Yazar "Hürkan, Kaan" seçeneğine göre listele

Listeleniyor 1 - 8 / 8
  • [ X ]
    Öğe
    COMPARATIVE GROWTH MEDIA PERFORMANCES ON IN VITRO PROPAGATION OF SOME SALEP ORCHIDS
    (2018) Hürkan, Yasemin Kemeç; Hürkan, Kaan; Akı, Cüneyt
    Due to the increasing demand and over-collection of orchids from nature to produce salep, scientists have been led to search for more efficient ways to propagate these specific orchids in vitro. This present study compares germination performances of two commercial (Orchimax and Knudson C) and one specially prepared orchid growth media (SV) on economically and medicinally important orchids used to make salep; Anacamptis pyramidalis (L.) L.C. Rich, Anacamptis morio (L.) R.M. Bateman, Pridgeon & M.W. Chase subsp. morio, Dactylorhiza romana (seb.) Soo, Neotinea tridentata (Scop.) R.M. Bateman, Pridgeon & M.W. Chase and further aims to obtain a mature orchid plant by following the natural environmental cycle.Significant differences in seed germination and protocorm development were observed. Asymbiotic germination tests showed that the specially prepared growth media performed better than the commercial media by 79.11% germination rate. Also, that A. morio subsp. morio had the best germination rate by 88.91%. Protocorms developed in the sixteenth week after sowing. Soil was collected from the natural habitat of each species and was used as a potting substrate, and this helped orchids to pass their initial acclimatization stage. Regeneration success of orchids for in vitro conditions could be increased by using SV growth medium, following their natural seasonal cycle and using specific substrates from their respective habitats
  • [ X ]
    Öğe
    DETERMINATION OF TOTAL PHENOLIC AND FLAVONOID CONTENTS, ANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES OF SOME IMPORTANT SALEP ORCHIDS
    (2019) Hürkan, Kaan; Yüksel, Merve Ballı; Hürkan, Yasemin Kemeç; Manav, Neslihan Demir
    In this study we evaluated the secondary metabolites, total phenolic (TPC) and flavonoid contents (TFC), antioxidant andantimicrobial activities of salep orchids, Anacamptis morio, Anacamptis pyramidalis, Neotinea tridentata, Ophrys mammosa,Ophrys lutea, and Ophrys speculum. DPPH free radical scavenging assay was used to determine the antioxidant activities ofn-hexane, chloroform, methanol and water extracts of the plants. The antimicrobial activities were also determined by the Brothmicro-dilution method. The extracts were studied for antimicrobial activity by the Minimum Inhibitory Concentration (MIC)approach against seven clinical pathogenic bacteria and two fungi. Phytochemical screening revealed that the presences ofcoumarins, flavonoids, flavanones, cardiac glycosides, proteins and quinones. The extracts had variable TPC and TFC, withvalues of 4.46 ± 0.19–45.83 ± 1.86 mg gallic acid equivalent/g dry weight and 0.67 ± 0.04–8.64 ± 0.37 mg quercetinequivalent/g dry weight respectively. O. speculum had the highest (35.12%) antioxidant activity, followed by O. mammosa(33.17%). Chloroform extracts of all species showed significant antioxidant and antimicrobial activity. These bioactivities ofthe chloroform extracts were positively associated with the total phenolic and flavonoid contents. The MIC concentrationsranged from 0.156–20 mg/mL. The present investigation shows that the extracts of these species, especially chloroformextracts, could be used as potential antioxidant and antimicrobial sources.
  • [ X ]
    Öğe
    Identification of reference genes for real-time quantitative polymerase chain reaction based gene expression studies on various Olive (Olea europaea L.) tissues
    (Taylor & Francis Ltd, 2018) Hürkan, Kaan; Sezer, Fatih; Özbilen, Aslıhan; Taşkın, Kemal Melih
    Reference genes are essential for the normalisation of the expression data of quantitative real-time PCR for the purposes of validation. Although several reference genes have been validated for the olive, comprehensive analyses including an excessive number of candidate reference genes still require study in various olive tissue samples. In this work, a total of 40 candidate reference genes were tested for their stability in 8 different olive tissues (root, apical bud, lateral bud, pedicel, young leaf, mature leaf, fruit mesocarp, and seed) with the utilisation of the most popular software programs including GeNorm, NormFinder, BestKeeper, and Delta C-t. The analyses of expression stability of candidate reference genes using quantitative real-time PCR demonstrated ubiquitin-conjugating enzyme (UBC1) as the most stable reference gene for the studied tissues of the olive. The GeNorm software also calculated the optimum reference gene combinations as two which consist of UBC1 and the Clathrin adaptor complex medium subunit (CLATHRIN) genes. This study provides the most stable reference gene combination for normalisation of target genes for quantitative real-time PCR gene expression studies on the olive.
