92 research outputs found
Effect of different substrates on in vitro symbiotic seed germination for soilless production of Anacamptis laxiflora orchid
In recent years, the orchid species have become endangered due to overuse and habitat destruction. As with most flowering plants, seed production is the primary strategy for reproduction in orchids. Orchids produce tiny seeds consisting of a seed coat and a rudimentary embryo. However, it lacks the endosperm, which is generally required as the primary energy source during germination. The only way to germinate orchid seeds is to get nutrients from an external source. In nature, this is achieved by mycorrhizal symbiosis. This study used Ceratobasidium sp. inoculation of Anacamptis laxiflora (Lam.) seeds combined with media with various organic substrates to determine their effectiveness on germination and seedling development by in vitro culture. The highest germination rate (35.78%) was obtained in the medium with addition of young hazelnut leaves. Then, soilless ex vitro symbiotic germination was performed on young hazelnut leaves, the most effective organic substrate. Seed germination was determined to be 19.01% in this medium while 14.87% seedlings with developed leaves and roots were formed. For the first time, success was achieved by producing A. laxiflora from seed in ex vitro conditions without soil and adapting it to nature
Fungal diversity and ex vitro symbiotic germination of Serapias vomeracea (Orchidaceae)
Conservation of orchids can be possible with effective seed germination and seedling growth methods. In this context, ex vitro symbiotic seed germination and seedling growth of orchid seeds may be convenient and advantageous. In this study, both the diversity of the root endophytic fungi in Serapias vomeracea (Burm.f.) Briq. and the ex vitro effects of these fungi on seed germination, seedling development and tuber formation were revealed. The fungi were isolated monthly for two years from S. vomeracea roots and the isolates were identified based on morphological characters and internal transcribed spacer (ITS) region of nuclear ribosomal DNA (rDNA) sequences. All of the Rhizoctonia-like isolates that joined the mycorrhizal association were closely related to Tulasnella calospora (thirty isolates). Non-Rhizoctonia isolates are closely related to Fusarium tricinctum (two isolates), Aspergillus spelaeus (one isolate) and Talaromyces pinophilus (Pezizales) (one isolate). The viability rate of the seeds was 90.32%. The seed packs were placed in soils containing fungus and the germination process was followed. All isolates associated with Tulasnella calospora promoted germination and seedling development. Isolate Svl 21 (Tulasnella sp.) was found to have the highest germination rate (98%) but isolate Svl 4 developed seedlings with advanced leaves (stage 4 (S4): seedlings with advanced leaves and/or rooted, 13.67%). All seedlings at S4 were transferred to the natural environment; the first tubers were observed seven months after. In this study, for the first time, a tuberous European orchid, S. vomeracea developed from seed to adult plant in a natural environment
Mycorrhizal fungi diversity of Serapias orientalis
Orkideler, yumrularının aşırı toplanması ve habitatlarının ciddi şekilde tahrip olması sonucu yok olma
tehdidi altındadır. Doğada orkidelerin korunması mikorizal fungus biyolojik çeşitliliğinin varlığına
bağlıdır. Bu çalışmada, Orta ve Doğu Karadeniz bölgesinde 4 ilin (Samsun, Ordu, Giresun, Trabzon)
sınırları içinde farklı habitatlardan toplanan Serapias orieantalis (Greuter ) Bauman H, Künkele
köklerindeki mikorizal fungusların moleküler tanımlaması yapılmıştır. Bitki kökleri 2015 bahar
aylarında toplanmış ve önce mikroskopta incelenerek mikorizal funguslar izole edilmiştir. Saflaştırılan
izolatlar, koloni özellikleri (koloni tipi, koloni rengi), hif yapısı (hif çapı ve dallanma yapısı) ve çekirdek
sayılarının belirlenmesi amacıyla PDA (patates dektroz agar) ortamında geliştirilmiştir. İzolatları
morfolojik özelliklerine göre gruplandırmak için küme analizi (UPGMA) yöntemi uygulanmış ve
kladogram oluşturulmuştur. Kümeleme analizine göre oluşturulan 3 grubun izolatlarını moleküler
düzeyde tanımlayabilmek için ITS-1 ve ITS-4 primerleri kullanılarak nüklear ribozomal DNA (rDNA)’nın
ITS1-5.8S-ITS2 gen bölgesi çoğaltılmıştır. DNA dizilimine dayanarak, 13 Rhizoctonia benzeri izolatın
Tulasnella cinsi ile 2 Rhizoctonia benzeri olmayan izolatın Fusarium oxysporum Schltdl. türü ile yakın
ilişkili olduğu bulunmuştur.Orchids are under a serious threat of extinction as a result of both excessive collecting and severe
destruction of their habitats. Studies conducted have shown that the protection of orchids depends on
the presence of mycorrhizal fungal biodiversity. In this study, molecular identification of mychorrhizal
fungi of Serapias orieantalis roots taken from different habitats within the borders of 4 provinces
(Samsun, Ordu, Giresun, Trabzon) in the Central and Eastern Black Sea region was conducted. Plant
roots were collected in the spring of 2015 and first examined under a microscope and then mycorrhizal
fungi were isolated. Purified isolates were developed in PDA (potato dectrose agar) medium in order
to determine colony characteristics (colony type, colony color), hif structure (hif diameter and
branching structure) and core numbers. Cluster analysis (UPGMA) method was applied to group the
isolates according to their morphological characteristics and a cladogram was created. Nuclear
ribozomal DNA (rDNA)’nın ITS 1-5.8S-ITS 2 gene region was amplified using ITS 1/ITS 4 primers in order
