Types of Resting Nuclei in Orchidaceae

Tanaka, Ryutaro

doi:10.15281/jplantres1887.84.118

Cited by 137 publications

(117 citation statements)

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“…There exists a general tendency to preserve only one type of interphase nucleus for the entire genus, or for a higher taxonomic category, as it is done with Rutinaceae, in the Aurantioideae subfamily, and in most Mirtaceae genera, such as Laureaceae, Ananaceae, Magnoliaceae, Orchidaceae, etc (Guerra 1985). In orchids, Tanaka (1971) described 5 different types of interphase nuclei, based on the observation of 115 species from 52 genera. The occurrence of more than one type of interphase nucleus, inside only one Orchidaceae genus, has also been described in Habenaria (Félix andGuerra 1998), Cyrtopodium andCatasetum (Guerra 2000).…”

Section: Resultsmentioning

confidence: 99%

Characterization of the Species Epidendrum cinnabarium Salzm. (Epidendroideae: Orchidaceae) Occurring in Dunas Do Abaete-Salvador, Ba-Brasil

2006

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Summary This work has as its purpose to analyze the Epidendrum cinnabarium species, which can be found within the "Environment Protection Area of Abaeté Lakes and Dunes" ("Área de Proteção Ambiental das Lagoas e Dunas de Abaeté")-APA/Abaeté, Salvador, Bahia State-Brazil. As for the cytogenetic aspects it aims at determining the chromosome number, on the ploidy level, the types of interphasic nuclei, and at evaluating the possible meiotic irregularities of this species. In the mitotic analysis, radicular meristem has been pre-treated with 8-hydroxyquinoline and colored with aid of the Feulgen method. In order to carry out the meiotic analysis, microsporocytes were prepared by squashing and staining with 0.2% propionic carmine. The results showed 2nХ240, suggesting the occurrence of poliploidy, an interphasic nucleus of the semi-reticulate type with the presence of chromocenters displaying a variable number, besides an irregular meiotic behavior, with the presence of laggard chromosomes and laggard chromatids, as well eventually anaphasic bridges and a low percentage of abnormal tetrads.Key words Orchidaceae, Epidendrum, Chromosome.The Epidendrum Linnaeus genus has a vast distribution in America, from North Carolina, in the United States, to Argentina, whereas in Brazil it is well represented by several endemical species. These orchids are extremely variabale in what concerns the habitat requirements, being mainly an epiphyte species, in spite of the fact that some are lithophytes, and others are terrestrial. The number of species in this genus is quite variable, since it used to include some species which are now classified under such genera, as Encyclia, Osterdella, Psychilus, Nanodes, among others. In the Epidendrum genus, the number of estimated species approaches 900 (Philips and Hill 1988), but the cytogenetical knowledge about this Epidendrum genus is still a limited one.From the 900 already known species, there are registrations of chromosome countings for only 40 of them, which represents only 4.4% of the genus. The somatic number varies form 2nϭ24 to 2nϭ240 (Moore 1973, Golldblat 1981, 1985, 1988, Golldblat and Johnson, 1991, 1994, 1996, 1998, Blumenschein 1957, Tanaka and Kamemoto 1984, Félix and Guerra, 2000, and the majority of the taxons has 2nϭ40. The presence of nϭ20, in many representatives, suggests that the basic primary number is xϭ20.E. cinnabarium, originary from Brazil, is basically characterized by the presence of elongated stems without pseudobulbs, with flowers developing on a terminal spike. With the objective to contribute for the cytogenectic knowledge of this species, this work aims both at determining the number of chromosomes as well as the ploidiy level, at analyzing the types of interphasical nuclei, as

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Section: Resultsmentioning

confidence: 99%

Characterization of the Species Epidendrum cinnabarium Salzm. (Epidendroideae: Orchidaceae) Occurring in Dunas Do Abaete-Salvador, Ba-Brasil

2006

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“…Crassification for the chromosome types at resting and mitotic prophase stages followed Tanaka (1971Tanaka ( , 1977. Crassification for the chromosome types by the centromeric positions at mitotic metaphase stage followed Levan et al (1964).…”

Section: Observation Of Chromosomesmentioning

confidence: 99%

A comparison of chromosome characters in three species of Thymus (Lamiaceae) collected in Russia and Mongolian Altai

