Karyological circumscription of Ipheion Rafinesque (Gilliesioideae, Alliaceae)

Souza, Gustavo; Crosa, Orfeo; Guerra, Marcelo

doi:10.1007/s00606-010-0304-3

Cited by 29 publications

(67 citation statements)

References 21 publications

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“…This suggests that the karyotype differentiation of Zoellnerallium occurred through polyploidization events and centric fissions (Crosa 1975(Crosa , 2004. The most evident karyotype differences between Leucocoryne and Nothoscordum refer to the short arm of the acrocentric chromosome of Nothoscordum, which is generally very small (Crosa 1988) and harbors only 45S rDNA sites (Guerra and Felix 2000;Souza et al 2009Souza et al , 2010Souza et al , 2012. The short arms of the acrocentric chromosomes in Leucocoryne are generally larger, being referred to as subtelocentric (st) or telocentric (t) (Crosa 1988;Jara-Arancio et al 2012).…”

Section: Discussionmentioning

confidence: 97%

“…These species were chosen because they have been previously analyzed with the same citomolecular techniques, which allowed us to make a comparative cytogenetics analysis (Guerra and Felix 2000;Souza et al 2009Souza et al , 2010Souza et al , 2012. The ITS sequences of all species were retrieved from a previous study (see Genbank accessions number in Online Resource 1), except for Nothoscordum pulchellum Kunth.…”

Section: Phylogenetic Analysismentioning

confidence: 99%

“…Additionally, species of the same genus can differ from each other in terms of the number and position of their heterochromatic bands or rDNA sites (Souza et al 2010(Souza et al , 2012. Therefore, a more detailed comparative cytogenetic approach could contribute to elucidate the relationships between the species of Leucocoryne with three and six stamens.…”

Section: Introductionmentioning

confidence: 98%

“…In addition to chromosome number and morphology, analyses of the distribution of heterochromatic bands [identified by applying the fluorochromes chromomycin A3 (CMA) and 4 0 -6-diamidino-2-phenylindole (DAPI)] and fluorescent in situ hybridization (FISH) with 5S and 45S rDNA have been shown to represent important approaches to distinguish groups of species of other genera in the tribe Ipheieae (Souza et al 2010(Souza et al , 2012. These data may be better interpreted with the incorporation of molecular phylogenies and analyses of character reconstructions, which would allow us to more clearly interpret the karyotypic evolution of the group (Vaio et al 2013).…”

Section: Introductionmentioning

confidence: 99%

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Karyological, morphological, and phylogenetic diversification in Leucocoryne Lindl (Allioideae, Amaryllidaceae)

2015

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The genus Leucocoryne (Amaryllidaceae) comprises approximately 15 species and is the only genus of the tribe Ipheieae endemic to the western region of Chile in sclerophyll and arid winter-rainfall biomes in the Andes. To better understand the karyotype diversification of this genus, nine species of Leucocoryne were analyzed in terms of their chromosome number and morphology, CMA and DAPI heterochromatic bands, distribution of rDNA sites, and their molecular phylogenetic relationships. Based on phylogenetic analyses Leucocoryne was divided in four clades: I (L. alliacea and L. conferta); II (L. dimorphopetala and L. narcisoides); III (L. coquimbensis, L. macropetala, L. appendiculata, L. talinensis, L. angustipetala, L. purpurea, and L. violacescens); and IV (L. vittata, L. ixioides, L. foetida, and L. pauciflora). The species were diploids with 2n = 10 (6M ? 4A) or tetraploids with 2n = 18 (14M ? 4A)/2n = 19 (13M ? 6A). 45S rDNA sites were co-localized with CMA ? /DAPIbands on the short arms of acrocentric chromosomes in all species. 5S rDNA sites were observed on one, two, or four pairs of metacentric chromosomes per species. Estimations of the ancestral karyotype suggest that 2n = 10 (6M ? 2A) with one 5S rDNA site per monoploid complement was the plesiomorphic condition of the genus Leucocoryne. Increases in number of 5S rDNA sites in the same species associated with biome shifts from sclerophyll to arid winter-rainfall region occurred independently in clade II and clade III. The two species of clade II retained the six fertile stamens (plesiomorphic condition) in contrast to the other Leucocoryne species that reduced to only three functional stamens. Based on these findings, we discuss the role of environmental change on the diversification of this group.

