• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 9
  • 3
  • 1
  • 1
  • Tagged with
  • 18
  • 11
  • 5
  • 5
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Experimental taxonomic studies on Caltha

Kootin-Sanwu, M. January 1966 (has links)
No description available.
2

Cytotaxonomy of the pocket mice, genus Peroganthus (Rodenta: Heteromyidae)

Patton, James L. January 1965 (has links)
No description available.
3

Citotaxonomia de espécies de Cactaceae ocorrentes no nordeste do Brasil

Castro, Juliana Pereira de 28 June 2012 (has links)
Submitted by Katiane Souza (katyane.souza@gmail.com) on 2016-06-05T18:18:33Z No. of bitstreams: 1 arquivototal.pdf: 2456208 bytes, checksum: c8d4f023af4b75f22897ab5d9a8cb347 (MD5) / Made available in DSpace on 2016-06-05T18:18:33Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2456208 bytes, checksum: c8d4f023af4b75f22897ab5d9a8cb347 (MD5) Previous issue date: 2012-06-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Were studied with CMA3 and DAPI fluorochrome staining techniques and in situ hybridization with 45S and 5S rDNA probes, representatives of the subfamilies Pesreskioideae, Opuntioideae and Cactoideae, 28 species of 14 genera, occurring mainly in the Northeast of Brazil, aiming to identify the heterochromatin distribution and location of rDNA sites in these species and their taxonomic implications. In the subfamilies Pereskioideae and Opuntioideae, chromosome numbers range from 2n = 22 in Pereskia aculeata, P. bahiensis, P. grandiflora (Pereskioideae), Brasilopuntia brasiliensis, Tacinga funalis and T. palmadora, 2n = 44 O. dillenii and 2n = 88 in O. ficus-indica (Opuntioideae). All species presented symmetric karyotypes and small chromosomes, with average sizes range from 1.94 μm in O. dillenii to 3.17 μm in P. aculeata. A pair of terminal CMA+ bands corresponding to the NORs occurred in all cytotypes in diploid and also O. dillenii (tetraploid), except in O. ficus-indica (octoploid) that exhibited two pairs of terminal bands. Additional CMA bands were observed in the interstitial region in the long arm of B. brasiliensis chromosome pair, while a variable number of pericentromeric bands were seen in three chromosome pairs in O. dillenii and in the majority of chromosomes in O. ficus-indica. The sites of 45S rDNA bands corresponded to the terminal CMA, while 5S sites were located in the interstitial region of a chromosome pair in P. aculeata, P. bahiensis and P. grandiflora, as in B. brasiliensis the 5S site was subterminal. In the subfamily Cactoideae, there were no previous chromosome records for Arrojadoa, Micrathocereus and Pilosocereus genera, as in Melocactus azureus, M. levitestatus, Stephanocereus luetzelburgii, Discocactus zehntneri, Hylocereus setaceus and Harrisia adscendens. In Arrojadoa, data for chromosome CMA+ banding pattern does not support inclusion of A. aurespina in A. rodantha limits. In Melocactus and Pilosocereus genera, there was a wide numeric variation of CMA+ pericentromeric bands, while CMA+ bands corresponding to the NORs were generally corresponding to the ploidy level. In species where 45S rDNA sites were mapped, there was a complete correspondence with the terminal CMA+ bands, and there were no additional 45S sites. Moreover, 5S sites were extremely variable in number and chromosomal location. 5S sites adjacent to 45S sites were characteristic of all Pilosocereus species analyzed. The variability in the number and distribution of CMA+ bands and 5S sites location were important cytotaxonomic characteristics in the studied taxa delimitation. / Foram estudadas através do bandeamento com os fluorocromos CMA3 e DAPI e hibridização in situ com sondas de DNAr 45S e 5S, representantes das subfamílias Pesreskioideae, Opuntioideae e Cactoideae, em 28 espécies de 14 gêneros, ocorrentes principalmente no Nordeste do Brasil, objetivando identificar a distribuição da heterocromatina e a localização dos sítios de DNAr nessas espéciese suas implicações taxonômicas. Para as subfamílias Pereskioideae e Opuntioideae, os números cromossômicos variaram de 2n = 22 em Pereskia aculeata, P. bahiensis, P. grandiflora (Pereskioideae), Brasilopuntia brasiliensis, Tacinga funalis e T. palmadora; 2n = 44 em O. dillenii e 2n = 88 em O. ficus-indica (Opuntioideae). Todas as espécies apresentaram cariótipos simétricos e cromossomos pequenos, com tamanhos médios variando de 1,94μm em O. dillenii a 3,17μm em P. aculeata. Um par de bandas CMA+ terminais correspondentes as RONs ocorreu em todos os citotipos diplóides e em O. dillenii (tetraplóide), exceto em O. ficus-indica (octaplóide) que exibiu dois pares de bandas terminais. Bandas CMA adicionais foram observadas na região intersticial do braço longo de um par cromossômico de B. brasiliensis, enquanto um número variável de bandas pericentroméricas foi visualizado em três pares cromossômicos de O. dillenii e na maioria dos cromossmos de O. ficus-indica. Os sítios de DNAr 45S corresponderam às bandas CMA terminais, enquanto os sítios 5S foram localizados na região intersticial de um par cromossômico de P. aculeata, P. bahiensis e P. grandiflora, enquanto em B. brasiliensis o sítio 5S foi subterminal. Na subfamília Cactoideae, não havia registros cromossômicos prévios para os gêneros Arrojadoa, Micrathocereus e Pilosocereus, nem para as espécies Melocactus azureus, M. levitestatus, Stephanocereus luetzelburgii, Discocactus zehntneri, Harrisia adscendens e Hylocereus setaceus. Em Arrojadoa, os dados cromossômicos para o padrão de bandas CMA+ não suportam a inclusão de A. aurespina nos limites de A. rodantha. Para os gêneros Melocactus e Pilosocereus, ocorreu uma ampla variação no número de bandas CMA+ pericentroméricas, enquanto as bandas CMA+ correspondentes as RONs, em geral foram correspondentes aos níveis de ploidia. Nas espécies onde os sítios de DNAr 45S foram mapeadas, houve total correspondência com as bandas CMA+ terminais, não tendo sido observados sítios 45S adicionais. Por outro lado, os sítios 5S foram bastante variáveis em número e localização cromossômica. Sítios 5S adjacentes aos sítios 45S foram característicos de todas as espécies analisadas de Pilosocereus. A variabilidade no número e distribuição de bandas CMA+ e localização de sítios 5S foram características citotaxonômicas importantes na delimitação dos táxons estudados.
4

