Biologia reprodutiva e citogenética de espécies simpátricas de croton l. (Euphorbiaceae)

Detalhes bibliográficos
Autor(a) principal: Santos, Amanda de Souza
Data de Publicação: 2016
Tipo de documento: Dissertação
Idioma: por
Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
Texto Completo: https://repositorio.ufpb.br/jspui/handle/123456789/29694
Resumo: The Croton genus often presents itself in plant communities with several sympatric species without clear evidence of interspecific hybridization. Aiming to evaluate the existence of reproductive isolation barriers and potential hybridization between these species, it was evaluated different aspects of the reproductive biology of three sympatric species of Croton (C. heliotropiifolius, C. jacobinensis e C. urticifolius), in three different populations, by means of reproductive isolation mechanisms of pre-zygotic (flowering synchrony, floral biology and pollinators of each species), as post-zygotic (seed formation after controlled pollination experiments and cytogenetic analysis). We also analyzed the karyotypes of more 12 species of the genus Croton, surveying of all chromosome numbers previously known to the genus, and analyzed in a phylogenetic context in order to identify the ancestral basic number of the genus. The reproductive phenology of species varies among populations; however we observed a significant degree of synchrony floral species within populations. There are sharing of pollinators among them, being the most frequently: Apis sp., and Trigona sp., that visit flowers looking for nectar. They are self-compatible, with high fruit formation, no significant differences with regard to the formation of natural and intraspecific fruit. These results indicate weak pre-zygotic reproductive barriers for these sympatric species of Croton. Moreover, these species are inter-compatible with formation of interspecific fruits, suggesting the occurrence of an incomplete barrier post-zygotic reproductive isolation, allowing the formation of interspecific hybrids. The three species have chromosome number 2n = 20, with different patterns of heterochromatin. Karyotype differences in numbers and chromosomal structure usually constitute effective barriers to post-zygotic reproductive isolation. These results associated with the seed germination study in progress, suggest the need for further investigation in post-zygotic reproductive isolation barriers for these Croton species. Among the other species of the genus analyzed cytogenetically, most presented 2n = 20 except a population of Croton pulegioides (2n = 22) and C. limae (2n = ca.100). Five of the species analyzed had no previous records of chromosome counts: C. limae with 2n = ca.100, and C. rudolphianus, C. tricolor, C. adamantinus, and C. grewioides with 2n = 20. Most species presented two heterochromatic bands CMA+/DAPI– larger, located in the terminals of the short arms of a chromosome pair corresponding to RON. Whereas in species C. rudolphianus, C. urticifolius and C. sellowii, the RON was proximal. All species have distal regions of all chromosome arms (except the NORs), strongly stained with as DAPI. The analysis of molecular phylogeny combined with records of chromosome counts showed that the basic number x = 10 is the most likely for the genus. Although some species showed basic numbers different from x = 10, as C. xalapensis (x = 32), C. ruizianus (x = 8) and C. sarcopetalus (x = c.60), these numbers did not have significant values of Proportional Likelihoods to the ancestral basic number of the genus.