  • [ X ]
    Öğe
    In vitro pollen germination of orchids traditionally used to produce salep
    (Charles University in Prague, 2015) Kemeç, Yasemin; Hürkan, Kaan; Aki, Cüneyt
    In Turkey the tubers of about 120 orchid species are widely collected for manufacturing the traditional drink salep. In this study, we focused on the in vitro germination of the pollen of the salep orchid species Ophrys mammosa, Orchis provincialis, Anacamptis morio subsp. morio, Orchis simia and Neotinea tridentata and discussed the potential effects this might have on the conservation of these orchids by reducing the need to collect them in the field. Pollen was sown on different media; Knudson, Orchimax and the medium described by Malmgren, and then incubated at 24 ± 1 °C in darkness for 24 h. Germinated pollen was stained with Brilliant Blue and examined under a stereoscopic microscope. Results of Tukey and Dunnett T3 statistical tests indicated that in terms of percentage germination, the best germination was observed on O. mammosa by 55% and Orchimax was the most successful medium by 50.5%. For pollinaria germination, the best rate was observed on O. mammosa by 69%. The medium Malmgren was the best germinative by 61.3%. It is clearly seen that difference in germination rates among studied species are achieved using different media. The development of such a method of studied species in this research points to the fact that this is possible and should serve as encouragement for others to devise procedures for other species. These kinds of researches on propagation of orchids would be useful to reintroducing some of the rarer, endangered and endemic species in Turkey such previously succeed for Orchis militaris and Liparis loeselii in Great Britain.
  • Küçük Resim
    Öğe
    Internal Transcribed Spacer (ITS) Fails Barcoding of the Genus Neotinea Rchb.f. (Orchidaceae)
    (Ankara University, 2021) Hürkan, Kaan; Taşkın, Kemal Melih
    Internal Transcribed Spacer (ITS) is one of the most used barcoding regions for the molecular phylogenetics and barcoding of orchids. Our aim in this study is to test the reliability of ITS on barcoding of closely related Neotinea spp., including Neotinea tridentata, Neotinea ustulata subsp. ustulata and Neotinea ustulata subsp. aestivalis, by comparing it to the accD-psaI intergenic spacer of the plastid DNA. Both ITS and accD-psal regions were amplified by specific primer sets and sequenced. Phylogenetic trees were regenerated by using Maximum Parsimony approach. The results showed that ITS separated some A'. tridentata samples of Turkish, Greek, Hungarian and Croatian samples from the others on the phylogenetic trees due to the incomplete lineage sorting. In contrast to ITS, the accD-psal marker could successfully separate :V. tridentata and N. ustulata samples according to a priori species classification. Our findings refer to a hybridisation story between some N. tridentata and N. ustulata. We propose not to use ITS sequences directly as a barcode and to reconstruct the phylogeny of the Neotinea group. Instead, the inclusion of other nuclear regions such as LFY, ADH etc., or utilisation of whole genome sequencing could give better barcoding results.
  • Küçük Resim
    Öğe
    Neotinea ustulata ve Neotinea tridentata (Orchidaceae) türlerinin filogenetik analizleri üzerine çalışmalar
    (Çanakkale Onsekiz Mart Üniversitesi, Lisansüstü Eğitim Enstitüsü, 2015) Hürkan, Kaan; Taşkın, Kemal Melik
    Çalışmanın amacı: Avrupa ve Anadolu'nun, Akdeniz ve Akdeniz dışı bölgelerinde yayılış gösteren yakın ilişkili Neotinea tridentata (Scop.) R.M.Bateman, Pridgeon & M.W.Chase ve Neotinea ustulata (L.) R.M.Bateman, Pridgeon & M.W.Chase türlerinin nrITS ve accD–psaI DNA dizileri kullanılarak (i) filogenetik yapılarının incelenmesi, (ii) ribotip farklılıklarının test edilmesi, (iii) coğrafi olarak genetik farklılıklara sahip olma durumlarının ortaya çıkarılması ve (iv) iki tür arasında yaşanmış tarihsel bir melezleşme olayının, tartışılmasıdır. N. tridentata ve N. ustulata türlerine ait taze yapraklar Türkiye, Yunanistan, Macaristan, Hırvatistan, Bulgaristan, Çek Cumhuriyeti ve Romanya'dan 2012 – 2014 yılları arasında toplanarak DNA izolasyonu yapılmıştır. Primer çiftleri ile nrITS ve accD–psaI bölgeleri Polimeraz Zincir Reaksiyonu ile çoğaltılmış ve nükleotid dizilişleri ortaya çıkarılmıştır. Genomik ve plastid DNA dizileri Basic Local Search Alignment Tool ile veri bankalarındaki mevcut diziler ile karşılaştırılmıştır. Maximum Likelihood, Maximum Parsimony ve Bayesian Posterior Probability algoritmaları kullanılarak filogenetik ağaçlar çizilmiştir. Ağaçlarda Anadolu ve Avrupa yayılışlı N. tridentata bireyleri farklı kladlara yerleşirken, Anadolu yayılışlı N. tridentata bireyleri ile Avrupa yayılışlı N. ustulata bireyleri aynı klad içerisine yerleşmiştir. Ayrıca bazı Anadolu yayılışlı N. tridentata bireylerinde heterozigoti görülmüştür. Bu sonuçlar Anadolu kaynaklı N. tridentata bireylerinin N. ustulata türü ile bir melezlenme geçmişinin olduğunu göstermektedir. Melezlenme sürecini daha detaylı anlayabilmek ve moleküler tarihleme çalışmaları için bu türlerin tam plastid genomunun dizilenmesini tavsiye etmekteyiz.
