Molecular Phylogeny of the Neotropical Genus Christensonella (Orchidaceae, Maxillariinae): Species Delimitation and Insights into Chromosome Evolution

Koehler, Samantha; Cabral, Juliano Sarmento; Whitten, W. Mark; Williams, Norris H.; Singer, Rodrigo B.; Neubig, Kurt M.; Guerra, Marcelo; Souza, Anete Pereira de; Amaral, Maria do Carmo Estanislau do

doi:10.1093/aob/mcn128

Cited by 29 publications

(60 citation statements)

References 39 publications

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“…The variability of chromosome number and genome organization (heterochromatin and rDNA localization) can provide reliable information to analyze the taxonomic relationship Guerra 2000, 2010;Koehler et al 2008). The elevation of chromosome number has been discovered in many orchid genera, generated from the basic chromosome number by hybridization, polyploidization or dysploid formation (Cox et al 1998;Félix and Guerra 2005).…”

Section: Two Cytotypes or Different Species?mentioning

confidence: 99%

Two reported cytotypes of the emergent orchid model species Erycina pusilla are two different species

et al. 2017

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Each species is characterized by a specific set of chromosomes, which is described as the chromosome portrait or karyotype. In general, such a karyotype is the same for all individuals in the population. An exception to that rule has recently been found in the orchid Erycina pusilla, which has been reported to have two cytotypes with chromosome numbers of 2n = 10 and 2n = 12. Here, we examined the karyotypes of the two cytotypes and found differences in arm ratios and heterochromatin patterns as well as in the presence of satellite chromosomes and in the number and location of rDNA and telomeric repeat sites. These differences are extensive and would have required multiple chromosome rearrangements to generate the differences between the two karyotypes. We also found that F1 hybrids between the parents with the two different chromosome numbers resulted in sterile offspring, in accordance with our previous findings. The combination of hybrid sterility and extensively rearranged chromosomes supports the hypothesis that these two reported cytotypes are, in fact, two different species.

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Section: Two Cytotypes or Different Species?mentioning

confidence: 99%

Two reported cytotypes of the emergent orchid model species Erycina pusilla are two different species

et al. 2017

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“…Diferentemente, as espécies de Alatiglossum stricto sensu e Kleberiella apresentam as sépalas laterais parcialmente conatas e calos em forma de crista (Castro Neto & Catharino 2006). terização de cariótipos entre espécies com o mesmo número cromossômico e revelaram detalhes sobre a evolução e a diversidade de espécies em Orchidaceae e outras famílias de plantas (Dematteis 1997;Corrêa 2003;Cozzollino et al 2004;Koehler et al 2008).…”

Section: Variação Do Número Cromossômicounclassified

“…Variações semelhantes foram observadas em outros gêneros de Oncidiinae como a perda cromossômica em Macradenia que apresenta espécies com 2n = 48 e 56, o acréscimo de pares cromossômicos na mesma espécie, como em Miltonia spectabilis com 2n = 56 e 60, a disploidia em Lockartia com 2n = 14 e 56, e a poliploidia em Odontoglossum, com 2n = 56 e 112 (Félix & Guerra 2000). Estas variações são observadas em muitos outros gêneros da subtribo, assim como em gêneros de outras subtribos de Cymbidieae como Christensonella (Maxillariinae) que apresenta espécies com 2n = 36, 38 e 76 (Koehler et al 2008).…”

Section: Evolução Cromossômica Numéricaunclassified

“…Em muitos casos, a simples determinação do número cromossômico fornece informações importantes para a compreensão da fi logenia, evolução (Stebbins 1971) e ca-racterização de gêneros e espécies de difícil delimitação em Orchidaceae, como em outras famílias de angiospermas, desde que associada a outras abordagens como fi logenia, morfologia e distribuição geográfi ca (Stace 1989;Corrêa 2003, Cozzollino et al 2004Francesca & Aquaro 2008;Koehler et al 2008;Chase et al 2009;Soltis & Soltis 2009). Assim, o objetivo deste trabalho foi verifi car a variação do número cromossômico em espécies de Kleberiella e de algumas espécies de gêneros relacionados fi logeneticamente dentro do clado Barbata (Alatiglossum, Neoruschia e Carenidium), verifi cando se este número pode ser utilizado na taxonomia do grupo, corroborando ou não alguma das circunscrições genéricas propostas para o clado, bem como fornecer dados inéditos para compreensão da evolução cromossômica numérica em Oncidiinae Os meristemas radiculares foram pré-tratados com 8-Hidroxiquinoleína 0,002 M e armazenados por 24 horas em geladeira a 5ºC e depois fi xados em Carnoy (ácido acé-tico glacial : etanol, 1:3) por mais 24 horas.…”

Section: Introductionunclassified

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Números cromossômicos em Kleberiella V.P. Castro & Cath. (Orchidaceae, Oncidiinae) e gêneros afins

Penha¹,

Corrêa²,

Catharino³

2011

Acta Bot. Bras.