Estudos Citogenéticos em Dorstenia L. (Moraceae)

BARRETO, L. M. 18 July 2016 (has links)
Made available in DSpace on 2018-08-01T22:57:27Z (GMT). No. of bitstreams: 1 tese_10051_Dissertação Final Lucas Mesquita Barreto.pdf: 1926946 bytes, checksum: 21145320a1a7d898eb87b86e37b7dd01 (MD5) Previous issue date: 2016-07-18 / Previous cytogenetic studies in Dorstenia mention that the species may have 24 to 72 chromosomes, and suggested a conserved chromosome number 2n = 32 for the Neotropic species. However, some information reported in the literature are dubious or insufficient to assess the potential of cytogenetic data to the better understand of systematics and evolution issues within this genus. Here, eight species of Neotropical Dorstenia had their karyotypes characterized, and the nuclear DNA content measured. Dorstenia bahiensis, D. cayapia, D. grazielae, D. hirta and D. turnerifolia had their karyotypes characterized and the DNA nuclear content measured for the first time. Morphological plant characters and morphometric data were submitted to cluster analysis, followed by a test of group sharpness, and ordination analysis, aiming to support the discussion about the potential of cytogenetic data to infrageneric systematic of Dorstenia. The species showed chromosome number of 2n = 32, varying in chromosomes morphology. The karyotypes least asymmetric were observed in Dorstenia elata, and the more asymmetric were registered in D. bahiensis and D. bonijesu. The 2C value ranged from 3.21 picograms (pg) D. bahiensis to 5.47 pg in D. arifolia. Morphologically similar species, like D. hirta and D. turnerifolia, grouped together based on morphometric data. The sharp groups based on morphometric data correspond to species circumscribed under the sections Dorstenia, Lecania and Emygodia, previously established based on the plant morphology. Our results supports that the chromosome number 2n = 32 is possible conserved in the Neotropical species of Dorstenia, and indicate the potential of cytogenetic data to the systematics of this genus.
5

