Cytogenetic insights into plant diversification: Asteraceae as a case study J. Pellicer, O. Hidalgo, D. Vitales, J. Vallès, A. Santos- Guerra, A. García, S. Siljak-Yakovlev Talk outline: • The genus Cheirolophus Cass. • Phylogenetics and diversification patterns across the Mediterranean basin and Macaronesia • Evolution of cytogenetic traits in Cheirolophus: • Chromosome data • Genome size • Ribosomal DNA loci Why Cheirolophus ? Vitales et al. 2014, 14: 118 Vitales et al. 2015, 85-100 PHYLOGENETICS Garnatje et al. 2007, 264: 117-134 Vitales et al. 2014, 9: e113207 PHYLOGEOGRAPHY Cheirolophus Cass. Vitales et al. 2015, in press. Vitales et al. 2014, 14: 118 Vitales et al. 2015, 85-100 Vitales et al. 2013, 32: 21-31 PHYLOGENETICS REPRODUCTION Garnatje et al. 2007, 264: 117-134 BIOLOGY Vitales et al. 2014, 9: e113207 PHYLOGEOGRAPHY Cheirolophus Cass. Vitales et al. 2015, in press. Garnatje et al. 1998, 213: 57-70 POPULATION GENETICS Vitales et al. 2015, 179: 157-171 Vitales et al. 2014, 14: 118 Vitales et al. 2015, 85-100 Vitales et al. 2013, 32: 21-31 PHYLOGENETICS REPRODUCTION Garnatje et al. 2007, 264: 117-134 BIOLOGY Vitales et al. 2014, 9: e113207 Garnatje et al. 2007, 264: PHYLOGEOGRAPHY Cheirolophus Cass. 117-134 Vitales et al. 2015, in press. Hidalgo et al. submitted CYTOGENETICS Garnatje et al. 1998, 213: 57-70 Garnatje et al. 2012, 55: POPULATION 529-235 GENETICS KARYOLOGY Vitales et al. 2015, 179: 157-171 Hidalgo et al. submitted Vitales et al. 2014, 14: 118 Vitales et al. 2015, 85-100 PHYLOGENETICS Garnatje et al. 2007, 264: 117-134 Vitales et al. 2014, 9: e113207 PHYLOGEOGRAPHY Cheirolophus Cass. Vitales et al. 2015, in press. Vitales et al. 2014, 14: 118 Vitales et al. 2015, 85-100 PHYLOGENETICS Garnatje et al. 2007, 264: 117-134 Vitales et al. 2014, 9: e113207 Garnatje et al. 2007, 264: PHYLOGEOGRAPHY Cheirolophus Cass. 117-134 Hidalgo et al. submitted Vitales et al. 2015, in press. CYTOGENETICS Garnatje et al. 2012, 55: 529-235 Cheirolophus Cass.: c. 28 spp Cheirolophus Cass.: c. 28 spp Cheirolophus Cass.: c. 28 spp Cheirolophus crassifolius Cheirolophus Cass.: c. 28 spp Cheirolophus intybaceus Cheirolophus crassifolius Cheirolophus Cass.: c. 28 spp Cheirolophus uliginosus Cheirolophus intybaceus Cheirolophus sempervirens Cheirolophus crassifolius Cheirolophus Cass.: c. 28 spp Cheirolophus uliginosus Cheirolophus intybaceus Cheirolophus sempervirens Cheirolophus crassifolius Cheirolophus tananicus, Ch. benoistii and Ch. mauritanicus Cheirolophus Cass.: c. 28 spp Cheirolophus Cass.: c. 28 spp Cheirolophus burchardii Cheirolophus satarataensis Cheirolophus falcisectus Cheirolophus Cass.: Phylogenetics and diversification Phylogenetics and diversification of Cheirolophus • ITS and ETS provides resolution at the backbone of the tree. • Monophyly of the genus and early- diverged position of Ch. crassifolius from Malta. • Early-branching of the Iberian hemicryptophyte Ch. uliginosus, but not entirely resolved. • Well defined Mediterranean clade, reflecting morphologic and geographic affinities among the species. • Macaronesian clade poorly resolved. Vitales et al. 2014, 14: 118 Phylogenetics and diversification of Cheirolophus • ITS and ETS provides resolution at the backbone of the tree. • Monophyly of the genus and early- diverged position of Ch. crassifolius from Malta. • Early-branching of the Iberian hemicryptophyte Ch. uliginosus, but not entirely resolved. • Well defined Mediterranean clade, reflecting morphologic and geographic affinities among the species. • Macaronesian clade poorly resolved. • Plastid DNA shows less variability and resolution at the backbone of the tree. • More variability and better resolution within the Canarian lineage than ITS- ETS. Vitales et al. 2014, 14: 118 Phylogenetics and diversification of Cheirolophus i) Origin of the genus: mid- late Miocene 10.37 Ma 24.51 Ma; Barres et al. 2013. Vitales et al. 2014, 14: 118 Phylogenetics and diversification of Cheirolophus i) Origin of the genus: mid- late Miocene ii) Gap in diversification during 5 My. 10.37 Ma 24.51 Ma; Barres et al. 2013. Vitales et al. 2014, 14: 118 Phylogenetics and diversification of Cheirolophus i) Origin of the genus: mid- late Miocene ii) Gap in diversification during 5 My. iii) New burst of diversification after 3 Ma. (Mediterranean) 10.37 Ma 3.08 Ma 24.51 Ma; Barres et al. 2013. Vitales et al. 2014, 14: 118 Phylogenetics and diversification of Cheirolophus i) Origin of the genus: mid- 1.74 Ma late Miocene ii) Gap in diversification during 5 My. iii) New burst of diversification after 3 Ma. (Mediterranean) 10.37 Ma 3.08 Ma iv) New burst of accelerated diversification after 1.7 Ma. (Macaronesia) 24.51 Ma; Barres et al. 2013. Vitales et al. 2014, 14: 118 Phylogenetics and diversification of Cheirolophus Multiple