8 April: Ib Linde-Laursen

My life with Hordeum chromosomes

Ib Linde-Laursen

dept. Agriculture and Ecology, Copenhagen University

The genus Hordeum (Barley) belongs to the tribe Triticeae of the Poaceae. The tribe comprises the cereal crops wheat, barley and rye and many important forage grass species, in all about 350 species. The genus Hordeum includes 32 species and altogether 45 taxa occurring in temperate regions of the world except in Australia. Relatively most species are found in South America. The species have 14, 28 or 42 large chromosomes in somatic cells. The chromosomes, excepting those wearing ‘satellites’ are morphologically so similar within chromosome complements (karyotypes) that they can only be identified reliably using special procedures producing patterns of cross-bands in the chromosomes. In the inbreeding Hordeum vulgare (cultivated barley) use of Giemsa C-banding demonstrates 7 different banding patterns, each pattern occurring in two of barley’s 14 chromosomes, i.e. in one of the 7 pairs. The bands may vary in size and position although not to a degree which renders it impossible to recognize the basic banded karyotype of H. vulgare in barley lines (varieties). Banding patterns may establish the parental origin of their chromosomes. Bands show Mendelian segregation and can be used to assign genes to chromosome regions. Each of the 45 Hordeum taxa has its specific basic banded karyotype, but this may not be so dissimilar relative to those of other taxa that it is possible to distinguish taxa on this basis. Interspecific hybrids among H. vulgare and Hordeum taxa with 28 or 42 chromosomes may show partial or complete elimination of 7 chromosomes, generally those of H. vulgare corresponding to one genome. Based on chromosome elimination patterns a hypothesis is put forward that the chromosomes have an orderly arrangement within the genome. In hybrids with the related Psathyrostachys fragilis (14 chromosomes) and in the interspecific Hordeum hybrids, the H. vulgare chromosomes are on an average lying closer to the cell centre than the chromosomes of the other parent supporting that the two genomes occupy different compartments.

25 March: Christoph Scherber

Effects of plant species richness on plant-herbivore and multitrophic interactions

Christoph Scherber

dept. Crop Sciences, Agroecology, Georg-August-University Göttingen, Germany

Biodiversity is rapidly declining, yet we still don't know if this decline leads to consistent changes in ecosystems. While the past decades have seen enormous efforts to study the effects of biodiversity loss on ecosystem processes, many studies still focused on plant productivity and related variables. Thus, the response of many components of terrestrial ecosystems to biodiversity loss have remained largely unexplored.

In this talk, I will take a systems perspective on plant biodiversity and show how different groups of organisms respond to changes in plant species richness. From soil microbes to aboveground pollinators, show that losses of plant diversity cascade up and down in food webs. Biodiversity loss is negative for many groups and processes, but there are exceptions.

In conclusion, the studies I present in the talk show that plants indeed form the basis for aboveground and belowground food webs, and that losses in plant diversity ultimately lead to indirect co-extinctions in many different groups of organisms.

11 March: Bjarne Larsen

Crocus – Evolution and Domestication

Bjarne Larsen

dept. Agriculture and Ecology, Copenhagen University

The genus Crocus contains about 80 species of corm-bearing perennial geophytes. Crocus grows generally in mountainous areas from sea level up to 2500 m, mostly on limestone ground in winter rain areas around the Mediterranean Sea. The largest diversity of species is found in Turkey, but species are found all the way from Portugal /Spain in west to Western China in east. Characteristic for most species is a limited geographical distribution where species have adapted to specific habitats. The flowering season of Crocus is almost throughout the year depending on species. The diversity of a number of the spring-flowering species is used for ornamental purposes. Hybrids between C. biflorus and C. chrysanthus have arisen during the last hundred years, resulting in a wide range of flower colors and shapes, which has gained popularity as early spring garden plants.