Citotaxonomia e evolução cromossômica em Oligoryzomys (Rodentia, Sigmodontinae). / Citotaxonomy and chromosome evolution in Oligoryzomys (Rodentia, Sigmodontinae).

Nizo, Camilla Bruno Di 14 June 2013 (has links)
Oligoryzomys é o gênero mais especioso da tribo Oryzomyini e está amplamente distribuído na região Neotropical. O objetivo deste trabalho é contribuir para a citotaxonomia e investigar a evolução cromossômica no gênero. Foram analisados 117 exemplares pertencentes às espécies: O. flavescens (2n=64-66, NF=66), O. fornesi (2n=62, NF=64), O. microtis (2n=64, NF=64), O. moojeni (2n=70, NF=72), O. nigripes (2n=62, NF=78-82), O. stramineus (2n=52, NF=68) e Oligoryzomys sp. A (2n=70, NF=72). As seis primeiras possuem cariótipos espécie-específicos e, dessa forma, reiteramos a importância da informação citogenética para a citotaxonomia. A pintura cromossômica comparativa (Zoo-FISH) com sondas de O. moojeni revelou hibridação em 29 segmentos autossômicos em O. fornesi; 30 em O. microtis; 31 em O. nigripes; e 32 em O. rupestris e Oligoryzomys sp. 2. Os resultados mostraram uma extensa reorganização genômica na evolução cromossômica do gênero, decorrente de fissões, fusões em tandem, rearranjos Robertsonianos e perda/inativação, surgimento ou reposicionamento de centrômero. / Oligoryzomys is the most specious genus within the tribe Oryzomyini and it is distributed throughout Neotropical region. This work aims to contribute to citotaxonomy and to investigate the chromosomal evolution of the genus. A total of 117 individuals were cytogenetically analysed, and they belong to the species: O. flavescens (2n=64-66, FN=66), O. fornesi (2n=62, FN=64), O. microtis (2n=64, FN=64), O. moojeni (2n=70, FN=72), O. nigripes (2n=62, FN=78-82), O. stramineus (2n=52, FN=68), and Oligoryzomys sp. A (2n=70, FN=72). The first six species possess species-specific karyotypes, and therefore we emphasize the importance of cytogenetic studies for citotaxonomy. Comparative chromosome painting (Zoo-FISH) with O. moojeni probes hybridized to 29 segments on metaphases of O. fornesi, 30 on O. microtis, 31 on O. nigripes, and 32 on O. rupestris and Oligoryzomys sp. 2. The results showed an extensive genomic reshuffling, due to fissions, tandem and Robertsonian fusions, loss/inactivation or repositioning of centromeres.
6

