUB2), RNA polymerase II beta subunit (RPB2), glyceraldehyde-3-phosphate dehydrogenase (gapdh), and Alternaria major allergen (Alt a1) gene of the four isolates were amplified and sequenced using primers ITS1/ITS4 (White et al. 1990), T1/T2 (O’Donnell and Cigelnik 1997), RPB2DF/RPB2DR (Lawrence et al. 2013), GDF/GDR (Templeton et al. 1992), and Alt-for/Alt-rev (Hong et al. 2005), respectively. Sequences of the five loci from the representative isolate NSH-1 were deposited in GenBank (accession nos. MN173832, MN175551, MN307738, MN307737, and MN313882) and shared >99% nucleotide identity with the corresponding sequences (KU324792, MK050502, MG736307, MK210169, and MG199093) of the reference isolates of Alternaria alternata in GenBank, respectively. Based on morphological and molecular studies, these isolates were identified as A. alternata. To test pathogenicity, a conidial suspension (1 × 10⁶ spores/ml) prepared from a 10-day-old culture of NSH-1 was sprayed (1 ml per plant) on six 12-month-old D. candidum seedlings. Control plants (six plant replicates) were treated with sterile water. The inoculated plants were incubated in a growth chamber at 25 ± 0.5°C under moist conditions (relative humidity = 90 ± 5%). After 2 weeks, 85% of the seedlings inoculated with A. alternata had black spots and necrotic lesions on the leaves, but control plants were asymptomatic. A. alternata was reisolated from the necrotic lesions on inoculated plants. To our knowledge, this is the first report of A. alternata causing leaf spot disease on D. candidum in Ningguo, Anhui Province of China. A. alternata infections threaten the production of D. candidum; thus, this report will accelerate the establishment of effective control strategies to this disease.

Conservation of Schomburgkia crispa Lindl. (Orchidaceae) by reintroduction into a fragment of the Brazilian Cerrado

Asymbiotic germination of native orchids is an important technique for producing seedlings for use in species reintroduction programs, as it facilitates the maintenance of genetic variability. The objective of this study was to evaluate the adaptive responses of Schomburgkia crispa Lindl. (Orchidaceae) in an area undergoing environmental restoration, and to compare the efficacy of traditional and alternative substrates in order to contribute to the management and reintroduction of this species. Plants of S. crispa were obtained from asymbiotic sowing, and acclimated plants (ACP) were reintroduced in an underbrush area at the State University of Mato Grosso do Sul using three planting treatments: without substrate (WS); buriti stem substrate (BU); and, coconut fiber substrate (CF). Stress was assessed based on chlorophyll a fluorescence measurements and infrared thermography, and the growth environment was evaluated for light conditions and canopy cover. A completely randomized design was used with three treatments, each consisting of one substrate, with 10 single-plant replicates. After 850 days, fluorescence and survival of established plants (ESP) were re-evaluated. At 21 days after reintroduction, the plants showed 100% survival regardless of the substrate used, these values reached 73.3% for ESP plants. The largest variations between the temperature of the phorophytes and the temperature of the epiphytic orchid plants occurred on the day of reintroduction. There was no significant difference in the potential quantum efficiency of photosystem II (PSII: Fv/Fm) among treatments for ACP plants showed lower values of potential quantum efficiency (Fv/F0) to WS. Although the different substrates until 21 days did not significantly affect plant survival, temperature, or the photochemical efficiency of PSII, when ACP and ESP plants were compared, the quantum efficiency were significantly higher to acclimated plants indicating the better adjustment of the photosynthetic apparatus after 850 days justifying the high survival percentage. These data highlight the ability of S. crispa to resist in a heterogeneous light environment even through coming from asymbiotic sowing.