  • [ X ]
    Öğe
    Orchis anatolica boıss. ve orchis tridentata Scopolı (Orchidaceae) taksonlarının dna sekans yöntemiyle moleküler filogenetik özelliklerinin belirlenmesi
    (Çanakkale Onsekiz Mart Üniversitesi, 2011) Hürkan, Kaan; Gönüz, Ahmet
    Bu tez çalışmasında Orchis anatolica BOISS. ve Orchis tridentata SCOPOLI (Orchidaceae) taksonlarının, genomik DNA' larının ITS1, 5.8S rDNA ve ITS2 bölgeleri sekanslanarak, moleküler filogenetik ve taksonomik özellikleri ortaya koyulmuştur.Silika ? jel yöntemiyle kurutulan bitki rozet yaprağı (basal yaprak) dokularından genomik DNA izolasyonu yapılmış, ITS1, 5.8S rDNA ve ITS2 bölgesine özel primerlerle PCR işlemi uygulanarak bölge çoğaltılmıştır. Çoğaltılan bölgenin DNA sekanslaması yapılmıştır. Sekanslama işleminden elde edilen veriler, çeşitli biyoinformatik ve filogeni programları ile işlenerek bu taksonların moleküler sınıflandırılmaları ilk kez ortaya koyulmuştur. Çalışmada obje olarak seçilen taksonların, diğer Orchidaceae üyeleriyle olan hizalamaları CLUSTALW2 yazılımı ile, filogenetik ağaç oluşturma işlemi ise MEGA 4.0 (Stable) yazılımı altında Neighbour ? Join (Saitou ve Nei, 1987) metoduyla gerçekleştirilmiştir. Elde edilen distance matrix tablosu ve oluşturulan filogenetik ağaç verileri klasik taksonomi verileri ile karşılaştırılmış, ayrıca O.anatolica ve O.tridentata taksonlarının, seçilen 17 Orchidaceae türü ile ilişkileri incelenmiştir.Bu tez çalışması ile birlikte, O.anatolica ve O.tridentata taksonlarının, nükleer DNA' larının ITS1, 5.8S rDNA ve ITS2 bölgesinden elde edilen sekans verileriyle oluşturulan filogenetik ağaçtaki yerleşimlerinin, klasik taksonomi verilerine benzerlik gösterdiği, fakat O.anatolica taksonu için ITS1, 5.8S rDNA ve ITS2 bölgelerinin moleküler taksonomisi ve filogenisi çalışmalarında kullanılabilirken, O.tridentata taksonunun teşhisi için yeterli bilgiyi içermediği sonucuna varılmıştır.
  • [ X ]
    Öğe
    Structure and expression of dna methyltransferase genes from apomictic and sexual Boechera species
    (Elsevier Sci Ltd, 2017) Taşkın, Kemal Melih; Özbilen, Aslıhan; Sezer, Fatih; Hürkan, Kaan; Güneş, Şebnem
    In this study, we determined the structure of DNA methyltransferase (DNMT) genes in apomict and sexual Boechera species and investigated the expression levels during seed development. Protein and DNA sequences of diploid sexual Boechera stricta DNMT genes obtained from Phytozome 10.3 were used to identify the homologues in apomicts, Boechera holboellii and Boechera divaricaipa. Geneious R8 software was used to map the short -paired reads library of B. holboellii whole genome or B. divaricarpa transcriptome reads to the reference gene sequences. We determined three DNMT genes; for Boechera spp. METHYLTRANSFERASEI (MET I), CHROMOMETHYLASE 3 (CMT3) and DOMAINS REARRANGED METHYLTRANSFERASE 1/2 (DRM2). We examined the structure of these genes with bioinformatic tools and compared with other DNMT genes in plants. We also examined the levels of expression in silique tissues after fertilization by semi -quantitative PCR. The structure of DNMT proteins in apomict and sexual Boechera species share common features. However, the expression levels of DNMTgenes were different in apomict and sexual Boechera species. We found that DRM2 was upregulated in apomicticBoechera species after fertilization, Phylogenetic trees showed that three genes are conserved among green algae, monocotyledons and dicotyledons. Our results indicated a deregulation of DNA methylation machinery during seed development in apomicts. (C) 2016 Elsevier Ltd. All rights reserved.