Systematik, Biodiversität und Evolution der Pflanzen




Sommersemester 2021

14.04.21: Dr. Tiina Sarkinen. Royal Botanic Garden Edinburgh, UK.

Titel: Solanaceae Systematics: Permanent Polytomies & Evolution of Epiphytes

Talk in collaboration with Edeline Gagnon, Rebecca Hilgenhof, Andres Orejuela, and Sandra Knapp.



Tackling the taxonomy and phylogeny of big genera remains one of the big challenges in plant systematics. I will present recent work on the large genus Solanum with ~1,235 currently accepted species. Providing “maps” of morphology, taxonomy, and phylogenetics has been my own research priority in Solanum to orientate experts and non-experts alike. Part of this work has been the publication of a global online multi-access key to Solanum which helps to identify species to informal groups. Phylogenomic work shows that these major and minor groups can now be considered stable based on congruent signal across both nuclear and plastome datasets. Relationships between the major clades show incongruence in many places, however, reflecting likely underlying biological processes with discordance found both within and between plastome and nuclear data. The discordant areas should perhaps best be considered as permanent polytomies to better reflect their evolutionary past, rather than holding onto a dream of perfect bifurcation. I contrast Solanum work with recent studies of epiphytic Solanaceae (tribe Solandreae), where field studies have discovered two new genera, 20 species, and fascinating natural history hidden up in the canopies.

Dr. Tiina Sarkinen Forschung: 

Host: Prof. Dr. Gudrun Kadereit


21.04.21: Dr. Kristine Westergaard. Norsk Institutt for Naturforskning, Norway.

Titel: Arctic-alpine plant phylogeography, and how we found population genomic evidence for plant glacial survival in Scandinavia


A strong barrier to plant dispersal in the circumpolar region is the North Atlantic Ocean. It has been debated for 150 years whether plants have been able to cross this ocean via long distance dispersal after the last glaciation, or whether they depended on surviving the glaciations in local ice-free refugia in different regions. This old, but still very relevant discussion, has received increasing attention in the age of DNA-analyses. I will talk about my own research on some of the most disjunctly distributed arctic-alpine plant species, how we have revealed frequent long-distance dispersal and colonisation in the North Atlantic region, and how we found population genomic evidence for plant glacial survival in Scandinavia.

Dr. Kristine Westergaard Forschung:

Host: Prof. Dr. Silke Werth


28.04.21: Jan Janouškovec. Institute of Microbiology, Czech Academy of Sciences, Czech Republic.

Titel: Genomics on protistan parasites and plankton: from cultures to single cells



In this talk, I will summarize my experience with next-generation sequencing on microbial eukaryotes. I will first discuss issues with preparing high-quality samples and processing sequence reads. Next, I will show how high-throughput sequences help us understand protist phylogeny, metabolism and trait evolution on examples of apicomplexan parasites and dinoflagellate plankton. A special attention will be paid to the challenges an benefits of sequencing yet uncultivated species from transient cultures and hand-isolated cells.

Jan Janouškovec Forschung:

Host: Prof. Dr. Marc Gottschling


05.05.21: Jarkko Salojarvi. Nanyang Technological University, Singapore.

Titel: Reading population histories from genomics data


The rapid development of high throughput sequencing platforms has brought about the golden age of population genomics, making it possible to infer population histories, relatedness and signatures of selection from population-level sequencing data. In this talk, I will present our recent results on lychee (Litchi chinensis) cultivation history as an example and then discuss how the approaches can be used to understand the ecosystem in a South East Asian rainforest.

Jarkko Salojarvi Forschung:

Host: Prof. Dr. Dierk Wanke


12.05.21: Prof. Dr. Debashish Bhattacharya. Department of Biochemistry and Microbiology, Rutgers University, U.S.A.

Titel: The rare emergence of a photosynthetic organelle



Endosymbiosis, when stable and beneficial for the “host” cell, can result in massive genetic innovation with the foremost examples being the mitochondrion and plastids. I will present results of our analysis of the rhizarian amoeba Paulinella that comprises an independent case of primary plastid endosymbiosis that occurred ca. 120 Mya. Genomic and physiological data will be used to highlight the many innovations that are needed to maintain a permanent photosynthetic endosymbiont.

Prof. Dr. Debashish Bhattacharya Forschung:

 Host: PD Dr. Andreas Beck


19.05.21: Dr. Agostina Sassone. Leibniz Institute of Plant Genetics and Crop Plant Research, Germany.

Titel: Tackling the taxonomy of Nothoscordum (Amaryllidaceae, Allioideae)

nothoscordum1 Abstract

Nothoscordum Kunth is a plant genus closely related to onions and garlic but occurs, in contrast to them, nearly exclusively in South America. It is currently not clear how Nothoscordum species are related to each other, how and where they evolved and are distributed today, and not even how many species belong to this genus. The main aim of my research is to generate an integrative approach considering morphological, karyological and molecular characters to answer these questions.