to identify isolates of 3 groups formed according to morphological data at the molecular level. Based
on the DNA sequence, 13 Rhizoctonia-like isolates were closely related to the Tulasnella genus, and 2
Rhizoctonia-unlike isolates were closely related to the Fusarium oxysporum
Functionalized Mesoporous SBA-15 with CeF3: Eu3+ Nanoparticle by Three Different Methods: Synthesis, Characterization, and Photoluminescence
Luminescence functionalization of the ordered mesoporous SBA-15 silica is realized by depositing a CeF3: Eu3+ phosphor layer on its surface (denoted as CeF3: Eu3+/SBA-15/IS, CeF3: Eu3+/SBA-15/SI and CeF3: Eu3+/SBA-15/SS) using three different methods, which are reaction in situ (I-S), solution impregnation (S-I) and solid phase grinding synthesis (S-S), respectively. The structure, morphology, porosity, and optical properties of the materials are well characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, N2 adsorption, and photoluminescence spectra. These materials all have high surface area, uniformity in the mesostructure and crystallinity. As expected, the pore volume, surface area, and pore size of SBA-15 decrease in sequence after deposition of the CeF3: Eu3+ nanophosphors. Furthermore, the efficient energy transfer in mesoporous material mainly occurs between the Ce3+ and the central Eu3+ ion. They show the characteristic emission of Ce3+ 5d → 4f (200–320 nm) and Eu3+5D0 → 7FJ(J = 1–4, with 5D0 → 7F1 orange emission at 588 nm as the strongest one) transitions, respectively. In addition, for comparison, the mesoporous material CeF3: Eu3+/SBA-15/SS exhibits the characteristic emission of Eu3+ ion under UV irradiation with higher luminescence intensity than the other materials
A multiwavelength study of the massive star forming region IRAS 06055+2039 (RAFGL 5179)
We present a multiwavelength study of the massive star forming region
associated with IRAS 06055+2039 which reveals an interesting scenario of this
complex where regions are at different stages of evolution of star formation.
Narrow band near-infrared (NIR) observations were carried out with UKIRT-UFTI
in molecular hydrogen and Br lines to trace the shocked and ionized
gases respectively. We have used 2MASS data to study the nature of
the embedded cluster associated with IRAS 06055+2039. We obtain a power-law
slope of 0.430.09 for the -band Luminosity Function (KLF) which is
in good agreement with other young embedded clusters. We estimate an age of 2
-- 3 Myr for this cluster. The radio emission from the ionized gas has been
mapped at 610 and 1280 MHz using the Giant Metrewave Radio Telescope (GMRT),
India. Apart from the diffuse emission, the high resolution 1280 MHz map also
shows the presence of several discrete sources which possibly represent high
density clumps. The morphology of shocked molecular hydrogen forms an arc
towards the N-E of the central IRAS point source and envelopes the radio
emission. Submillimetre emission using JCMT-SCUBA show the presence of a dense
cloud core which is probably at an earlier evolutionary stage compared to the
ionized region with shocked molecular gas lying in between the two. Emission
from warm dust and the Unidentified Infrared Bands (UIBs) have been estimated
using the mid-infrared (8 -- 21 m) data from the MSX survey. From the
submillimetre emission at 450 and 850 m the total mass of the cloud is
estimated to be 7000 -- 9000 .Comment: Accepted for publication in A &
A comparative study of co-precipitation and sol-gel synthetic approaches to fabricate cerium-substituted Mg Al layered double hydroxides with luminescence properties
Mg/Al/Ce layered double hydroxides (LDHs) intercalated with carbonate and hydroxide anions were synthesized using co-precipitation and sol-gel method. The obtained materials were characterized by thermogravimetric (TG) analysis, X-ray diffraction (XRD) analysis, fluorescence spectroscopy (FLS) and scanning electron microscopy (SEM). The chemical composition, microstructure and luminescent properties of these LDHs were investigated and discussed. The Ce3 + substitution effects were investigated in the Mg3Al1 − xCex LDHs by changing the Ce3 + concentration in the metal cation layers from 0.05 to 10 mol%. It was demonstrated, that luminescence properties of cerium-substituted LDHs depend on the morphological features of the host lattice.publishe
Ex vitro symbiotic germination of the seeds of Anacamptis coriophora (L.) R.M. Bateman, Pritgeon & M.W. Chase and Orchis anatolica Boiss
Rapid destruction of orchid habitats and over-collection of the tubers are the greatest threats to orchid diversity. To counter these threats, it is necessary to grow orchid tubers easily and quickly for economic reasons and to reintroduce populations in the habitats of species that are facing extinction. This study demonstrates a simple viability test for orchid seeds and the ex vitro symbiotic seed germination of temperate orchids. Viability of the seeds of two orchid species, Anacamptis coriophora and Orchis anatolica, was determined without any chemical treatment of the seed coat. Seeds were incubated in packs in moist cocopeats for five days during which seed viability tests being performed daily. The highest viability rate was found in the seeds that were incubated for five days (64.33% for O. coriophora; 67.19% for O. anatolica). The seeds of these orchids were sown non-axenically into a pre-inoculated soil mixture with a compatible fungus, Ceratobasidium sp. AG A. The seeds of both the orchids germinated 18 days after sowing. Leafy and rooted seedlings developed two months after sowing and the first tubers of both the species developed seven months later
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