Universite de Montreal Origin of Symphyotrichum anticostense (Asteraceae: Astereae), an endemic species of the Gulf of St. Lawrence par Jamil Vaezi Departement de Sciences biologiques Universite de Montreal These presentee a la Faculte des etudes superieures en vue de l'obtention du grade de Ph.D. en Sciences biologiques Juillet 2008 Wart* © Jamil Vaezi, 2008 «e :& v m, *&B***y» 09, Library and Archives Bibliotheque et 1*1 Canada Archives Canada Published Heritage Direction du Branch Patrimoine de I'edition 395 Wellington Street 395, rue Wellington Ottawa ON K1A 0N4 OttawaONK1A0N4 Canada Canada Your file Votre reference ISBN: 978-0-494-53553-0 Our file Notre reference ISBN: 978-0-494-53553-0 NOTICE: AVIS: The author has granted a non­ L'auteur a accorde une licence non exclusive exclusive license allowing Library and permettant a la Bibliotheque et Archives Archives Canada to reproduce, Canada de reproduire, publier, archiver, publish, archive, preserve, conserve, sauvegarder, conserver, transmettre au public communicate to the public by par telecommunication ou par I'lnternet, preter, telecommunication or on the Internet, distribuer et vendre des theses partout dans le loan, distribute and sell theses monde, a des fins commerciales ou autres, sur worldwide, for commercial or non­ support microforme, papier, electronique et/ou commercial purposes, in microform, autres formats. paper, electronic and/or any other formats. The author retains copyright L'auteur conserve la propriete du droit d'auteur ownership and moral rights in this et des droits moraux qui protege cette these. Ni thesis. Neither the thesis nor la these ni des extraits substantiels de celle-ci substantial extracts from it may be ne doivent etre imprimes ou autrement printed or otherwise reproduced reproduits sans son autorisation. without the author's permission. In compliance with the Canadian Conformement a la loi canadienne sur la Privacy Act some supporting forms protection de la vie privee, quelques may have been removed from this formulaires secondaires ont ete enleves de thesis. cette these. While these forms may be included Bien que ces formulaires aient inclus dans in the document page count, their la pagination, il n'y aura aucun contenu removal does not represent any loss manquant. of content from the thesis. •+l Canada Universite de Montreal Faculte des etudes superieures Cette these intitulee: Origin of Symphyotrichum anticostense (Asteraceae: Astereae), an endemic species of the Gulf of St. Lawrence presentee par : Jamil Vaezi a ete evaluee par un jury compose des personnes suivantes : Anne Bruneau, Presidente rapporteuse Luc Brouillet, directeur de recherche Mohamed Hijri, membre du jury Geraldine A. Allen, examinatrice externe Representant du doyen de la FES 11 Abstract This thesis discusses the origin of Symphyotrichum anticostense, a decaploid species restricted to the Gulf of St. Lawrence region (Quebec, New Brunswick, and Maine). Two closely related species, S. novi-belgii, a hexaploid and S. boreale, a putatively tetraploid species have been proposed to be putative parents of S. anticostense. Symphyotrichum novi-belgii is distributed in the eastern coastal region of North America and S. boreale is widespread throughout the northern part of North America from west to east. These three species belong to the genus Symphyotrichum, which comprises ca. 91 species of which more than 50% are polyploids. The evolutionary history of the genus is poorly known even at the diploidy level. Before investigating the origin of S. anticostense, it seems necessary in the first step to elucidate phylogenetic relationships within the genus. The objectives of this thesis are therefore to delimit species boundaries excluding polyploid species and to investigate the origin of S. anticostense. The ITS data set nearly supports previous classifications based on morphological and cytological approaches, while the GAPDH nuclear gene is in poor agreement with the ITS results. Incomplete lineage sorting within Symphyotrichum is shown by stochastic sorting of ancestral polymorphisms among the GAPDH alleles. This evidence, in combination with the insufficient resolution among ribotypes, suggests recent evolutionary radiation of the genus. Univariate and multivariate morphological analyses as well as the ITS results roughly support S. anticostense to be a hybrid derivative of S. novi-belgii and S. boreale. The ITS-based network analysis suggests three independent geographical origins for S. anticostense: 1) Lake St. John; 2) Gaspe Peninsula- New Brunswick- Maine; 3) Anticosti Island. The results of two nuclear genes (GAPDH and MIPS) demonstrate relative incongruence between the phylogenetic trees. Although the results obtained from the in latter markers support those obtained from the morphological and ITS data sets, incomplete lineage sorting strongly affected the phylogenetic relationships among species. Key words: Asteraceae, Astereae, Symphyotrichum, Symphyotrichum