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spelling Biologia reprodutiva e citogenética de espécies simpátricas de croton l. (Euphorbiaceae)Fenologiaisolamento reprodutivoheterocromatinanúmero básicoCNPQ::CIENCIAS BIOLOGICASThe Croton genus often presents itself in plant communities with several sympatric species without clear evidence of interspecific hybridization. Aiming to evaluate the existence of reproductive isolation barriers and potential hybridization between these species, it was evaluated different aspects of the reproductive biology of three sympatric species of Croton (C. heliotropiifolius, C. jacobinensis e C. urticifolius), in three different populations, by means of reproductive isolation mechanisms of pre-zygotic (flowering synchrony, floral biology and pollinators of each species), as post-zygotic (seed formation after controlled pollination experiments and cytogenetic analysis). We also analyzed the karyotypes of more 12 species of the genus Croton, surveying of all chromosome numbers previously known to the genus, and analyzed in a phylogenetic context in order to identify the ancestral basic number of the genus. The reproductive phenology of species varies among populations; however we observed a significant degree of synchrony floral species within populations. There are sharing of pollinators among them, being the most frequently: Apis sp., and Trigona sp., that visit flowers looking for nectar. They are self-compatible, with high fruit formation, no significant differences with regard to the formation of natural and intraspecific fruit. These results indicate weak pre-zygotic reproductive barriers for these sympatric species of Croton. Moreover, these species are inter-compatible with formation of interspecific fruits, suggesting the occurrence of an incomplete barrier post-zygotic reproductive isolation, allowing the formation of interspecific hybrids. The three species have chromosome number 2n = 20, with different patterns of heterochromatin. Karyotype differences in numbers and chromosomal structure usually constitute effective barriers to post-zygotic reproductive isolation. These results associated with the seed germination study in progress, suggest the need for further investigation in post-zygotic reproductive isolation barriers for these Croton species. Among the other species of the genus analyzed cytogenetically, most presented 2n = 20 except a population of Croton pulegioides (2n = 22) and C. limae (2n = ca.100). Five of the species analyzed had no previous records of chromosome counts: C. limae with 2n = ca.100, and C. rudolphianus, C. tricolor, C. adamantinus, and C. grewioides with 2n = 20. Most species presented two heterochromatic bands CMA+/DAPI– larger, located in the terminals of the short arms of a chromosome pair corresponding to RON. Whereas in species C. rudolphianus, C. urticifolius and C. sellowii, the RON was proximal. All species have distal regions of all chromosome arms (except the NORs), strongly stained with as DAPI. The analysis of molecular phylogeny combined with records of chromosome counts showed that the basic number x = 10 is the most likely for the genus. Although some species showed basic numbers different from x = 10, as C. xalapensis (x = 32), C. ruizianus (x = 8) and C. sarcopetalus (x = c.60), these numbers did not have significant values of Proportional Likelihoods to the ancestral basic number of the genus.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESO gênero Croton frequentemente apresenta-se nas comunidades vegetais com diversas espécies simpátricas sem clara evidência de hibridização interespecífica. Com o objetivo de avaliar a existência de barreiras de isolamento reprodutivo e o potencial de hibridização entre essas espécies, foram avaliados diferentes aspectos da biologia reprodutiva de três espécies simpátricas de Croton (C. heliotropiifolius, C. jacobinensis e C. urticifolius), em três populações diferentes, por meio de mecanismos de isolamento reprodutivo pré-zigóticos (sincronia de floração, biologia floral e visitantes florais de cada espécie), como pós-zigóticos (formação de sementes após experimentos de polinização controlada e análises citogenéticas). Além disso, foram analisados também os cariótipos de mais 12 espécies do gênero, e levantados todos os números cromossômicos previamente conhecidos, e analisados num contexto filogenético, a fim de identificar o número básico ancestral. A fenologia reprodutiva das espécies variou entre as populações, porém foi possível observar