Cytotaxonomic Studies On The Genus Salvia (labiatae) In Turkey

Inanc Gok, Tugba 01 December 2009 (has links) (PDF)
The genus Salvia L. is significantly important with regard to both its worldwide distribution and usage areas including food, medical and perfumary industries. In this current study, it is targeted to address the chromosome numbers and karyomorphology of the ten species and one variety of the genus Salvia. All of the eleven taxa examined in this study are economically significant and nine of these are endemic to Turkey. To define the chromosome numbers and karyomorphology of these eleven taxa somatic chromosomes of the each were examined. Mitotic metaphase chromosomes were obtained from root meristems of germinating seeds, which were pre-treated in &amp / #945 / -bromonaphtalene at 4&ordm / C for 16 h, then fixed in Carnoy solution (3 parts of ethanol: 1 parts of glacial acetic acid) at 4&ordm / C for 24h and stored in 70 % ethanol. Fixed root tips were stained in 2 % aceto-orcein and squashed in a drop of 45 % acetic acid. Long arm, short arm, total length of the each chromosomes were measured / relative length, arm ratio, centromeric index of the each chromosome were calculated. Karyogram and haploid idiograms were drawn by computer-aided analysis programme (Bs200pro). A cluster analysis of the karyotype data was carried out to examine karyotype similarity among taxa. Somatic chromosome numbers have been counted as 2n=2x=14 for the endemic taxa S. divaricata Montbret &amp / Aucher, S. euphratica Montbret &amp / Aucher ex Bentham (var. leiocalycina (Rech. fil.) Hedge) and S. recognita Fisch. &amp / Mey. / 2n=2x=14-1B for Salvia rosifolia Sm. / 2n=20 for S. longipedicellata Hedge, S. vermifolia Hedge &amp / Hub.-Mor. and S. yosgadensis Freyn &amp / Bornm. / 2n=2x=22 for S. aethiopis L., S. cilicica Boiss. &amp / Kotschy, S. hypargeia Fisch. &amp / Mey. and 2n=2x=32 for S. napifolia Jacq. respectively. In general, the chromosomes are short with median and submedian centromeres. The current study is essential for being the first report about chromosome numbers and karyomorphology of the six endemic taxa, namely S. divaricata, S. euphratica var. leiocalycina, S. longipedicellata, S. rosifolia, S. vermifolia and S. yosgadensis. Moreover, in spite of the chromosome numbers of S. aethiopis, S. cilicica, S. hypargeia and S. recognita are known, this research is the first study for their karyomorphologies.
7

Bazı Lathyrus L. türlerinin karyolojik özellikleri /

Yıldırım, Bekir. Genç, Hasan. January 2007 (has links) (PDF)
Tez (Yüksek Lisans) - Süleyman Demirel Üniversitesi, Fen Bilimleri Enstitüsü, Biyoloji Anabilim Dalı, 2007. / Kaynakça var.
8

Citotaxonia e aspectos evolutivos de especies de Hoffmannsegella H.G.Jones (Orchidaceae)