One of the most valuable crocuses, is the saffron crocus, Crocus sativus. This autumn-flowering species are grown for the world’s most expensive spice, saffron. C. sativus has been cultivated 4000 years back in time but is not known to occur in the wild. The ancestors of this triploid (2n=24), sterile species is not known, but C. cartwrightianus, a closely related diploid (2n=16) species from the Attica peninsula of Greece is believed to have taken part in ancient hybridization events resulting in C. sativus. This unique hybridization event has since then given corms to all the world’s saffron crocuses by vegetative reproduction.

The enormous diversity of Crocus represents a history of massive hybridization and specialization. Inter- and intraspecific variation suggests that the genus during evolution has been exposed to huge adaption demands and selection pressure.

25 February: Dag Terje Filip Endresen

Notice: the seminar will be in the lecture room in the greenhouse basement , Rolighedsvej 21 (not in øvelsessal 1)!

Predictive link between crop traits and ecoclimatic description of the original collecting site.

Dag Terje Filip Endresen

Nordic Genetic Resource Center (NordGen), Alnarp, Sweden


Biodiversity includes a rich diversity of different species adapted to a wide range of ecological conditions. Populations of species adapted to a subset of the species habitat are called ecotypes or ecospecies. Typically ecotypes show distinct phenotypic properties in response to their spesific ecological environment. Traditional crop cultivars can be seen as the agricultural equivalent of the ecotypes in wild species. Crop plants have evolved in response to the ecoclimatic and agricultural environment as human civilization developed and spread out across the planet. This phase of spread and adaption to new ecological conditions and new agricultural practizes resulted in a very large genetic diversity represented by distinct landraces of the crop species and has steadily progressed during the last 10 000 years. Modern plant breeding has reversed this steady increase in crop genetic diversity by the development of uniform modern high yielding cultivars outcompeting the diverse mosaic of previous landraces grown in the farming landscape around the world. During in particular the last fifty years this alarming effect of genetic erosion in the cultivated crops became increasingly more visible resulting in the systematic collection and conservation of the previous crop genetic diversity represented by the disapearing landraces. Under the coordination of the Food and Agriculture Organization of the United Nations (FAO) a network of international and national genebanks were established based on the model of the Russian Institute of Plant Industry located in Saint Petersburg (initiated in 1894 as the Bureau of Applied Botany).

These collections of crop genetic resources are today a valuable source of new genetic variation for economically important traits, including resistance to crop diseases. New sources of useful crop traits are often identified through evaluation in field trials, some of which may require special treatments such as inoculation for screening purposes. This has tremendous implications as it incurs costs. Further, the number of relevant accessions in genebank collections available to be evaluated for a specific trait is often substantially larger than the capacity or resources of the evaluation project. Thus, finding the genebank accessions most likely to posses the desired trait can be compared to searching for a needle in a haystack. The Focused Identification of Germplasm Strategy (FIGS) is an approach used to select subsets of germplasm from genetic resource collections in such a way as to maximize the likelihood of capturing a spesific trait at a higher frequency than if the subset had been selected at random. Michael Mackay originally proposed this subset selection strategy in 1990. Michael Mackay and Kenneth Street developed the strategy further in 2004 including the official naming as Focused Identification of Germplasm Strategy (FIGS).

The FIGS strategy uses a range of methods to link the expression of a specific trait (of a target crop) with the ecogeographic parameters of the original collection site. The results from a number of recent studies using the FIGS approach show that the climate layers from freely available ecogeographic databases are well suited to model and predict the reaction in these crops to biotic stress traits and other economically valuable crop traits. This result has the potential to improve the efficiency of field screening trials to find novel sources of economically valuable crop traits.

11 February: Nils Cronberg

Fertilization syndromes in bryophytes: Parallels to pollination syndromes in vascular plants.

