Publicação
Ex situ collection of Limonium spp.: cytogenetic and reproductive characterization for the conservation of rare species
| Resumo: | Limonium algarvense is a halophyte species that grows in salthmarshes. There is a few knowledge about this species biology, specifically on cytogenetic variability and reproductive biology. This knowledge is fundamental to apply conservation methods since their habitat is being degraded by anthropic impacts. The present study aims were to collect data regarding characterization of cytogenetic and male function of L. algarvense. Geographical and demography data confirmed that this species ranges from Southwest Portugal, in Algarve, to southern Spain. Flow cytometric studies in L. algarvense populations revealed that triploid cytotypes, indicating a cytotype consistency and homogeny across a geographical gradient. Cytogenetic analysis in distinct plants originated from different natural populations confirmed that L. algarvense presents 2n=3x=25 chromosomes, as previously reported. Exploratory studies using combined GISH and FISH analysis didn’t allow identifying the putative progenitors of L. algarvense. Finally, micro-sporogenesis and gametogenesis analyses showed several abnormalities during male gametes formation like presence of chromosomes bridges and laggard chromosomes during meiosis, the formation of restitution nuclei and cytomixis. These anomalies led to the formation of nonreduced pollen grains with different morphology which showed low viability and low germination rate. The results present in this thesis provided useful data for a better understanding of this species reproductive biology which can contribute to design better strategies for this species conservation. |
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| Autores principais: | Conceição, Sofia Isabel Rodrigues da |
| Assunto: | FISH Geographical distribution GISH Karyotype L. algarvense Meiotic abnormalities Micro-sporogenesis and ametogenesis Polyploidy Anomalias meióticas Cariotipo Distribuição geográfica Micro-esporogénese e gametogénese Poliploidia |
| Ano: | 2015 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | Limonium algarvense is a halophyte species that grows in salthmarshes. There is a few knowledge about this species biology, specifically on cytogenetic variability and reproductive biology. This knowledge is fundamental to apply conservation methods since their habitat is being degraded by anthropic impacts. The present study aims were to collect data regarding characterization of cytogenetic and male function of L. algarvense. Geographical and demography data confirmed that this species ranges from Southwest Portugal, in Algarve, to southern Spain. Flow cytometric studies in L. algarvense populations revealed that triploid cytotypes, indicating a cytotype consistency and homogeny across a geographical gradient. Cytogenetic analysis in distinct plants originated from different natural populations confirmed that L. algarvense presents 2n=3x=25 chromosomes, as previously reported. Exploratory studies using combined GISH and FISH analysis didn’t allow identifying the putative progenitors of L. algarvense. Finally, micro-sporogenesis and gametogenesis analyses showed several abnormalities during male gametes formation like presence of chromosomes bridges and laggard chromosomes during meiosis, the formation of restitution nuclei and cytomixis. These anomalies led to the formation of nonreduced pollen grains with different morphology which showed low viability and low germination rate. The results present in this thesis provided useful data for a better understanding of this species reproductive biology which can contribute to design better strategies for this species conservation. |
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