6. Conclusions
The present investigation was conducted in the frame of the “Socrates Project” in the Faculty of Biology of Patras University, Greece, during nine months of the academic year 2003-2004, in order to elucidate the cytotaxonomical aspects of some geophytes of Greece.
The taxa studied belong to different families of the order Asparagales, superorder Liliiflorae of the Monocots, according to Dahlgren (1985); these families are Alliaceae, Hyacinthaceae and Amaryllidaceae.
The plants of each unit have been collected in different areas of Greece, including the Ionian Islands (Zakynthos, Kefalonia, Lefkas), Peloponnese, and the eastern Greek mainland.
All the taxa studied are spontaneous in Greece except one, Amaryllis belladonna, present in the Greek flora as naturalized component. The other units investigated have a relatively wide diffusion mainly in Mediterranean countries, except Allium ionicum which is a Greek endemic with a narrow distribution in the Ionian Islands.
The present research has allowed to determinate the chromosome number and the idiogram with the corresponding idiogrammatic formula of some populations of the taxa in object.
The chromosome numbers obtained are reported below:
Allium ionicum Brullo & Tzanoud., 2n=16 Allium paniculatum L., 2n=16
Allium guttatum Steven ssp. sardoum (Moris) Stearn, 2n=16+1B Muscari comosum (L.) Miller, 2n=18
Muscari commutatum Guss., 2n=18
Amaryllis belladonna L., 2n=22
The basic chromosome number and the general karyotype complement obtained resulted in agreement with many authors, for plants mainly from the Mediterranean area.
Nevertheless, slight differences have been observed in some karyotype details in respect to other authors, for instance the position of the secondary nucleolar constrictions in Allium ionicum; some differences resulted between the two populations here studied and in respect to populations investigated by other authors.
Anyway the differences here evidenced can be explained in terms of variability of the karyotype within a taxon, often as a response to particular ecological factors.
The Allium paniculatum and Allium guttatum karyotypes found have brought a contribute to the knowledge of cytogeographical distribution pattern of Allium in Greece, which allows to establish plants migration routes and evolution pattern.
Muscari comosum has confirmed the well known structural heterozygosity present in the second chromosome pair, bringing a contribute with regard to the type of this polymorphism and its adaptative role.
Muscari commutatum has also confirmed the data existing with regards to the position of the satellites and the general chromosome morphology.
At last, Amaryllis belladonna has allowed making considerations on the variable levels of ploidy in cultivated or naturally spreading plants.
The karyological studies continue to be basic elements to solve biosystematic, taxonomic and evolutionary problems.
In Greece, particularly in the Institute of Botany of Patras, a group of research has been studying, for many years, the nature of the chromosomic complement and the ploidy level of numerous geophytes populations, as well as the cytogeography of controversial taxa with difficult taxonomical circumscription.
The present study represents a contribute to these matters and also to the knowledge of the biodiversity of the Balkan Peninsula and its islands, in prospect of their environmental protection and revaluation.
Indeed the Hellenic Flora contains a large number of threatened species. This is
due, first of all, to the particular geomorphologic characteristics of the Greek
territory. There is a considerable presence of habitats, like coastal cliffs and sandy
beaches, in which the ecosystem succession cannot reach by nature a climax
community. And in these places many plant species included in the Red Lists grow often in small scattered populations, where they are threatened by extinction due to the anthropic influence such as the development of the tourism industry.
As the Hellenic Red Data Book reports, for many of these threatened species no effective protection measures have been taken, and where the conservation in the site of plant occurrence doesn’t seem feasible, the species should be cultivated in botanical gardens, which are very scarce in Greece.
On the other side, there are relatively stable environments in which the ecosystem succession has been arrested by human impact before reaching its equilibrium;
anyway these places contribute to the floristic richness. An example is the low Mediterranean scrub (garigue) that well characterizes the Greek landscape.
Furthermore, the floristic Hellenic biodiversity is due, apart from the high fragmentation in small islands as in the Aegean Sea, also to the fact of a relatively equable climate during the succession of glacial and interglacial period, that have given rise to important micro-evolutionary systems.
In conclusion, in order to conserve the biodiversity, a strong human impact has to
be avoided, as well as a completely natural state, and each environment needs of a
specific management model to conserve the habitat of rare, endemic or endangered
species.
7. Summary – Sommario
“Biodiversità della flora greca:
contributo agli aspetti cariologici di alcune monocotiledoni”
La presente ricerca su alcune geofite della Grecia si è svolta nell'ambito del progetto Socrates nella Facoltà di Biologia di Patrasso, Grecia, nei 9 mesi dell’anno accademico 2003-2004.
Le unità studiate appartengono a varie famiglie (Alliaceae, Hyacinthaceae e Amaryllidaceae) dell’ordine Asparagales, superordine Liliiflorae, seguendo la classificazione di Dahlgren (1985) sulle Monocotiledoni.
I vari taxa sono stati esaminati nel loro aspetto citotassonomico applicando la colorazione di Feulgen ad apici radicali in attività mitotica. Questi sono stati prelevati da piante raccolte in diverse aree della Grecia e coltivate presso l’Orto Botanico sperimentale del Dipartimento di Botanica di Patrasso.