Nils Cronberg

dept. Ecology, Section of Plant Ecology and Systematics, Lund University, Sweden

As a heritage from their algal ancestors, bryophytes (mosses, liverworts and hornworts) and early-divergent tracheophytes (lycophytes and pteridophytes) have motile sperm that need a water surface for transportation. This is considered to be a major evolutionary constraint in terrestrial environments. Thus, any character that improves fertilization efficiency would be strongly selected. In fact, several suites of characters that promote cross-fertilization, comparable to pollination syndromes in vascular plants, occur in various bryophytes. Splash-cup mechanisms take advantage of the force of falling water drops to increase the dispersal distance of sperm, which are hitchhiking with the split droplets. Phyllodioicy involves dwarf-sized males, which germinate and grow on normal-sized female plants, adjacent to female reproductive structures, thereby facilitating out-crossing at minimal sperm dispersal distances. Mechanisms that discharge airborne sperm are known from some liverworts. We have recently proved that microarthropods (springtails and mites) can assist in the transfer of sperm of the moss Bryum argenteum and thus mediate fertilization. We also have demonstrated that microarthopods are specifically attracted to fertile moss shoots. From these experiments we concluded that an animal-mediated fertilization syndrome similar to pollination in flowering plants occur in mosses. Bryophytes and microarthropods are evolutionarily much older than flowering plants and this fertilization syndrome is therefore potentially a precursor to pollination syndromes in flowering plants.

28 January: Stina Christensen & Christine Heimes

A reciprocal resistance system in two types of Barbarea vulgaris - An ecogenetic perspective.

Stina Christensen & Christine Heimes

dept. Agriculture and Ecology, Copenhagen University


Barbarea vulgaris (Brassicaceae) is a biennial or perennial herbal plant species, with a natural distribution in western Eurasia. In Denmark, the subspecies B.vulgaris ssp. arcuata occurs in two types, a hairy (Pubescent) P-type and a hairless (Glabrous) G-type. Populations of P- and G-type plants are found in all parts of Denmark, growing predominantly in separate patches. Hybrids between P- and G-type are rare, probably due to a partial reproductive barrier. The two plant types differ in morphological, cytological and chemical characters, and G-type plants are resistant to the flea beetle Phyllotreta nemorum, whereas P-type plants are susceptible. In contrast, G-type plants are susceptible to the oomycete pathogen Albugo candida, whereas P-type plants seem to be resistant.

Our talk will be based on the objectives of our PhD projects, aiming to entangle the role of resistance mechanisms in B. vulgaris from an ecological and genetic point of view:

• Is the geographical distribution of the two types caused by their belonging to two different evolutionary groups that occupied different refugia during the last ice age?

• Is the distribution of the P- and G-type populations in the landscape determined by different adaptations to local environmental conditions?

• Is resistance polymorphism in Danish B. vulgaris populations maintained by selection pressure exerted by the flea beetle P. nemorum and the oomycete A. candida?

• Is there a hybridization barrier and do hybrids have lower survival rates or lower fertility?

• Where in the genome does the Albugo-resistance map to, and what are the active defense compounds?

14 January: Inger Åhman

Plant to plant communication via volatiles

Inger Åhman

dept. Plant Breeding and Biotechnology, Swedish University of Agricultural Sciences, Alnarp

About 30 years ago two independent studies showed that volatiles from damaged plants may induce resistance to herbivores in neighbouring undamaged plants. These results were initially much debated, but were later confirmed in other plant species as well. During the last decade also volatiles from apparently undamaged plants have been found to induce changes in neighbouring plants, however only in certain genotype combinations. Efforts to unravel the mechanisms for this will be presented, using barley and the bird cherry – oat aphid as test organisms. Possibilities to apply these results for plant protection purposes will be presented.

3 December: Ronald Pierik

Plant Competition: regulation and functional significance of shade avoidance responses.

Ronald Pierik

Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, the Netherlands

Plants growing in dense vegetations compete for resources such as water, nutrients and light. Shade-intolerant plants ensure light capture through so-called shade avoidance responses to neighbors which include upward leaf movement and increased shoot elongation. Through these morphological acclimations, the photosynthetically active leaves are positioned relatively high in a vegetation where light availability is maximal.

Neighbor detection occurs predominantly through spectral changes in the light reflected from or transmitted through neighboring vegetation. Red light (R) is absorbed for photosynthesis whereas far-red light (FR) is reflected, thus lowering the R:FR ratio which can be sensed by the phytochrome photoreceptors. Low R:FR perception regulates a variety of hormones, such as auxin, gibberellin and ethylene, to control the adaptive growth responses. I will outline current insights into the regulatory components underlying these responses and their functional significance for shade avoidance and competitive power. Furthermore I will discuss how these insights can help ask and answer questions regarding ecological trade-offs, using current work on far-red light mediated repression of defense against pathogens as an example.

