Chromosome studies in Orchidaceae: karyotype divergence in Neotropical genera in subtribe Maxillariinae

Moraes, Ana Paula; Leitch, Ilia J.; Leitch, Andrew R.

doi:10.1111/j.1095-8339.2012.01266.x

Cited by 22 publications

(28 citation statements)

References 33 publications

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“…However, the occurrence of GC-rich heterochromatin on the terminal regions of all chromosomes in H .bicornis has not been reported for any other orchid species. The evolution of CMA/DAPI band patterns in subtribe Maxillariinae is highly variable within and between different monophyletic lineages and has been important for the cytotaxonomic characterization of several species (Moraes et al 2012). If this is also true for Habenaria, CMA/DAPI band patterns may provide an additional tool for characterization of lineages and species and for testing phylogenetic hypothesis in the genus.…”

Section: Resultsmentioning

confidence: 99%

From Cuba to most of the neotropic: habenaria bicornis (orchidaceae) is widespread from Mexico to southeastern Brazil

Batista¹,

Proite²,

Carvalho³

et al. 2014

Lankesteriana

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Habenaria bicornis fue descrita por primera vez en 1835, para Cuba, y era conocida apenas para este país y unos pocos registros de Panamá, de 1920. En el presente estudio, demostramos que H. bicornis y H. goyazensis, esta última conocida para Brasil y Guiana, son específicas y la especie se distribuye desde México hasta el sudeste de Brasil. El modelado de nicho y la recolección de datos indican que esta especie posee una preferencia por sabanas húmedas de tierras bajas y es predicho que su distribución incluye gran parte del Neotrópico con hábitats favorables. Los análisis filogenéticos moleculares con secuencias del ADN nuclear (ITS) y plastidial (matK) ubicaron H. bicornis en una posición aislada próximo a la base del clado Neotropical, aunque con bajo soporte. En términos de su morfología, sus relaciones no están aclaradas, ya que no hay similitudes evidentes entre H. bicornis y los subclados básales o cualquier otro subclado Neotropical. Los análisis citogenéticos indican un número cromosómico básico de x=21, similar a las otras especies basales del Neotrópico.

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Section: Resultsmentioning

confidence: 99%

From Cuba to most of the neotropic: habenaria bicornis (orchidaceae) is widespread from Mexico to southeastern Brazil

Batista¹,

Proite²,

Carvalho³

et al. 2014

Lankesteriana

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“…It is generally accepted that 5S rDNA sites vary less in number and position than do 45S rDNA sites [68]. However, the Orchidaceae seems to be an exception, with their 5S rDNA sites being highly variable in number, position and sequence [25, 69, 70]. The duplication of the 5S rDNA site in H .…”

Section: Discussionmentioning

confidence: 99%

“…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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“…The chromosome preparation and the in situ hybridization followed the method described by Moraes et al (2012). Five SSR were used as probes: Aesfal.1 (monomorphic), Aesfal.8 (monomorphic in one region/polymorphic in another region), Aesfal.10 and Aesfal.13 (2 polymorphic regions each), and Aesfal.11 (polymorphic).…”

Section: Fluorescence In Situ Hybridization (Fish)mentioning

confidence: 99%

Microsatellite in Aeschynomene falcata (Leguminosae): diversity, cross-amplification, and chromosome localization

et al. 2014

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ABSTRACT. Aeschynomene falcata is an important forage species; however, because of low seed production, it is underutilized as forage species. Aeschynomene is a polyphyletic genus with a challenging taxonomic position. Two subgenera have been proposed, and it is suggested that Aeschynomene can be split in 2 genera. Thus, new markers, such as microsatellite sequences, are desirable for improving breeding programs for A. falcata. Based on transferability and in situ localization, these microsatellite sequences can be applied as chromosome markers in the genus Aeschynomene and closely related genera. Here, we report the first microsatellite library developed for this genus; 11 microsatellites were characterized, with observed and Microsatellite loci in Aeschynomene falcata expected heterozygosities ranging from 0.0000 to 0.7143 and from 0.1287 to 0.8360, respectively. Polymorphic information content varied from 0.1167 to 0.7786. The departure from Hardy-Weinberg equilibrium may have resulted from frequent autogamy, which is characteristic of A. falcata. Of the 11 microsatellites, 9 loci were cross-amplified in A. brevipes and A. paniculata and 7 in Dalbergia nigra and Machaerium vestitum. Five of these 7 cross-amplified microsatellites were applied as probes during the in situ hybridization assay and 2 showed clear signals on A. falcata chromosomes, ensuring their viability as chromosome markers.

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Chromosome studies in Orchidaceae: karyotype divergence in Neotropical genera in subtribe Maxillariinae

Cited by 22 publications

References 33 publications

From Cuba to most of the neotropic: habenaria bicornis (orchidaceae) is widespread from Mexico to southeastern Brazil

From Cuba to most of the neotropic: habenaria bicornis (orchidaceae) is widespread from Mexico to southeastern Brazil

Detecting Mechanisms of Karyotype Evolution in Heterotaxis (Orchidaceae)

Microsatellite in Aeschynomene falcata (Leguminosae): diversity, cross-amplification, and chromosome localization

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