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Kissling, Jonathan

Nom
Kissling, Jonathan
Affiliation principale
Fonction
Chargé de cours
Email
jonathan.kissling@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/334
_
0000-0002-1078-4000

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  • Publication
    Accès libre
    Evolutionary diversification in the hyper-diverse montane forests of the tropical Andes: radiation of Macrocarpaea (Gentianaceae) and the possible role of range expansion
    (2021-11-19)
    Kissling, Jonathan 
    ;
    Vieu, Julien 
    ;
    Hughes, Colin
    ;
    Grant, Jason 
    The humid mid-elevation montane forests (MMF) of the tropical Andes harbour high levels of plant species diversity, contributing to the exceptional overall diversity of the tropical Andean biodiversity hotspot. However, little is known about the diversification dynamics of MMF plant lineages compared to lineages in other Andean biomes. Here, we use Macrocarpaea (Gentianaceae) to investigate patterns of plant diversification in the MMF, using molecular dating with fossils and secondary calibration (from a family-wide phylogenetic analysis of Gentianaceae). We sequenced 76 of 118 recognized Macrocarpaea spp. for six markers to reconstruct a time-calibrated phylogenetic tree and infer the historical biogeography of Macrocarpaea using maximum-likelihood methods implemented in BioGeoBEARS, estimating diversification rates through time and among lineages with BAMM. We document a rapid radiation of Macrocarpaea in Andean MMF coinciding with rapid colonization and range expansion across the entire distribution of the genus in the Andes starting 7.2 Mya. Our results support allopatric founder-event speciation as the dominant process contributing to geographical phylogenetic structure across the genus. We propose that establishment of the MMF in the late Miocene, when the Andes attained critical elevation to modify regional climates, provided large new areas of suitable habitat for Macrocarpaea to quickly colonize and expand through repeated founder-events. We suggest that this wave of colonization and range expansion triggered rapid diversification, and, as the MMF became progressively occupied, the diversification rate slowed. Our study also supports the idea that MMF plant radiations are older and more slowly evolving than the quickly evolving lineages in the recent Andean high-elevation grasslands.
  • Publication
    Accès libre
    Ancestral and monophyletic presence of diplostigmaty in Sebaea (Gentianaceae) and its potential role as a morphological mixed mating strategy
    (2009)
    Kissling, Jonathan 
    ;
    Endress, Peter K.
    ;
    Bernasconi, Giorgina
    • Diplostigmaty, the presence of a primary (apical) stigma and secondary (mid-stylar) stigmas along the style, is only known from the genus Sebaea (Gentianaceae). Early work indicated that the secondary stigmas provide a mechanism of autogamy, suggesting that it might ensure reproductive assurance.
    • Here, we test the monophyly of this unique morphological trait. Using Bayesian methods, we infer a nuclear DNA phylogeny for 96 accessions, including c. 50% of the species from the genus Sebaea. With this phylogeny, we infer the distribution of ancestral states on critical nodes using parsimony and likelihood methods.
    • The inferred nrDNA phylogeny shows that the genus Sebaea is divided in two statistically well-supported clades, A and B, consistent with recent estimates. The most recent ancestor (MRCA) of clade A, except the most basal species (Sebaea pusilla), is resolved as diplostigmatic. No reversal to a single stigma is observed within this clade.
    • We suggest that diplostigmaty is evolutionarily stable through time. We also discuss why this reproductive system is not found elsewhere than in Gentianaceae and the potential advantage of diplostigmaty as a stable mixed mating strategy.
  • Publication
    Accès libre
    Phylogenetics of tribe Exaceae (Gentianaceae) based on molecular, morphological and karyological data, with special emphasis on the genus Sebaea.: Taxonomic treatment of Exochaenium, Lagenias and the new genus Klackenbergia
    (2007)
    Kissling, Jonathan 
    ;
    Küpfer, Philippe 
    ;
    Linder, Peter
    In an attempt to understand the evolutionary history of the poorly studied genus Sebaea and its relationship to other genera of tribe Exaceae (Gentianaceae), intensive morphological and karyological character optimization based on robust molecular phylogeny was performed. Phylogenetic reconstructions support the monophyly of Exaceae, and further reveal a polyphyletic Sebaea, including four well-supported clades, hereafter treated as separate genera, based on non-molecular synapomorphies. The first clade contains the single species Lagenias pusillus, characterized by its medifix anthers, inserted at the base of the corolla tube and its seed testa cells (polygonal). The second clade, Sebaea s. str., contains most of the South African species having secondary stigmas and bilateral seeds, with rectangular testa cell. The third clade, Exochaenium, contains exclusively tropical African species, characterized by a stylar polymorphism and a papillose clavate stigma (versus smooth and bilobed). Finally the fourth clade, Klackenbergia, contains two species characterized by inflorescences with axillary subsessile flowers. Based on these results, the taxonomic reinstatement of Exochaenium (23 species) and Lagenias (1 species), along with the establishment of a new genus Klackenbergia (2 species), are proposed. In the light of the new phylogenetic relationships found within the Exaceae, new views on the evolution of (1) karyological and (2) morphological characters are proposed. Finally, the historical biogeography of the tribe is reevaluated (3). 1. Intensive chromosome counts based on material collected and fixed in the field (157 population and c. 60 species), and exhaustive literature survey, reveal a broad set of chromosome numbers (2n = 18, 28, 32, 34, 36, 42, 52, 54, 56, 60, 62, 64, 68), and the occurrence of polyploid systems within Exacum and Sebaea. These results allow us to postulate x = 7, 8, or 9 as the possible base chromosome numbers for the Exaceae. Karyological reconstruction, based on the molecular phylogeny, suggest a basic number of x=7 for the Exaceae, followed by dysploidy event leading to secondary base number of x=8 and x=9, and several polyploidization events. 2. Optimization of morphological characters suggests that the most recent common ancestor of Exaceae (MRCA) was similar to Lagenias pusillus by having pentamerous yellow actinomorphic flowers, with anthers included in the corolla tube and dehiscing by longitudinal slits, a bilobed stigma, and the absence of secondary stigmas, and cubical seeds with polygonal testa cells. This MRCA might have then developed particular floral syndromes as indicated by long corolla tubes or presence of enantiostyly in the tribe. 3. Dating analyses and dispersal-vicariance reconstructions suggest that the Exaceae evolved c. 32 million years ago in Africa and subsequently spread to Madagascar. The colonization of Australia, New-Zealand, and Asia involved at least three long-distance dispersals. Early diversification of Exaceae in Africa might be the consequence of the development of a temperate with dry summer climate, in the Cape region (South Africa), while the Quaternary climatic variation might explain most of the species diversity of Sebaea and Exochaenium. At the generic level, molecular phylogenies of Sebaea, based on chloroplastic and nuclear DNA markers, reveals five well-supported clades. Sebaea sulphurea seems to have evolved early, and is distinct from all the remaining extant species. Each clade is supported by several characters (morphological, vegetative, phenological or geographical), and a preliminary infrageneric classification is proposed.