Taxonomy, phylogeny and reproductive ecology of Gentiana lutea L.

Rossi, Martina (2012) Taxonomy, phylogeny and reproductive ecology of Gentiana lutea L., [Dissertation thesis], Alma Mater Studiorum Università di Bologna. Dottorato di ricerca in Biodiversità ed evoluzione, 24 Ciclo. DOI 10.6092/unibo/amsdottorato/4740.
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Abstract

This research focuses on taxonomy, phylogeny and reproductive ecology of Gentiana lutea. L.. Taxonomic analysis is a critical step in botanical studies, as it is necessary to recognize taxonomical unit. Herbarium specimens were observed to assess the reliability of several subspecies-diagnostic characters. The analysis of G. lutea genetic variability and the comparison with that of the other species of sect. Gentiana were performed to elucidate phylogenetic relationships among G. lutea subspecies and to propose a phylogenetic hypothesis for the evolution and the colonization dynamics of the section. Appropriate scientific information is critical for the assessment of species conservation status and for effective management plans. I carried out field work on five natural populations and performed laboratory analyses on specific critical aspects, with special regard to G. lutea breeding system and type and efficiency of plant-pollinator system. Bracts length is a reliable character to identify subsp. vardjanii, however it is not exclusive, hence to clearly identify subsp. vardjanii, other traits have to be considered. The phylogenetic hypotheses obtained from nuclear and chloroplast data are not congruent. Nuclear markers show a monophyly of sect. Gentiana, a strongly species identity of G. lutea and clear genetic identity of subsp. vardjanii. The little information emerging from plastid markers indicate a weak signal of hybridization and incomplete sorting of ancestral lineages. G. lutea shows a striking variation in intra-floral dichogamy probably evolved to reduce pollen-stigma interference. Although the species is partially self-compatible, pollen vectors are necessary for a successful reproduction, and moreover it shows a strong inbreeding depression. G. lutea is a generalist species: within its spectrum of visitors is possible to recognize "nectar thieves" and pollinators with sedentary or dynamic behaviour. Pollen limitation is frequent and it could be mainly explained by poor pollen quality.

Abstract
Tipologia del documento
Tesi di dottorato
Autore
Rossi, Martina
Supervisore
Dottorato di ricerca
Scuola di dottorato
Scienze biologiche, biomediche e biotecnologiche
Ciclo
24
Coordinatore
Settore disciplinare
Settore concorsuale
Parole chiave
Taxonomy, Phylogeny, Reproductive Ecology, Dichogamy, Gentiana lutea, section Gentiana
URN:NBN
DOI
10.6092/unibo/amsdottorato/4740
Data di discussione
17 Maggio 2012
URI

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