Search results for "Chromosome number"
showing 10 items of 26 documents
Loncomelos koprulense (Asparagaceae), a new species from southern Turkey
2021
A new species, Loncomelos koprulense (Asparagaceae), is described and illustrated from southern Turkey. It is a very rare endemic species growing on small semi-rocky escarpments within the Köprülü Kanyon in the province of Antalya. Morphologically for its hairy leaves, L. koprulense shows some relationships with L. malatyanum and L. tardum, species localized in Anatolia too. The chromosome number of the new species is 2n = 2x = 22. Geographical distribution map for L. koprulense, L. malatyanum and L. tardum is provided.
Karyotype variability and inter-population genomic differences in freshwater ostracods (Crustacea) showing geographical parthenogenesis
2018
Transitions from sexual to asexual reproduction are often associated with polyploidy and increased chromosomal plasticity in asexuals. We investigated chromosomes in the freshwater ostracod species Eucypris virens (Jurine, 1820), where sexual, asexual and mixed populations can be found. Our initial karyotyping of multiple populations from Europe and North Africa, both sexual and asexual, revealed a striking variability in chromosome numbers. This would suggest that chromosomal changes are likely to be accelerated in asexuals because the constraints of meiosis are removed. Hence, we employed comparative genomic hybridization (CGH) within and among sexual and asexual populations to get insigh…
The tropical African genus Morgenia (Orthoptera, Tettigoniidae, Phaneropterinae) with emphasis on the spur at the mid tibia
2018
The authors revised the genus Morgenia Karsch, 1890 which now consists of eight species, of which three are here newly described (Morgeniaplurimaculata Massa & Moulin, sp. n., M.angustipinnata Massa, sp. n., and M.lehmannorum Heller & Massa, sp. n.). Six of the eight species occur in the Tri National Sangha (TNS) comprising Dzanga-Sangha Special Reserve and Dzanga Ndoki National Park (Central African Republic), whose high biodiversity has been recently highlighted. In particular the genus is characterised by the presence of a more or less long spur at the inner mid tibia, different in each species; in M.modulata, it moved lower down into a new position at about ¼ of tibia, w…
New conservation viewpoints when plants are viewed at one level higher. Integration of phylogeographic structure, niche modeling and genetic diversit…
2019
Protection and management of closely related endangered species and subspecies at a very narrow regional scale is the origin of multiple dysfunctional conservation decisions. These include artificially increased IUCN risk assessment categories and derived consequences: poor effectiveness in allocating public and private funds or repeat of unnecessary actions/facilities. Data provided by the revisited study of a group of W Mediterranean larkspurs (Delphinium ser. Fissa), including new data on demography, niche modeling, genetic diversity and phylogeography, contributed to a new and wider analysis of causes of threat. Although current IUCN Red List regulations did not allow for assessments at…
Chromosomes of the Parasitic Isopod Anilocra Physodes
1996
AbstractCounts of mitotic chromosomes have allowed to determine 2n = 12 as the modal diploid number of Anilocra physodes. Application of the C-banding technique reveals that two hetero-chromatic blocks bordering the centromeric region occur in each chromosome. This supports the notion that the actual low chromosome number of A. physodes may have been derived through a process of Robertsonian fusion.
Morphological, karyological and taxonomic remarks on Ferulago nodosa (L.) Boiss. (Apiaceae)
2012
Abstract Western (Sicilian) and eastern (Balcan-aegean) populations of the Balcan-tyrrhenian Ferulago nodosa are reported to be different in some morphological characters, and were considered different species by some authors in XIX century. In this work, fruit and pollen morphologies have been compared in Sicilian and Cretan plants; also, the chromosome number of Sicilian plants has been ascertained. Preliminary results highlight a general homogeneity between the two populations, nevertheless showing significant differences in some parameters (fruit form, pollen size). For this reason, and considering the geographic disjunction of the Sicilian plants, the two populations are proposed to be…
Variability of isozyme pattern, chromosome number, and latex colour and components in the closely related Papaver duhium L. and P. lecoqii Lamotte in…
1995
Summary The variability of nine different isozyme systems, chromosome number, colour of fresh and dried latex and presence or absence of meconic acid was investigated in altogether 45 populations of Papaver dubium and P. lecoqii mainly from C Europe. It was found that P. dubium is hexaploid with 2n = 42 chromosomes, has brown dried latex, and contains meconic acid. P. lecoqii is tetraploid with 2n = 28 chromosomes, has red dried latex, and lacks meconic acid. The two taxa can also be distinguished by differences in three of the nine isozymes analysed, and are almost completely monomorphic for their respective isozyme pattern. It is concluded that the two taxa, which cannot be reliably disti…
Is <i>Limonium cavanillesii</i> Erben (Plumbaginaceae) really an extant species?
1999
A new triploid apomictic species (Limonium perplexum) is described from a single coastal locality of E Spain. The new species has been previously confused with L cavanillesii Erben, which is only known from few herbarium specimens and it is believed to be extinct. Overall morphology, chromosome number, and the pollen/stigma combination suggest that L perplexum belongs to the L. duriusculum complex. Based on morphological grounds it is suggested that L. cavanillesii Erben could have been originated through a crossing between L perplexum and L dufourii .
<i>Limonium marisolii</i> L. Llorens (Plumbaginaceae) revisited
1998
A new triploid agamic species, L. leonardi-llorensii , is described from coastal populations of South-West Mallorca. The new species is closely related, on morphological grounds, to the endemic L. marisolii L. Llorens, from which it could be distinguished by several morphological characters (leaves without papillae, longer calyx, more flowers per spikelet) and by a different chromosome number ( 2n = 26, L. leonardi-llorensii ; 2n = 27, L. marisolii ). The relationships between both species are discussed, and it is suggested that both taxa might share some common evolutionary history despite their divergent chromosome number. The origin of L. marisolii from L. leonardi-llorensii through chro…
The taxonomic status of <i>Scilla beirana</i> Samp. (<i>Hyacinthaceae</i>)
1998
ALMEIDA DA SILVA, R.M., F.B. CALDAS & J.A. ROSSELLO (1998). The taxonomic status of Scilla beirana Samp. (Hyacinthaceae). Anales Jard. Bot. Madrid 56(2): 253-260. Populations of Scilla beirana Samp. were sampled in NW Portugal and compared with its relatives S. ramburei Boiss, and S. peruviana L. Leaf and scape anatomy, morphology, chromosome number and idiogram were identical in S. beirana and S. ramburei, but differed from S. peruviana. Diagnostic characters previously used to discriminate S. beirana (width of leaves and flower number) showed continuous, but not clinal, variation, and failed to provide a clear-cut basis for identification and no other morphological attributes were found t…