anticostense, polyploidy, hybridization, phylogeny, incongruence, incomplete lineage sorting, radiation. IV Resume Cette these porte sur l'origine de Symphyotrichum anticostense, une espece decaploide de la region du golfe du Saint-Laurent (Quebec, Nouveau Brunswick, et Maine). II a ete propose que S. anticostense serait une allopolyploid derivee de l'hybride entre S. novi-belgii, une hexaploide et S. boreale, une espece putatifment tetraploi'de. S. novi-belgii est distribute dans la region cotiere d'est d'Amerique du Nord et S. boreale est repandue a travers de la partie du nord d'Amerique du Nord de l'ouest a Test. Ces trois especes appartient au genre Symphyotrichum qui comprend 91 espece. Plus que 50% de celles-ci sont polyploides. Les relations phylogenetiques au sein du genre sont aussi inconnues meme au niveau diploi'die. Avant d'examiner l'origine de S. anticostense, il semble necessaire dans la premiere etape d'expliquer les relations phylogenetiques du genre. Les objectifs de cette these sont done de delimiter des especes excluant des polyploides et examiner l'origine de S. anticostense. Le resultat d'analyse de donnee de PITS supporte presque des classifications auparavant basees sur les approches morphologiques et cytologiques. Le resultat du gene nucleaire GAPDH est faiblement en accord avec le resultat obtenu de PITS. Le triage des lignees incomplet dans Symphyotrichum est souligne par le triage au hasard des polymorphismes ancestraux parmi les alleles de GAPDH. Cette preuve ainsi que la resolution insuffisante parmi ribotypes, suggerent une evolution recente du genre. Des analyses univariees et multivariees de donnees morphologiques ainsi que le resultat de marqueur dTTS supportent la position taxonomique de S. anticostense comme un hybride derivee de S. novi-belgii et S. boreale. L'analyse basee sur reseau des ribtypes suggere trois origines geographiques pour S. anticostense: 1) Lac Saint-Jean ; 2) Gaspesie- Nouveau Brunswick- Maine ; 3) l'lle d'Anticosti. Les resultats de deux genes nucleaires (GAPDH v et MIPS) demontrent relativement l'incongruence entre les arbres phylogenetiques. Bien que les resultats obtenus de ces marqueurs supportent ceux-la obtenus des donnees morphologiques et 1'ITS, le triage des lignees incomplet a affecte extremement les relations phylogenetiques parmi des especes. Mots cles : Asteraceae, Astereae, Symphyotrichum, Symphyotrichum anticostense, polyploidie, hybridation, phylogenie, incongruence, triage des lignees incomplet, radiation. VI Table of Contents Abstract Hi Resume v Table of Contents vii List of tables x List of figures xi List of abbreviations xiii Acknowledgments xiv CHAPTER 1 Introduction 1 1.1 Taxonomic history of Symphyotrichum anticostense 4 1.2 Biological characteristics 5 1.2.1 Taxonomy 5 1.2.2 Distribution 10 1.2.3 Ecology 12 1.3 Objectives 13 1.4 Polyploidy 15 1.5 Hybridization 16 1.5.1 Detection of hybrid speciation 16 1.5.2 Reticulate evolution and multiple origins 18 1.6 Lineage sorting 20 CHAPTER 2 Phylogenetic relationships among diploid species of Symphyotrichum (Asteraceae: Astereae) based on two nuclear markers: ITS and GAPDH 22 2.1 Resume 22 2.2 Abstract 23 2.3 Introduction 24 vii 2.4 Materials and Methods 27 2.4.1 Taxon sampling 27 2.4.2 Molecular methods 30 2.4.3 Data analyses 32 2.5 Results 35 2.5.1 ITS analysis 35 2.5.2 GAPDH analysis 37 2.5.3 ILD test 37 2.5.4 Nesting the gene trees within the species tree 37 2.6 Discussion 39 CHAPTER 3 Origin of Symphyotrichum anticostense (Asteraceae: Astereae), an endemic, high polyploid species of the Gulf of St. Lawrence, based on morphological and nrDNA evidence 45 3.1 Resume 45 3.2 Abstract 46 3.3 Introduction 47 3.4 Materials and Methods 52 3.4.1 Taxon sampling 52 3.4.2 Morphological analysis 59 3.4.3 Molecular analysis 61 3.5 Results 63 3.5.1 Morphometric analyses 63 3.5.2 Molecular analyses 69 3.6 Discussion 73 3.6.1 Morphological evidence 73 3.6.2 Molecular evidence 75 3.6.3 Geographic hybrid origins 77 CHAPTER 4 Inferring parental lineages of a high allopolyploid, Symphyotrichum anticostense (Asteraceae: Astereae) using two nuclear markers 79 4.1 Resume 79 4.2 Abstract 80 via 4.3 Introduction 80 4.4 Materials and Methods 84 4.4.1 Plant materials and DNA isolation 84 4.4.2 Primer design, DNA amplification, sequencing and cloning 89 4.4.3 Phylogenetic analyses 90 4.5 Results 93 4.5.1 GAPDH analysis 93 4.5.2 MIPS analyses 95 4.6 Discussion 99 4.6.1 Origin of Symphyotrichum anticostense 99 4.6.2 Gen(om)e duplication 102 CHAPTER 5 Conclusion 103 5.1 Phylogenetic relationships within Symphyotrichinae 103 ITS or GAPDH: Which gene tree reflects best the species tree? 103 5.2 Origin of Symphyotrichum anticostense 104 5.3 Gen(om)e duplication 106 5.4 The future 109 References Ill Appendix 1 130 Appendix 2 132 ix List of tables Table 1.1 Taxonomic treatment of Symphyotrichum anticostense 4 Table 1.2 Two main classifications proposed by Nesom (1994b) and Semple (2005) for genus Symphyotrichum 9 Table 1.3 Taxonomic position of <S.