Topic
Nothoscordum
About: Nothoscordum is a research topic. Over the lifetime, 40 publications have been published within this topic receiving 687 citations.
Papers
TL;DR: The internal transcribed spacer region of nuclear ribosomal DNA was sequenced from 195 representative species of Allium, two species of Nothoscordum, and one species each of Ipheion, Dichelostemma, and Tulbaghia to form a new classification of genus Allium consisting of 15 monophyletic subgenera.
Abstract: The internal transcribed spacer region (ITS) of nuclear ribosomal DNA was sequenced from 195 representative species of Allium, two species of Nothoscordum, and one species each of Ipheion, Dichelostemma, and Tulbaghia. Within the Allium species the lengths of the ITS regions were in a range from 612 to 661 base pairs and pairwise genetic distances reached up to 46%. The ITS data supported the inclusion of Nectaroscordum, Caloscordum, and Milula into Allium. Subgenera Rhizirideum and Allium, as well as sects. Reticulatobulbosa and Oreiprason were non-monophyletic taxa. Based on the phylogenetic relations, a new classification of genus Allium consisting of 15 monophyletic subgenera is presented. Sections Microscordum, Anguinum, Porphyroprason, Vvedenskya, Butomissa, Cyathophora, and Reticulatobulbosa are raised to subgeneric rank. Sections Austromontana N. Friesen, Eduardia N. Friesen, Mediasia F. 0. Khassanov, S. C. Yengalycheva et N. Friesen, Nigrimontana N. Friesen, Falcatifolia N. Friesen, and Condensatum N. Friesen are newly described. Series Daghestanica, Pallasia, and Scabriscapa, as well as subsects. Eremoprasum, Longivaginata, and Sikkimensia are raised to sectional rank. A taxonomic conspectus of Allium at sectional level is given.
422 citations
TL;DR: Using fluorescent in situ hybridisation, slot blotting and the asymmetric polymerase chain reaction, it is demonstrated an absence of Arabidopsis-type telomeres in the genus Aloe (family Asphodelaceae), which is suggested to be characteristic of this related group of plants.
Abstract: The physical ends of chromosomes are protected and stabilised by telomeres. The sequence of telomeric DNA normally consists of a simple repeating unit that is conserved in many organisms. Most plants examined have been shown to possess Arabidopsis-type telomeres consisting of many repeat copies of the sequence 5'-TTTAGGG-3'. Using fluorescent in situ hybridisation, slot blotting and the asymmetric polymerase chain reaction we demonstrate an absence of Arabidopsis-type telomeres in the genus Aloe (family Asphodelaceae). The only other plant genera so far reported without such telomeres are Allium, Nothoscordum, and Tulbaghia (family Alliaceae). As these genera and Aloe are petaloid monocots in the Asparagales, it is suggested that an absence of Arabidopsis-type telomeres may be characteristic of this related group of plants.
60 citations
TL;DR: Tetraploid apomicts seem to constitute an assemblage of polyploid hybrids originating from multiple independent hybridization events between them, part of which are morphologically recognizable as N. gracile.
41 citations
TL;DR: Tetraploid populations of I. uniflorum, probably autopolyploids of recent origin, with karyotype similar to the diploids, are described herein for the first time.
Abstract: Ipheion Rafinesque is a small genus formed by I. uniflorum (2n = 12, 2SM + 10A), I. tweedieanum (2n = 14A), and I. recurvifolium (2n = 20, 4SM + 16A). Three species of Nothoscordum, N. felipponei, N. hirtellum, and N. vittatum (2n = 10, 6M + 4A), were also later transferred to Ipheion based on the common presence of unifloral inflorescence. Karyotype analysis of the five former species was performed in this work, aiming to evaluate the circumscription of the genus. This analysis was based on chromosome size and morphology, asymmetry index, staining with chromomycin A3 (CMA) and 4′,6-diamidino-2-phenylindole (DAPI), and in situ hybridization with 5S and 45S rDNA probes. Tetraploid populations of I. uniflorum, probably autopolyploids of recent origin, with karyotype similar to the diploids, are described herein for the first time. Grouping analyses of the several sets of characters analyzed show the former three Ipheion species clearly separated from the Nothoscordum ones, which were more proximally related to other Nothoscordum species. Chromosome size, asymmetry indices, and number and position of 5S and 45S rDNA sites were the most important karyotype characters to define the genus Ipheion. These data indicate that the unifloral species of Nothoscordum belong to Nothoscordum and not to Ipheion, and the “unifloral inflorescence” should be a homoplasy common to both genera.
37 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2019 | 2 |
| 2018 | 1 |
| 2016 | 2 |
| 2015 | 1 |
| 2014 | 2 |