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Números cromossômicos em Kleberiella V.P. Castro & Cath. (Orchidaceae, Oncidiinae) e gêneros afi ns RESUMO (Números cromossômicos em Kleberiella V.P. Castro & Cath. (Orchidaceae, Oncidiinae) e gêneros afi ns). Este trabalho teve como objetivo principal realizar a análise citotaxonômica de espécies fi logeneticamente relacionadas dentro dos gêneros Kleberiella, Alatiglossum e Neoruschia com base na determinação dos seus números cromossômicos a partir dos seus meristemas radiculares. Foram obtidos os números cromossômicos de todas as espécies de Kleberiella (seis espécies), Neoruschia (monoespecífi co) e de quatro das nove espécies conhecidas para Alatiglossum stricto sensu. Exceto para K. longipes, A. barbatum e A. micropogon, os quais corroboram com resultados anteriores, todos os outros números cromossômicos são inéditos. A contagem cromossômica se mostrou como um caráter taxonômico útil na delimitação de Alatiglossum fuscopetalum (2n = 52) e do gênero Neoruschia (2n = 48) das outras espécies analisadas. Entretanto não se mostrou efi ciente para delimitação entre as espécies de Kleberiella (todas com 2n = 56) e para separar este gênero de Alatiglossum no qual a maioria das espécies analisadas apresentou 2n = 56. O numero básico sugerido para Alatiglossum e Kleberiella é x = 28 e para Neoruschia x = 24. Th is work aimed to provide cytotaxonomical analysis of species phylogenetically related within the genera Kleberiella, Alatiglossum and Neoruschia based on the determination of chromosome numbers from root meristems. We obtained the chromosome numbers of all species of Kleberiella (six species), Neoruschia (monospecifi c) and four of the nine known species of Alatiglossum stricto sensu. Except for K. longipes, A. barbatum and A. micropogon, which corroborate previous results, all other chromosome numbers are unpublished. Chromosome counting proved useful as a taxonomic character in the delimitation of Alatiglossum fuscopetalum (2n = 52) and the genus Neoruschia (2n = 48) from the other species analyzed. However it was not effi cient for delimitation between Kleberiella species (all with 2n = 56) and to separate this genus from Alatiglossum in which most of the species studied had 2n = 56. Th e provable basic number for Alatiglossum and Kleberiella is x = 28 and for Neoruschia x = 24. Palavras-chave:

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“…Traditionally, cytogenetic data have been superimposed onto phylogenetic trees to identify chromosome rearrangements throughout the evolution of the karyotype [24–25]. However, statistical approaches, as ancestral state reconstruction based on maximum likelihood, have recently been applied to infer karyotype evolution in a phylogenetic framework [11, 16, 26–28].…”

Section: Introductionmentioning

confidence: 99%

Detecting Mechanisms of Karyotype Evolution in Heterotaxis (Orchidaceae)

et al. 2016

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The karyotype is shaped by different chromosome rearrangements during species evolution. However, determining which rearrangements are responsible for karyotype changes is a challenging task and the combination of a robust phylogeny with refined karyotype characterization, GS measurements and bioinformatic modelling is necessary. Here, this approach was applied in Heterotaxis to determine what chromosome rearrangements were responsible for the dysploidy variation. We used two datasets (nrDNA and cpDNA, both under MP and BI) to infer the phylogenetic relationships among Heterotaxis species and the closely related genera Nitidobulbon and Ornithidium. Such phylogenies were used as framework to infer how karyotype evolution occurred using statistical methods. The nrDNA recovered Ornithidium, Nitidobulbon and Heterotaxis as monophyletic under both MP and BI; while cpDNA could not completely separate the three genera under both methods. Based on the GS, we recovered two groups within Heterotaxis: (1) "small GS", corresponding to the Sessilis grade, composed of plants with smaller genomes and smaller morphological structure, and (2) "large GS", corresponding to the Discolor clade, composed of plants with large genomes and robust morphological structures. The robust karyotype modeling, using both nrDNA phylogenies, allowed us to infer that the ancestral Heterotaxis karyotype presented 2n = 40, probably with a proximal 45S rDNA on a metacentric chromosome pair. The chromosome number variation was caused by ascending dysploidy (chromosome fission involving the proximal 45S rDNA site resulting in two acrocentric chromosome pairs holding a terminal 45S rDNA), with subsequent descending dysploidy (fusion) in two species, H. maleolens and H. sessilis. However, besides dysploidy, our analysis detected another important chromosome rearrangement in the Orchidaceae: chromosome inversion, that promoted 5S rDNA site duplication and relocation.

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Molecular Phylogeny of the Neotropical Genus Christensonella (Orchidaceae, Maxillariinae): Species Delimitation and Insights into Chromosome Evolution

Cited by 29 publications

References 39 publications

Two reported cytotypes of the emergent orchid model species Erycina pusilla are two different species

Two reported cytotypes of the emergent orchid model species Erycina pusilla are two different species

Números cromossômicos em Kleberiella V.P. Castro & Cath. (Orchidaceae, Oncidiinae) e gêneros afins

Detecting Mechanisms of Karyotype Evolution in Heterotaxis (Orchidaceae)

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