um grau significativo de sincronia floral das espécies dentro das populações. Há o compartilhamento de polinizadores entre elas, sendo os visitantes mais frequentes: Apis sp., e Trigona sp., que visitam as flores à procura de néctar. São autocompatíveis, com formação elevada de frutos, sem diferenças significativas com relação à formação de frutos naturais e intraespecíficos. Esses resultados apontam fracas barreiras reprodutivas pré-zigóticas para essas espécies simpátricas de Croton. Por outro lado, essas espécies são intercompatíveis com formação de frutos interespecíficos, o que sugere a ocorrência de uma barreira de isolamento reprodutivo pós-zigótica incompleta, possibilitando a formação de híbridos interespecíficos. As três espécies também apresentam número cromossômico 2n = 20, mas com diferentes padrões de heterocromatina. Diferenças cariotípicas em número e estrutura cromossômica geralmente constituem eficientes barreiras de isolamento reprodutivo pós-zigótico. Esses resultados associados com o estudo da germinação das sementes ainda em andamento, sugerem a necessidade de uma melhor investigação nas barreiras de isolamento reprodutivo pós-zigotico para espécies simpátricas de Croton. Dentre as demais espécies do gênero analisadas citogeneticamente, a maioria também apresentou 2n = 20, exceto uma população de Croton pulegioides (2n = 22) e C. limae (2n = ca.100). Cinco das espécies analisadas não possuíam registros prévios de contagens cromossômicas: C. limae com 2n = ca.100, e C. rudolphianus, C. tricolor, C. adamantinus, e C. grewioides com 2n = 20. Todas as espécies apresentaram duas bandas heterocromáticas CMA+/DAPI– maiores, localizadas nos terminais dos braços curtos de um par cromossômico correspondente a RON, exceto C. rudolphianus, C. urticifolius e C. sellowii, que tiveram a RON proximal. Todas as espécies apresentaram regiões distais de todos os braços cromossômicos (exceto as RONs), fortemente corados com DAPI. As análises de filogenia molecular combinadas com registros de contagens cromossômicas mostraram que o número básico x = 10 é o mais provável para o gênero. Embora algumas espécies apresentem números básicos diferentes de x = 10, como C. xalapensis (x = 32), C. ruizianus (x = 8) e C. sarcopetalus (x = c.60), estes números não obtiveram valores significativos de Proportional Likelihoods para o número básico ancestral do gênero.Universidade Federal da ParaíbaBrasilCiências BiológicasPrograma de Pós-Graduação em BiodiversidadeUFPBFelix, Leonardo Pessoahttp://lattes.cnpq.br/0180466204127182Borges, Laís Angélica de Andrade Pinheirohttp://lattes.cnpq.br/7033738008294578Santos, Amanda de Souza2024-02-29T18:29:01Z2024-02-29T18:29:01Z2016-02-29info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesishttps://repositorio.ufpb.br/jspui/handle/123456789/29694porinfo:eu-repo/semantics/openAccessreponame:Biblioteca Digital de Teses e Dissertações da UFPBinstname:Universidade Federal da Paraíba (UFPB)instacron:UFPB2024-03-01T06:04:32Zoai:repositorio.ufpb.br:123456789/29694Biblioteca Digital de Teses e Dissertaçõeshttps://repositorio.ufpb.br/PUBhttp://tede.biblioteca.ufpb.br:8080/oai/requestdiretoria@ufpb.br|| diretoria@ufpb.bropendoar:2024-03-01T06:04:32Biblioteca Digital de Teses e Dissertações da UFPB - Universidade Federal da Paraíba (UFPB)false
dc.title.none.fl_str_mv Biologia reprodutiva e citogenética de espécies simpátricas de croton l. (Euphorbiaceae)
title Biologia reprodutiva e citogenética de espécies simpátricas de croton l. (Euphorbiaceae)
spellingShingle Biologia reprodutiva e citogenética de espécies simpátricas de croton l. (Euphorbiaceae)
Santos, Amanda de Souza
Fenologia
isolamento reprodutivo
heterocromatina
número básico
CNPQ::CIENCIAS BIOLOGICAS
title_short Biologia reprodutiva e citogenética de espécies simpátricas de croton l. (Euphorbiaceae)
title_full Biologia reprodutiva e citogenética de espécies simpátricas de croton l. (Euphorbiaceae)
title_fullStr Biologia reprodutiva e citogenética de espécies simpátricas de croton l. (Euphorbiaceae)
title_full_unstemmed Biologia reprodutiva e citogenética de espécies simpátricas de croton l. (Euphorbiaceae)
title_sort Biologia reprodutiva e citogenética de espécies simpátricas de croton l. (Euphorbiaceae)
author Santos, Amanda de Souza
author_facet Santos, Amanda de Souza
author_role author
dc.contributor.none.fl_str_mv Felix, Leonardo Pessoa
http://lattes.cnpq.br/0180466204127182
Borges, Laís Angélica de Andrade Pinheiro
http://lattes.cnpq.br/7033738008294578
dc.contributor.author.fl_str_mv Santos, Amanda de Souza
