Micro- and macromorphological achene features of 20 knapweeds taxa from Turkey were searched using light and scanning electron microscopy. The achene surface was examined in detail for each taxon and a dendogram was established by numerical analyses derived from the observed micromorphological features. Cyanus pinardii was distinguished by epappose while Cyanus depressus was distinguished by longer pappus than achene. The results indicated that the examined taxa had very high variations in their achene surface. According to the results, pericarp texture and color, hilum position and pappus hairs could be used for taxonomical diagnosis of the Cyanus taxa. The hairiness of the surface and elaiosome in the basal of pericarp were characteristic in all Cyanus taxa.
lanceolate or linear-lanceolate, involucre ovoid or ovoid-subglobose, radiant; appendages decurrent, ciliate, not ending in mucro or mucronulate, laceration absent, with blackish or brownish border, usually ovateoblong or ovate-triangular; florets usually violet or blue, rarely whitish, yellowish, pink, or red; marginal florets with 5-6 lobes, sterile, without staminodes, central flowers hermaphrodite; achenes generally ovoid-oblong, insertion areole hairy, mostly with pappus, pappus scabrose or barbellate-scabrose (Wagenitz, 1975). During our field study, some specimens belonging to subgenus Cyanus were collected and then identified according to Flora of Turkey (Wagenitz, 1975). Some clear morphological differences between the collected specimens and C. bourgaei enabled us to describe them as a new species. 2. Materials and methods The new species material was compared to the herbarium collections of Centaurea in ANK, HUB, GAZI, ISTF, ISTE, and KNYA (acronyms follow Thiers, 2018). The morphology of the specimens was examined under a binocular microscope, and the specimens were compared with closely related species: C. bourgaei, C. pichleri, and C. reuteriana. Moreover, the type specimens of the related species were viewed as digital photographs. The achenes of 2 species were dehydrated in an alcohol series (70%, 80%, 96%, and 100%) for cleaning and coated with gold for viewing under a ZEISS EVO LS-10 model scanning electron microscope (SEM) on high-vacuum mode to observe their surfaces at magnifications of 30×, 1000×, and 2000×. The terminology of the achene characteristics was according to Stearn (1995) and Koul et al. (2000). Mature achenes were selected and germinated for chromosomal analysis. Counting of the chromosomes was conducted during the somatic metaphase using the squash technique. Primer root meristems were used to obtain the metaphase plates. The samples were pretreated with 0.002 M 8-hydroxyquinoline for 8 h at 4 °C and then fixed with Carnoy's solution for 24 h at a low temperature. Prior to dyeing, the material was hydrolyzed with 5N HCl for 30 min at room temperature and stained with 1% acetoneorcein. The preparates were made permanent according to the method of Bowen (1956). At least 5 metaphases were examined and the best image was photographed at Research Article This work is licensed under a Creative Commons Attribution 4.0 International License.
In this study, the karyomorphology of five endemic Arabis taxa (A. alanyensis, A. androsacea, A. aubrietioides, A. davisii, and A. deflexa) was examined. The chromosome number of these species was determined for the first time. As a result of the karyomorphological studies, the chromosome number was determined to be x =8 for all species. Arabis androsacea and A. aubrietioides are tetraploid whereas other species are diploid. Considering the asymmetry indices, we can conclude that all taxa have symmetrical karyotypes. The most common karyotype formulas are 2n = 4x = 32m and 2n = 2x = 14m + 2sm, respectively. Arabis davisii (on the second chromosome pair) and A. deflexa (on the third chromosome pair) are distinguished from others by showing a secondary constriction.
The fruit and seed morphologies of five taxa (Al. desertorum Sapf., Al. linifolium Stephan ex. Willd. var. teheranicum Bornm., Al. minus (L.) Rothm. var. minus, Al. strigosum Banks & Sol. subsp. cedrorum (Schott & Kotschy) and Al. strigosum Banks & Sol. subsp. strigosum) belonging to Alyssum L. were investigated with scanning electron microscopy (SEM) in order to determine the significance of fruit and seed features as taxonomic characters. This study presents macro-and micromorphological characters, including seed shape, winged, measures, epidermal cell pattern and fruit shape, colour, measures, trichome morphology. Three epidermal cell patterns were observed; micro-reticulate, normal-reticulate, rugose-foveate and the same number trichome morphologies were distinguished; glabrous, monomorphic (stellate), dimorphic (bifurcate and stellate). The results showed that the morphological characteristics of fruit and seed could be used as criteria to distinguish taxa.
Introduction Cytotaxonomy is a branch of cytogenetics in which karyological features are systematically evaluated for evolutionary purposes (Siljak-Yakovlev and Peruzzi, 2012). Chromosomes, especially plant chromosomes, are useful materials in nearly any type of cytogenetic research (Guerra, 2012). Because the genetic information of an organism is transmitted through its chromosomes, any changes in numbers (e.g., polyploid or diploid) and structures (e.g., inversion, deletion, or translocation) contribute significantly to plant evolution and speciation; however, to interpret the evolutionary history of a group, the number of chromosomes alone is not enough (Weiss-Schneeweiss and Schneeweiss, 2003) and karyomorphology might supply additional information. In some cases, ecological and morphological data might not be sufficient for analyzing the line of descent among the species. In these situations, cytotaxonomic relationships along with molecular data might be more influential in the analyses (Venora et al., 2008). The karyotype reveals phenotypic appearance in terms of number, size, arm ratio, centromere position, and other basic characteristics of chromosomes (Levin, 2002). Centaurea, which belongs to the tribe Cardueae, is a large genus with approximately 250 species (Susanna and Garcia-Jacas, 2007) and the highest rate of endemism, with 112 endemics among the total 181 species in Turkey (Uysal, 2012). Cyanus, a subgenus, is represented by approximately 25 species worldwide (Hellwig, 2004). According to recent definitions of Centaurea (Susanna and Garcia-Jacas, 2007), the following 3 subgenera are included: Acrocentron, Centaurea, and Cyanus. Sister relationships of Cyanus and Centaurea are firmly established, but the connections between these subgenera and Acrocentron are unclear (Susanna and Garcia-Jacas, 2009). Based on current molecular studies, for the aims of our research, Cyanus is considered a subgenus. Taxonomically, Cyanus was first described as a genus by Miller (1754). The group was subsequently reassigned as a section of Centaurea by de Candolle (1838) and this was widely accepted by taxonomists (Bentham, 1873; Boissier, 1875; Wagenitz, 1975). It is now generally accepted that Cyanus is a subgenus (Hilpold et al., 2014) or, rarely, a group (Wagenitz and Hellwig, 1996; Garcia-Jacas et al., 2001) within Centaurea; however, some authors still assert that it is a genus (Greuter, 2003; Bancheva and Greilhuber, 2006). The Cyanus group is distributed across central and southern Europe, North Africa, Anatolia, and the Caucasus, and some species have spread to Iran and Afghanistan (Boršić et al., 2011). The floret colors are blue or purplish blue in this group, with a few exceptions of taxa that are cream or Research Article This work is licensed under a Creative Commons Attribution 4.0 International License.
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