Costa, Julia Yamagishi 06 September 2006 (has links)
Orientador : Eliana Regina Forni-Martins / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-06T21:09:05Z (GMT). No. of bitstreams: 1 Costa_JuliaYamagishi_D.pdf: 4268702 bytes, checksum: 5ceb4f75d53e52eb1a73e6e26179508e (MD5) Previous issue date: 2006 / Resumo: Dentro da família Orchidaceae, composta por cerca de 25.000 espécies, o gênero Hoffmannseggella (antiga seção Parviflorae do gênero Laelia Lindl.) é composto por espécies rupícolas, endêmicas da Cadeia do Espinhaço/MG. Estudos sugerem uma evolução rápida para o gênero, com a transição do hábito epifítico para o rupícola, mudança de polinizadores e eventos de hibridização e poliploidia como os principais mecanismos evolutivos envolvidos na origem das espécies de Hoffmannseggella. Estudos cromossômicos prévios haviam sugerido o número básico de x=20 para o gênero, com alta incidência de poliplóides. No presente trabalho, foram obtidas contagens cromossômicas para dez espécies: H. angereri n=20/2n=40, H. bradei n=20-21/2n=40, H. briegeri 2n=80, H. caulescens 2n=80, H. cinnabarina 2n=40, H. crispata n=20, H. fournieri n=20/2n=40, H. liliputana 2n=40/60, H. rupestris n=40/2n=80 e 2n=40 e H. viridiflora 2n=44. Foi observada aneussomatia em células de meristema radicular em H. briegeri (2n=80) e H. rupestris (2n=80), ocorrência de citótipos em H. rupestris (2n=40/80) e anormalidades meióticas em várias espécies, com presença de monovalentes, disjunção adiantada de bivalentes e possíveis tetravalentes nas espécies poliplóides. Por ocorrerem em sincronopatria, apresentarem alta similaridade morfológica e pelas características cromossômicas, é provável que H. viridiflora tenha se originado por aneuploidia a partir de H. bradei. Através dos procedimentos de bandamentos C, CMA/DA/DAPI e DAPI/AMD, foi possível observar grandes diferenças entre os cariótipos das espécies H. angereri, H. bradei, H. briegeri, H. caulescens, H. fournieri, H. liliputana e H. rupestris. Em geral, as espécies apresentaram grande número de bandas C (predominantemente centroméricas e subteloméricas), poucas bandas CMA/DA+ (subteloméricas), e grande variação no número de bandas DAPI/AMD+ (predominantemente teloméricas). Apenas H. bradei apresentou somente duas bandas heterocromáticas, uma CMA/DA+ DA/DAPI- e uma DAPI/AMD+ e H. briegeri apresentou polimorfismo para bandas CMA/DA/DAPI. Com relação aos sítios 45S de DNAr, os resultados foram uniformes, sendo que as espécies diplóides, com 2n=40, apresentaram dois sítios, enquanto as espécies poliplóides, com 2n=80, apresentaram 4 sítios / Abstract: Inside Orchidaceae, composed of almost 25,000 species, Hoffmannseggella H.G.Jones (previous genus Laelia Lindl., section Parviflorae) is characterized by rupiculous species, endemic to the Espinhaço Range/ MG. Previous studies suggested an explosive evolution of the genus, with transition from epiphytic to rupiculous habitat, changes on pollinator specificity and events of hibridization and polyploidy as the main evolutionary mechanisms that originated Hoffmannseggella species. Chromosome data from literature suggested the base number of x=20 for the genus, with high incidence of polyploids. The present work presents chromosome counts for ten species: H. Angereri n=20/2n=40, H. bradei n=20-21/2n=40, H. briegeri 2n=80, H. caulescens 2n=80, H. cinnabarina 2n=40, H. crispata n=20, H. fournieri n=20/2n=40, H. liliputana 2n=40/60, H. rupestris n=40/2n=80 and 2n=40 and H. viridiflora 2n=44. We observed aneussomaty on root meristematic cells of H. briegeri (2n=80) and H. rupestris (2n=80), two distinct cytotypes of H. rupestris (2n=40 and 2n=80) and meiotic abnormalities in several species, like monovalents, early disjunction of bivalents and putative tetravalents on polyploid species. Because they are found sinchronopatric, with high morphological and chromosomal similarity, we suggest that H. viridiflora (2n=44) is an aneuploid derived from H. bradei (2n=40). With C, CMA/DA/DAPI and DAPI/AMD banding techniques, we observed great differences among H. angereri, H. bradei, H. briegeri, H. caulescens, H. fournieri, H. liliputana e H. rupestris. With exception of H. bradei, that presented only two heterochromatic, one CMA/DA+ DA/DAPI- and one DAPI/AMD+ bands, all species presented a high number of C-bands (mainly centromeric and subtelomeric), few CMA/DA+ bands (subtelomeric), and great numeric differences of DAPI/AMD+ bands (mainly telomeric). We also observed, in H. briegeri, a polymorphism of CMA/DA/DAPI bands. The hybridization sites of 45S rDNA were uniform among species, with diploid species (2n=40) presenting two hybridization signals and polyploid species (2n=80) presenting four signals / Doutorado / Doutor em Biologia Vegetal
9

Cytotaxonomy, classification and phylogeny of African Carventinae (Heteroptera: aradidae)