Dr. Agostina Sassone Forschung:

Host: Dr. Simon Pfanzelt


26.05.21: Doppel-Seminar (je 30 Minuten). 

Dr. Christian Siadjeu. Ludwig-Maximilians-Universität München, Germany.

Titel: Molecular breeding bases of trifoliate yam (Dioscorea dumetorum (Kunth) Pax) against post-harvest hardening phenomenon of tubers


Yams (Dioscorea spp.) are important and economical food for millions of people in the tropics and subtropics. Dioscorea dumetorum has the highest nutritional value compared to the other cultivated yam species with important medicinal properties. Despite these advantages, its cultivation is jeopardized by the post-harvest hardening (PHH) phenomenon characterized by the inability of tubers to soften during cooking. The PHH begins within 24 h after harvest and causes tubers to become inedible. Although several techniques have been deployed to solve this issue, they failed to overcome the PHH. The main objective of this thesis was to provide the basis of genetic breeding for avoidance of the PHH in D. dumetorum.

Dr. Christian Siadjeu Forschung:

Host: Prof. Dr. Gudrun Kadereit


Dr. Anže Žerdoner Čalasan. Ludwig-Maximilians-Universität München, Germany.

Titel: Genes documenting history: Biogeographical dynamics of selected Brassicaceae taxa and climate-landscape history of the Eurasian steppe belt


The Eurasian steppe belt is the vastest grassland region worldwide that has been under immense influence of the Neogene climate events. Despite its size, however, the onset and evolution of its flora is poorly understood. By employing a plethora of different phylogenetic, phylogeographic and biogeographic methods, I placed the evolutionary history of four Eurasian steppe floral elements into time and space. Interestingly, while nowadays considered an integral part of steppe flora, most of the investigated taxa migrated into the Eurasian steppe belt long after it was already developed. Several migration routes of different ages as well as different Pleistocene refugia point towards a very complex evolutionary history of the steppe flora, a glimpse of which I will give you in my talk.

Dr. Anže Žerdoner Čalasan Forschung: 

Host: Prof. Dr. Gudrun Kadereit 


02.06.21: Dr. Toby Spribille. University of Alberta, Canada.

Titel: The evolution of reciprocity in fungal-algal mutualisms: what do we know?


Apparently stable mutualistic relationships between fungi and unicellular phototrophs, usually microalgae, are common all over the Earth, and have arisen multiple times in evolution. The outcomes of many of these relationships are often similar to simple biofilms, but many develop complex, fractal three-dimensional structures. In turn, many of these three-dimensional symbiotic structures — lichens — vary across a range of phenotypes and transmit advantages to future generations of symbioses via both horizontal and vertical transmission. What is the quid pro quo that stabilizes the fungal-phototroph market, and how are symbiotic phenotypes evolved and passed on? I will review what we can glean from past work on symbiosis and symbiont physiology to ask targeted questions using modern -omics-based approaches.

Dr. Toby Spribille Forschung:

Host: Prof. Dr. Silke Werth


09.06.21: Dr. Barbara M. Thiers. The New York Botanical Garden, U.S.A.

Titel: Herbaria: Collectively Saving Plant and Fungal Biodiversity


For the past almost six centuries, scientists have been documenting the plants and fungi of the world through herbaria. The basic preparation of the specimens that are housed in an herbarium has changed relatively little over time. But the invention of this simple technology was a key innovation in transforming the study of these organisms from a minor subdiscipline of medicine into an independent scientific endeavor. The herbarium has made it possible for scientists to characterize the plants and fungi that grow in faraway places and to understand their diversity on a global scale. The men and women collectors and curators responsible for the wealth of herbaria we have today (about 3400 herbaria holding an estimated 400 million specimens), are diverse in national heritage, education and social status. The geographic, taxonomic, and temporal breadth of their legacy allows us to understand the diversity of the world’s vegetation in the past and present, and to predict its future. Herbaria still serve their original function – to document the occurrence of plants and fungi and provide a reference for their identification and characterization. However, recent technological advances that facilitate the study of life at both the molecular level and on a global scale can be applied to herbarium specimens to help address some of the most critical problems we face today. New ways of sharing information allow herbaria demonstrate the importance of plants and healthy ecosystems to an audience far beyond the scientific community.

Dr. Barbara M. Thiers Forschung:

Host: Dr. Hans-Joachim Esser


16.06.21: Dr. Ricarda Riina. Real Jardín Botánico de Madrid. CSIC, Spain.

Titel: Plant diversity and phylogenetic patterns across the tepuis of the Guiana Shield


The talk will give an overview of the vascular flora of the tepuis or table-top mountains of the Guayana Shield. These mountains, collectively known as Pantepui, are recognized as an important center of plant diversity and endemism in the Neotropics. Emphasis of the presentation will be on the main diversity and biogeographic patterns across tepuis. Phylogenetic and biogeographic studies are starting to shed some light on the origin, age, and evolutionary history of this highly specialized flora.