Le piante studiate provengono per la maggior parte dalle Isole Ionie (Zacinto, Cefalonia, Leucade); le altre dal Peloponneso e dalla Grecia continentale. Le varie specie in questione sono comunque spontanee nella flora greca, tranne Amaryllis belladonna che è qui presente allo stato naturalizzato.
La distribuzione di queste unità si estende generalmente a paesi mediterranei, eccetto il caso di Allium ionicum, quale endemismo greco presente esclusivamente nelle Isole Ionie.
La presente indagine ha permesso di determinare, per ogni taxon studiato, il numero cromosomico e l’idiogramma con la relativa formula idiogrammatica.
Il numero cromosomico è di seguito riportato:
Allium ionicum Brullo & Tzanoud., 2n=16 Allium paniculatum L., 2n=16
Allium guttatum Steven ssp. sardoum (Moris) Stearn, 2n=16+1B
Muscari comosum (L.) Miller, 2n=18
Muscari commutatum Guss., 2n=18 Amaryllis belladonna L., 2n=22
I numeri cromosomici di base e i complementi cariotipici ottenuti hanno confermato i dati di altri autori per l’area mediterranea. Tuttavia, analizzando in dettaglio il cariotipo ottenuto, sono state riscontrate lievi differenze, per qualcuno dei taxa studiati, rispetto ad altri autori.
Ad esempio, la posizione delle costrizioni nucleolari secondarie in Allium ionicum è risultata variabile sia tra le due popolazioni qui investigate che rispetto a popolazioni riportate da altre fonti. Comunque, queste differenze rientrano nella variabilità cariotipica e spesso possono essere interpretate come una risposta a particolari esigenze ecologiche.
I cariotipi trovati per Allium paniculatum e Allium guttatum hanno apportato un contributo ai modelli distributivi di natura citogeografica del genere Allium in Grecia, che permettono di delineare possibili percorsi migratori delle specie in questione.
Il complemento cariotipico di Muscari comosum ha confermato la ben nota eterozigosi strutturale presente nella seconda coppia cromosomica, precisando il tipo di questo polimorfismo, anch’esso di probabile valore adattativo.
Di Muscari commutatum si è accertato l’assetto cariotipico generale riscontrato da altri autori, anche in relazione alla posizione delle costrizioni secondarie e quindi dei satelliti.
Infine, lo studio cromosomico di Amaryllis belladonna ha suggerito
considerazioni cariologiche riguardo ai vari livelli di ploidia tra piante coltivate e
piante spontanee o naturalizzate.
8. Acknowledgements
I would like to gratefully acknowledge Prof. Georgia Kamari and Dr. Pepy Bareka for their enthusiastic supervision and technical support on the laboratory investigation, as well as for their hospitality and kindness.
I’m grateful also to all the other teachers and researchers of the Institute of Botany of Patras for their gentleness, in particular to Prof. Dimitris Tzanoudakis for his help in identification of the plants and Panagiotis Lambropoulos for the pleasant discussions.
I would like to express my special thank to Prof. Fabio Garbari, as careful and stimulant supervisor and, above all, for passing me his strong passion for botany during his interesting and pleasant teaching.
Thanks are due also to the rest of the staff of the Botanical Department of Pisa, in particular to Antonio Giordani, for his patient technical help.
Prof. Canio G. Vosa is warmly thanked for the numerous stimulating discussions.
Also Dr. Maria Ansaldi is gratefully thanked.
I wish to thank also my parents, for their moral help and support in each of my choises, and my sister Erica, for her precious advices and artistic touch.
A sincere thank is due my friend Alessandra della Maggiore, for the revision of this thesis, and mostly for her continuous understanding and emotional support.
I’m grateful to all my other dear friends, in particular Elena, Lorenzo, Tiziana and Aurora, and the friends of Argentinian tango, as well as the Italian and foreign friends met in Greece.
Ευχαριστίες
θα ήθελα να ευχαριστήσω τους Έλληνες καθηγητές του Πανεπιστηµίου της Πάτρας για τη βοήθεια και την υποστήριξη που µου προσέφεραν κατά τη διάρκεια της εκεί παραµονής µου.
Ringraziamenti
Vorrei esprimere un ringraziamento speciale al professor Fabio Garbari, come attento e stimolante relatore e, soprattutto, per avermi trasmesso la sua forte passione per la botanica durante i suoi interessanti e piacevoli insegnamenti.
I miei ringraziamenti sono dovuti anche al resto del personale del Dipartimento di Botanica di Pisa, in particolare ad Antonio Giordani, per il suo paziente aiuto tecnico.
Il professor Canio G. Vosa è calorosamente ringraziato per le numerose stimolanti
discussioni. Ringrazio anche la dott.sa Maria Ansaldi.
Desidero ringraziare i miei genitori, per il loro aiuto morale e supporto in ogni mia scelta, e mia sorella Erica, per i sui preziosi consigli e per il suo tocco artistico.
Un sincero grazie alla mia amica Alessandra della Maggiore, per la revisione di questa tesi, e soprattutto per la sua continua comprensione e supporto emotivo.
Ringrazio anche tutti gli altri cari amici, in particolare Elena, Lorenzo, Tiziana e Aurora, e i compagni di tango argentino, oltre a tutti gli amici italiani e stranieri incontrati in Grecia.
Field of Muscari sp. in the ancient Epidavros; nature and antiquity of Greece.