Contribution to the karyological study of the genus Calendula L. (Asteraceae)

• Autor(a) principal: Fidalgo, Maria Eduarda Pires Marques
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/39246
• topic: Calendula; Karyotype; Hibrid; Citogenetics; Ideogram

This work is a contribution to the cytogenetic study of the genus Calendula, in which Calendula tripterocarpa Rupr., Calendula stellata Cav. and two species not yet identified, designated Calendula sp. 3067 and Calendula sp. 3339, were analyzed. For the first two, it was confirmed that they have 2n=30 and 2n=14, respectively, as reported in the literature, while for the last two, the karyotypes were determined to be 2n=88 and 2n=18, respectively. Germination rates were measured and the germination protocol was improved. The amount of nuclear DNA was measured and compared between species and, additionally, ideograms were performed, and asymmetry indices were calculated for Calendula sp. 3339 and Calendula stellata. The values measured for the karyotype of Calendula sp. 3067 indicate that this is probably a hybrid resulting from the cross between Calendula tripterocarpa and Calendula stellata that underwent subsequent duplication. Additionally, a karyotypic formula for Calendula stellata and Calendula sp. 3339 is proposed, and the karyotype asymmetry indices were analyzed and compared, which suggest an evolutionary link between the two species.