processes involved in radiation: – Colonisation between islands – Intra-island allopatric speciation – Incipient ecological adaptation – Hybridisation signals Vitales et al. 2014, 14: 118 Phylogenetics and diversification of Cheirolophus • Mul%ple colonizaons intra- and inter-islands • Sporadic long distance dispersal ability Phylogenetics and diversification of Cheirolophus • Mul%ple colonizaons intra- and inter-islands • Sporadic long distance dispersal ability Ch. intybaceus; Garnatje et al. (2012) Calonectris diomedea Cheirolophus Cass.: Chromosome evolution Chromosome evolution in Cheirolophus Chromosome numbers • Chromosome counts for c. 25 spp. 2n = 30,32 Chromosome evolution in Cheirolophus Chromosome numbers • Chromosome counts for c. 25 spp. 2n = 30,32 • The chromosome number 2n = 32 is more frequent than previously reported. • The ancestral chromosome number in Cheirolophus is 2n = 32, appearing 2n = 30 several independent times in the evolutionary history of the genus. Chromosome evolution in Cheirolophus Chromosome numbers • Chromosome counts for c. 25 spp. 2n = 30,32 • The chromosome number 2n = 32 is more frequent than previously reported. • The ancestral chromosome number in Cheirolophus is 2n = 32, appearing 2n = 30 several independent times in the evolutionary history of the genus. Chromosome evolution in islands Chromosome evolution in islands Oceanic islands STASIS... Chromosome evolution in islands Oceanic islands STASIS... ENDEMICS Stuessy & Crawford 1998, 307-321 Chromosome evolution in islands Oceanic islands STASIS... ENDEMICS NON-ENDEMICS Stuessy & Crawford 1998, 307-321 Cheirolophus Cass.: Nuclear DNA contents Genome size evolution in Cheirolophus 2C-values: 1.30-1.80 pg • New data confirm that of Garnatje et al. (2007), where significant differences in GS among Mediterranean and Macaronesian species were observed • Ch. crassifolius shows the highest value of DNA amount, indicating a progressive decline of GS since the origin of the diversification of the genus. Genome size evolution in Cheirolophus 2C-values: 1.30-1.80 pg • New data confirm that of Garnatje et al. (2007), where significant differences in GS among Mediterranean and Macaronesian species were observed • Ch. crassifolius shows the highest value of DNA amount, indicating a progressive decline of GS since the origin of the diversification of the genus. • The descending pattern would be particularly strong in the oceanic islands, consistent with the results found in other plant groups. Genome size evolution in Cheirolophus 2C-values: 1.30-1.80 pg • New data confirm that of Garnatje et al. (2007), where significant differences in GS among Mediterranean and Macaronesian species were observed MRCA: • Ch. crassifolius shows the highest value of DNA amount, 1.59-1.65 pg/ indicating a progressive decline of GS since the origin of the 2C diversification of the genus. • The descending pattern would be particularly strong in the oceanic islands, consistent with the results found in other plant groups. Genome size evolution: island colonisations Artemisia Hawaii Hobbs & Baldwin 2013, 40: 442-454 ) pg Genome size 1Cx ( Continental Hawaii Macaronesia Pellicer et al. (unpublished) Genome size evolution: island colonisations Artemisia Hawaii Macaronesia Hobbs & Baldwin 2013, 40: 442-454 ) pg Genome size 1Cx ( Continental Hawaii Macaronesia Pellicer et al. (unpublished) Genome size evolution: island colonisations Hawaiian Schiedea ...“Unexpectedly, genomes of Schiedea species appeared to be relatively compact (1.41 to 3.74 pg/ cell), compared to Honckenya (8.57 to 10.66 pg/ cell)”... GS (Kapralov & Filatov, 2009, 2:77-83) Genome size evolution: island colonisations Hawaiian Schiedea ...“Unexpectedly, genomes of Schiedea species appeared to be relatively compact (1.41 to 3.74 pg/ cell), compared to Honckenya (8.57 to 10.66 pg/ cell)”... GS (Kapralov & Filatov, 2009, 2:77-83) Genome size evolution: island colonisations Hawaiian Schiedea ...“Unexpectedly, genomes of Schiedea species appeared to be relatively compact (1.41 to 3.74 pg/ cell), compared to Honckenya (8.57 to 10.66 pg/ cell)”... YES, but... GS (Kapralov & Filatov, 2009, 2:77-83) Genome size evolution: island colonisations • Radiation processes only takes place involving species with smaller genome sizes Genome size evolution: island colonisations • Radiation processes only takes place involving species with smaller genome sizes • Genome downsizing has a direct impact in facilitating/enhancing the radiation process Genome size evolution: island colonisations • Radiation processes only takes place involving species with smaller genome sizes • Genome downsizing has a direct impact in facilitating/enhancing the radiation process • Genome downsizing is just a consequence of the radiation,