Jacobs, Dawid Hermanus 29 May 2006 (has links)
The southern African species of the Aradidae subfamily Carventinae are revised, resuhing in the recognition of 7 genera, 24 species and 10 subspecies (excluding the nominal ones). Of these, 4 genera, 18 species and 10 subspecies are described as new. A neotype is designated for Dundocoris natalensis. Keys to the genera and species are given. Scanning electron photomicrographs of the dorsal and ventral aspects and external genitalia are provided for all the species. The cytogenetics of the group are discussed and idiograrns, based on chromosome area measurements, and photomicrographs of meiotic stadia (mostly metaphase I and metaphase II) are presented for all but one species. The chromosome numbers of the species vary between 2n = 7XY1Y2 and 2n = 32XY and XY, X1X2Y and XY1Y2 sex chromosome systems occur. Muhiple sex chromosome systems that originated from autosome-sex chromosome fusions are described for the first time in the Heteroptera. A unique case where two homologous autosomes have fused with the X- and Y -chromosomes respectively, is reported. Karyotype evolution and the origin of the different chromosome numbers are discussed and hypotheses presented. Pseudoploidy, fusions and to a lesser extent fragmentation, have played the major role in the karyotype evolution of the Carventinae. The cytogenetics of the other subfamilies of the Aradidae are briefly discussed and illustrated. It is argued that the ancestral chromosome number for the Carventinae and Aradidae (and therefore also the Pentatomorpha) is 2n = 14XY. The morphological and cytogenetic data are integrated in the classification of the Carventinae and several of the subspecies are based on chromosome number differences. The homeostatic genetic species concept is proposed and its application to the Carventinae is discussed. Phylogenies for the genera and species are proposed. The text is accompanied by more than 540 figures and more than 60 tables. / Thesis (DPhil (Entomology))--University of Pretoria, 2007. / Zoology and Entomology / unrestricted
10

Citotaxonomia e evolução cromossômica em Oligoryzomys (Rodentia, Sigmodontinae). / Citotaxonomy and chromosome evolution in Oligoryzomys (Rodentia, Sigmodontinae).

Camilla Bruno Di Nizo 14 June 2013 (has links)
Oligoryzomys é o gênero mais especioso da tribo Oryzomyini e está amplamente distribuído na região Neotropical. O objetivo deste trabalho é contribuir para a citotaxonomia e investigar a evolução cromossômica no gênero. Foram analisados 117 exemplares pertencentes às espécies: O. flavescens (2n=64-66, NF=66), O. fornesi (2n=62, NF=64), O. microtis (2n=64, NF=64), O. moojeni (2n=70, NF=72), O. nigripes (2n=62, NF=78-82), O. stramineus (2n=52, NF=68) e Oligoryzomys sp. A (2n=70, NF=72). As seis primeiras possuem cariótipos espécie-específicos e, dessa forma, reiteramos a importância da informação citogenética para a citotaxonomia. A pintura cromossômica comparativa (Zoo-FISH) com sondas de O. moojeni revelou hibridação em 29 segmentos autossômicos em O. fornesi; 30 em O. microtis; 31 em O. nigripes; e 32 em O. rupestris e Oligoryzomys sp. 2. Os resultados mostraram uma extensa reorganização genômica na evolução cromossômica do gênero, decorrente de fissões, fusões em tandem, rearranjos Robertsonianos e perda/inativação, surgimento ou reposicionamento de centrômero. / Oligoryzomys is the most specious genus within the tribe Oryzomyini and it is distributed throughout Neotropical region. This work aims to contribute to citotaxonomy and to investigate the chromosomal evolution of the genus. A total of 117 individuals were cytogenetically analysed, and they belong to the species: O. flavescens (2n=64-66, FN=66), O. fornesi (2n=62, FN=64), O. microtis (2n=64, FN=64), O. moojeni (2n=70, FN=72), O. nigripes (2n=62, FN=78-82), O. stramineus (2n=52, FN=68), and Oligoryzomys sp. A (2n=70, FN=72). The first six species possess species-specific karyotypes, and therefore we emphasize the importance of cytogenetic studies for citotaxonomy. Comparative chromosome painting (Zoo-FISH) with O. moojeni probes hybridized to 29 segments on metaphases of O. fornesi, 30 on O. microtis, 31 on O. nigripes, and 32 on O. rupestris and Oligoryzomys sp. 2. The results showed an extensive genomic reshuffling, due to fissions, tandem and Robertsonian fusions, loss/inactivation or repositioning of centromeres.

Page generated in 0.0498 seconds