dc.subject.por.fl_str_mv Fenologia
isolamento reprodutivo
heterocromatina
número básico
CNPQ::CIENCIAS BIOLOGICAS
topic Fenologia
isolamento reprodutivo
heterocromatina
número básico
CNPQ::CIENCIAS BIOLOGICAS
description The Croton genus often presents itself in plant communities with several sympatric species without clear evidence of interspecific hybridization. Aiming to evaluate the existence of reproductive isolation barriers and potential hybridization between these species, it was evaluated different aspects of the reproductive biology of three sympatric species of Croton (C. heliotropiifolius, C. jacobinensis e C. urticifolius), in three different populations, by means of reproductive isolation mechanisms of pre-zygotic (flowering synchrony, floral biology and pollinators of each species), as post-zygotic (seed formation after controlled pollination experiments and cytogenetic analysis). We also analyzed the karyotypes of more 12 species of the genus Croton, surveying of all chromosome numbers previously known to the genus, and analyzed in a phylogenetic context in order to identify the ancestral basic number of the genus. The reproductive phenology of species varies among populations; however we observed a significant degree of synchrony floral species within populations. There are sharing of pollinators among them, being the most frequently: Apis sp., and Trigona sp., that visit flowers looking for nectar. They are self-compatible, with high fruit formation, no significant differences with regard to the formation of natural and intraspecific fruit. These results indicate weak pre-zygotic reproductive barriers for these sympatric species of Croton. Moreover, these species are inter-compatible with formation of interspecific fruits, suggesting the occurrence of an incomplete barrier post-zygotic reproductive isolation, allowing the formation of interspecific hybrids. The three species have chromosome number 2n = 20, with different patterns of heterochromatin. Karyotype differences in numbers and chromosomal structure usually constitute effective barriers to post-zygotic reproductive isolation. These results associated with the seed germination study in progress, suggest the need for further investigation in post-zygotic reproductive isolation barriers for these Croton species. Among the other species of the genus analyzed cytogenetically, most presented 2n = 20 except a population of Croton pulegioides (2n = 22) and C. limae (2n = ca.100). Five of the species analyzed had no previous records of chromosome counts: C. limae with 2n = ca.100, and C. rudolphianus, C. tricolor, C. adamantinus, and C. grewioides with 2n = 20. Most species presented two heterochromatic bands CMA+/DAPI– larger, located in the terminals of the short arms of a chromosome pair corresponding to RON. Whereas in species C. rudolphianus, C. urticifolius and C. sellowii, the RON was proximal. All species have distal regions of all chromosome arms (except the NORs), strongly stained with as DAPI. The analysis of molecular phylogeny combined with records of chromosome counts showed that the basic number x = 10 is the most likely for the genus. Although some species showed basic numbers different from x = 10, as C. xalapensis (x = 32), C. ruizianus (x = 8) and C. sarcopetalus (x = c.60), these numbers did not have significant values of Proportional Likelihoods to the ancestral basic number of the genus.
publishDate 2016
dc.date.none.fl_str_mv 2016-02-29
2024-02-29T18:29:01Z
2024-02-29T18:29:01Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/masterThesis
format masterThesis
status_str publishedVersion
dc.identifier.uri.fl_str_mv https://repositorio.ufpb.br/jspui/handle/123456789/29694
url https://repositorio.ufpb.br/jspui/handle/123456789/29694
dc.language.iso.fl_str_mv por
language por
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv Universidade Federal da Paraíba
Brasil
Ciências Biológicas
Programa de Pós-Graduação em Biodiversidade
UFPB
publisher.none.fl_str_mv Universidade Federal da Paraíba
Brasil
Ciências Biológicas
Programa de Pós-Graduação em Biodiversidade
UFPB
dc.source.none.fl_str_mv reponame:Biblioteca Digital de Teses e Dissertações da UFPB
instname:Universidade Federal da Paraíba (UFPB)
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collection Biblioteca Digital de Teses e Dissertações da UFPB
repository.name.fl_str_mv Biblioteca Digital de Teses e Dissertações da UFPB - Universidade Federal da Paraíba (UFPB)
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