et al. 2008

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ABSTRACT. Characters of the resting, the mitotic prophase and metaphase chromosomes in three species of Thymus were studied. The species studied had commonly resting chromosomes of the complex chromocenter type and mitotic prophase chromosomes of the proximal type. Thymus mongolicus showed the chromosome numbers of 2n=26 and 27 and T. przewalskii and T. roseus showed the chromosome number of 2n=26. The chromosome number of 2n=26 for T. przewalskii and that of 2n=27 for T. mongolicus were reported here for the first time and that of 2n=26 for T. roseus and T. mongilicus verified the previous reports. The chromosome number of 2n=27 for T. mongolicus seemed to have one B-chromosome as 2n=26+1B with respect to the existence of a peculiar heteropycnotic body at resting stage and high pollen stainability. Three species were commonly placed in the diploid level if the basic chromosome numbers of x=13 was accepted. Their karyotypes at mitotic metaphase were quite similar to each other regarding chromosome sizes, chromosome types according to the centromeric position and mono-modality of chromosome lengths from the longest to the shortest chromosomes except for satellite sizes. Thymus L., the Lamiaceae (Labiatae) is small subshrub plants and consists of approximately 400 species (Willis 1982). They are distributed in the temperate zone of the Eurasian continent, mainly in the Mediterranean region (Willis 1982) and grow in diabase, serpentine and calcareous rocks, limestone, in cracks rocks, on a bank, steppe, on sandy soils, xerophilous grassland, on loessic slopes and along road sides. Thymus has always been taxonomically problematic group and views concerning the taxonomic definition of the forms are extremely varied. It produces some natural hybrids. Plants of the genus is often cultivated and propagate to extract the aromatic ethereal oil and flavouring. KEYWORDS:The first cytological observation in Thymus was counting and documenting the chromosome number: 2n=24 in T. serpyllum reported by Löve and Löve (1942). Then, many more researchers have found at least 50 different chromosome numbers from 2n=14 of T. seravschanicus to 2n=90 of T. zygioides var. lycaonicus. They also have found aneuploidy in T. longedentatus as well as autoploidy in about 170 taxa included 139 species, 17 subspecies, 12 varieties and two hybrids by Löve and Löve (1942), Saaremaa (1947), Jalas (1948), Jalas and Kaleva (1966Kaleva ( , 1967, Trela-Sawicka (1968, 1970, Gogina and Svetozarova (1972), Gurzenkov (1972), Lee (1972), Jalas and Uotila (1976), Krogulevich (1978), Arrigonia et. al. (1980, Bir and Saggoo (1980), ElenaRoselló (1980), Morales Valverde (1980, 19861986a, 1990, Astanova (1981), Hruška and Bellomaria (1982), Fernandes and Leitao (1984), Funamoto et. al. (1993), Markova and Goranova (1994, Mártonfi and Mártonfiova (1996), Boscaiu et al. (1998), Tahiri et al. (1998, Constantinidis et al. (2002). Jalas (1948), Jalas and Kalev (1967) and Mártonfi and Mártonfiova (1996) and Mehrpure et al. (2002) have discussed chromosomal evolutio...

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“…The interphase nuclei varied from the simple to complex chromocenter types, according to the classification of Tanaka (1971). In Dichaea panamensis, Catasetum barbatum, C. discolor, C. luridum, Dipteranthus duchii, Dipteranthus sp., Cyrtopodium blanchetii, Gongora quinquenervis, Oeceoclades maculata, Trigonidium acuminatum and T. obtusum, along with all the species of In some other families, analysis of the chromatin organization in interphase nuclei has contributed to an understanding of the genomic diversification, independent of number and chromosome morphology (Morawetz, 1986;Röser, 1994).…”

Section: Psygmorchis Pusilla Rodriguezia Bahiensis and Trichocentrmentioning

confidence: 99%

Cytogenetics and cytotaxonomy of some Brazilian species of Cymbidioid orchids

Félix

Guerra

2000

Genet. Mol. Biol.

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The Cymbidioid phylad presents the widest chromosome number variation among orchids, with records varying from 2n = 10 in Psygmorchis pusilla to 2n = 168 in two species of Oncidium. In the present work, a total of 44 species were studied belonging to 20 Cymbidioid genera, as a contribution to clarifying the karyological evolution of the group. All the plants investigated were collected in Brazil, mainly in the northeast region. The chromosome variation found was similar to that previously registered in the literature. Chromosome numbers observed were: 2n = 54 (subtribe Eulophiinae), 2n = 44, 46, 92 (subtribe Cyrtopodiinae), 2n = 54, ca. 108 (subtribe Catasetinae), 2n = 52, ca. 96 (subtribe Zygopetalinae), 2n = 40, 80 (subtribe Lycastinae), 2n = 40, 42 (subtribe Maxillariinae), 2n = 40 (subtribe Stanhopeinae), 2n = 56 (subtribe Ornithocephalinae), and 2n = 12, 20, 30, 36, 42, 44, 56, 112, ca. 168 (subtribe Oncidiinae). Interphase nuclei varied widely from simple chromocenter to complex chromocenter types, with no apparent cytotaxonomic value. In the genera Catasetum and Oncidium, the terrestrial and lithophytic species presented higher ploidy levels than the epiphytic species, suggesting a higher adaptability of the polyploids to those habitats. The primary base number x = 7 seems to be associated to the haploid chromosome numbers of most Cymbidioid groups, although n = 7 was observed only in two extant genera of Oncidiinae. For each tribe, subtribe and genus the probable base numbers were discussed along with the possible relationships to the primary base number x 1 = 7 admitted for the whole phylad.

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Types of Resting Nuclei in Orchidaceae

Cited by 137 publications

References 2 publications

Characterization of the Species Epidendrum cinnabarium Salzm. (Epidendroideae: Orchidaceae) Occurring in Dunas Do Abaete-Salvador, Ba-Brasil

Characterization of the Species Epidendrum cinnabarium Salzm. (Epidendroideae: Orchidaceae) Occurring in Dunas Do Abaete-Salvador, Ba-Brasil

A comparison of chromosome characters in three species of Thymus (Lamiaceae) collected in Russia and Mongolian Altai

Cytogenetics and cytotaxonomy of some Brazilian species of Cymbidioid orchids

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