Dr. Ricarda Riina Forschung:

Host: Dr. Andreas Gröger


23.06.21: Dr. Julius Jeiter. Nees-institute for Biodiversity of Plants, University of Bonn, Germany.

Titel: Flower and fruit evolution in Boraginales

leiter Abstract

In my talk, I am going to give an overview of my research on flower and fruit evolution in Boraginales. Boraginales comprise about 2700 species in 125 genera. Their flower and fruit morphology is strikingly diverse, given the fact that most species have a similar flower organisation (Bauplan). Two aspects are in the focus of my research: mechanisms involved in the independent transitions from capsules to nutlets and the evolution of various modifications of the stamen-corolla tube and their integration into the flower as a functional unit. I study these aspects using standard (light and scanning electron microscopy) and 3D-visualisation methods (µCT), which gives insights into complex 3D-structures and produces stunning visualisations. Part of my talk, I would like to dedicate to the brief discussion of the role of “classical” morphology in a modern research landscape.

Dr. Julius Jeiter Forschung: 

Host: Prof. Dr. Marc Gottschling


30.06.21: Prof. Dr. Norbert Jürgens. Department for Biodiversity, Evolution and Ecology, University of Hamburg, Germany.

Titel: Interaction among social insects and plants shapes ecosystems and landscapes in African drylands and wetlands


This talk offers an update on one of the ten most astonishing ecological debates of the past decade (if we follow CNN). A large proportion of African landscapes is not formed by one vegetation type but the vegetation is extremely different (a) within regularly occurring circular structures and (b) in the surrounding matrix vegetation. The circular structures in some cases have the size of a house while others are just a few decimetre wide. Examples are presented from hyperarid deserts with less than 50 mm MAP but also from seasonally inundated moist Miombo woodlands. While some authors propose that competitive feedback mechanisms among plants alone generate such fairy circle patterns, the talk will present phylogenetic, biological and ecological evidence which supports a causative role of social insects, mainly termites.

Prof. Dr. Norbert Jürgens Forschung:

Host: Prof. Dr. Dierk Wanke


07.07.21: Dr. Madeleine Seale. Department of Plant Sciences, University of Oxford, UK.

Titel: Form and function of the dandelion fruit


The familiar fruit of the dandelion is dispersed by wind, sometimes for many kilometres. This is enabled by it’s carefully constructed pappus – a set of hairs that forms a parachute-like structure. Though constructed of dead cells, the pappus is not a completely passive player during dispersal as it is able to modify its shape in response to moisture. In this talk, I will use the example of the dandelion fruit to consider how biomechanics, fluid dynamics and ecology can be combined to understand plant form and function.

Dr. Madeleine Seale Forschung:

Host: Prof. Dr. Gudrun Kadereit


14.07.21: Prof. Dr. Susanne Renner. Washington University, Department of Biology, Saint Louis (Missouri), U.S.A.

Titel: Why botanists should follow zoologists in permitting nuclear DNA sequences (or assembled genomes) as de facto nomenclatural types


The type method was proposed in 1843, but botanists and mycologists only fully accepted it in 1935. This method solves the problem of how one might attach language (specifically, 2 words) to biological entities, which for practical and theoretical reasons are never completely known. It does this by permanently attaching a name to a specimen or illustration that serves as a name-bearer (nomenclatural type). In all three main codes (fungi, animals, plants), descriptions are a VOLUNTARY alternative to diagnoses (which are called definitions in the zoo. Code). Moreover, the traits seen in the type overwrite any word in the protologue, regardless of the effort put into the diagnosis or description. Given the relative unimportance of words in the protologue, but essentialness of types (for all time), there are now discussions in all taxonomic communities to permit genomic data as nomenclatural types, with zoologists and researchers of uncultivated prokaryotes the furthest along in their thinking. Thus, the commission on zoological nomenclature voted on 2 Nov. 2016 to permit sequences to serve as de facto types (search ‘Declaration 45’ for details). In this talk, I will discuss why botanists and mycologists might consider one of the approaches taken by zoologists and prokaryote researchers. In short, a nomenclatural type has to fulfil three criteria: (1) It has to be storable for a long time, ideally cheaply & forever; (2) it has to be easily retrievable, ideally from a database; and (3) it has to be uniquely identifiable via a Digital Identifier. For future research, especially on insects, soil and aquatic organisms, and endangered plants and animals, genomic data might often be as useful as illustrations, which are currently permitted as nomenclatural types, even in the new (2019) mycological code.

Prof. Dr. Susanne Renner Forschung:

Host: Prof. Dr. Gudrun Kadereit