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Section: Discussionmentioning

confidence: 97%

Section: Phylogenetic Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Karyological, morphological, and phylogenetic diversification in Leucocoryne Lindl (Allioideae, Amaryllidaceae)

2015

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“…The localization of the 5S rDNA unit independently from other rDNA sequences may be related to the fact that the 5S unit is transcribed by RNA polymerase III, while the polycistronic 45S rDNA uses RNA polymerase I [Garcia and Kovařík, 2013]. These sites can also occur on the same chromosome in separated positions (non-adjacent), as in species of Ipheion and Nothoscordum [Souza et al, 2010], or adjacent to each other, sometimes distinguishable only in prophase and interphase [Brasileiro-Vidal et al, 2007; Barros e Silva et al, 2013].…”

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confidence: 99%

Non-Random Distribution of 5S rDNA Sites and Its Association with 45S rDNA in Plant Chromosomes

Roa¹,

Guerra²

2015

Cytogenet Genome Res

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5S and 45S rDNA sites are the best mapped chromosome regions in eukaryotic chromosomes. In this work, a database was built gathering information about the position and number of 5S rDNA sites in 784 plant species, aiming to identify patterns of distribution along the chromosomes and its correlation with the position of 45S rDNA sites. Data revealed that in most karyotypes (54.5%, including polyploids) two 5S rDNA sites (a single pair) are present, with 58.7% of all sites occurring in the short arm, mainly in the proximal region. In karyotypes of angiosperms with only 1 pair of sites (single sites) they are mostly found in the proximal region (52.0%), whereas in karyotypes with multiple sites the location varies according to the average chromosome size. Karyotypes with multiple sites and small chromosomes (<3 µm) often display proximal sites, while medium-sized (between 3 and 6 µm) and large chromosomes (>6 µm) more commonly show terminal or interstitial sites. In species with holokinetic chromosomes, the modal value of sites per karyotype was also 2, but they were found mainly in a terminal position. Adjacent 5S and 45S rDNA sites were often found in the short arm, reflecting the preferential distribution of both sites in this arm. The high frequency of genera with at least 1 species with adjacent 5S and 45S sites reveals that this association appeared several times during angiosperm evolution, but it has been maintained only rarely as the dominant array in plant genera.

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One species with a disjunct distribution or two with convergent evolution? Taxonomy of two South American garlics

Sassone

Arroyo

Arroyo-Leuenberger

et al. 2021

TAXON

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The establishment of species boundaries has been a difficult task for biologists since the beginning of classifications. Within South American Allioideae (= Alliaceae), the delimitation of genera and species has long been a major challenge. Consequently, species‐level nomenclature in these groups has been difficult to elucidate. Ipheion and Tristagma are two closely related South American genera for which the delimitation and circumscription of several species continue to be unclear. Tristagma sessile, a species inhabiting the Andes and the Coast Range in Chile, and Ipheion recurvifolium, a species native to Uruguay only found close to sea level, have been considered as one species with an intracontinental disjunct distribution. The divergent habitats and distributions of these taxa have stirred the question of whether they are a single species. The present study aims to elucidate the evolutionary relationships and status of the Chilean and Pampean taxa. We also analysed the name Tristagma leichtlinii, which has long been a source of confusion. Based on their phylogenetic relationships, geographical distributions, flowering periods, and DNA content, we conclude that the two taxa are different species and assignable to separate genera. We propose that the morphological similarity of Ipheion recurvifolium and Tristagma sessile, amply corroborated in this study, might be the sum of shared synapomorphies (between Ipheion and Tristagma) and convergent features. We update the biogeographic history of the two genera and propose that similar pollinators might underpin the convergence in floral traits. We outline the differences among genera and species, present a taxonomic review with a new lectotype and consider the conservation status of the studied species.

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Karyological circumscription of Ipheion Rafinesque (Gilliesioideae, Alliaceae)

Cited by 29 publications

References 21 publications

Karyological, morphological, and phylogenetic diversification in Leucocoryne Lindl (Allioideae, Amaryllidaceae)

Karyological, morphological, and phylogenetic diversification in Leucocoryne Lindl (Allioideae, Amaryllidaceae)

Non-Random Distribution of 5S rDNA Sites and Its Association with 45S rDNA in Plant Chromosomes

One species with a disjunct distribution or two with convergent evolution? Taxonomy of two South American garlics

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