19 November: Erik Dahl Kjær & Lea Vig McKinney

Genetic resilience of natural populations of Fraxinus excelsior L. against novel Ash decline - are we losing a unique habitat?

Lea Vig McKinney*, Lene Rostgaard Nielsen, Jon Kehlet Hansen, Lars N. Hansen, Iben M. Thomsen, David B. Collinge, Erik Dahl Kjær*

*Forest & Landscape, Copenhagen University

Fraxinus excelsior is an important tree species native to the Danish flora. It provides commercial and environmental services, and is a key-stone species in natural plant communities associated with moist forest habitats on fertile soils. However, the health and viability the species is presently threatened by a novel emerging disease, presumably caused by the fungus Chalara fraxinea. The disease was observed in Denmark in 2003, and has since become common throughout the country causing devastating harms.

Since 2007, we have studied genetic variation between Fraxinus excelsior trees of Danish origin in their susceptibility to the disease. By studying clone and half sib progeny trials 2007-2010, inferring from both natural and artificial infection, and using pedigree reconstructions based on SSR markers, we have established estimates of genetic variation and narrow sense heritability in degree of susceptibility. Our 5 years time series also allows us to assess the progression of the damage at the given sites. In 2010, we have initiated additional monitoring of damage level in five Danish Fraxinus stands with various ages, including the 100+ years old Stasevang stand.

In the presentation we introduce what is known about the disease, and provide a brief account of our main findings. Based on the findings, we speculate on the nature and degree (if any) of resistance and resilience to be expected in Danish Fraxinus stands due to inherent variation in susceptibility. Implications for the likely future of the Danish Fraxinus forests are discussed.

5 November 2010: Niels Jacobsen

Is geographical closeness more important than morphological traits ?

Niels Jacobsen*, Conny Asmussen Lange, Jan Bastmeijer, Takashige Idei, Duangchai Sookchaloem, Fiorello Toneatto, and Marian Ørgaard.

*dept. Agriculture and Ecology, Copenhagen University

The MatK – and hopefully soon the ITS studies in Cryptocoryne will provide us with a general frame of relationships in the genus.

The aim of the AFLP studies in Cryptocoryne was to elucidate the genetic distances within species and species complexes: Some species of Cryptocoryne seem to be distinguished and understood rather easily (some of this “understood rather easily” may be due to insufficient material = too few samples). Other species have for a long time been more problematic i.e. morphologically variable.

The talk focuses on the C. beckettii complex (2n = 28, 42) from Sri Lanka, the C. cordata complex (2n = 34, 68, 102) from Malesia, and the C. crispatula complex (2n = 36, 54, 72) from Mainland Asia. The obtained results clearly point towards geographical closeness as an indicator of genetical closeness rather than morphological similarities. In the C. crispatula complex geographically distant and therefore genetically distant populations respond similarly to similar edaphic conditions, i.e. develop similar leaf-forms under similar edaphic conditions.

28 May 2010: Johannes Kollman

Challenges in restoration ecology - plans for future research in Munich

Johannes Kollmann

dept. Agriculture and Ecology, Copenhagen University


The current erosion in biodiversity and the degradation of ecosystem services are major challenges for biological conservation. Often conservation comes virtually too late, and restoration of impacted ecosystems is the only appropriate option. This has been realized for mining landscapes, postindustrial regions and degraded ex-arable land. More recently, urban ecosystems and infrastructure projects call for innovative planning strategies where ecologists, landscape planners and architects cooperate. Thus, restoration ecology is a young discipline which has developed in response to current environmental problems; it has a problem-oriented and interdisciplinary approach drawing on classical theories and recent advances in ecology. Some people call restoration ecology the “acid test” of ecological theory.

The Technical University Munich has established one of the first chairs in restoration ecology in Europe, and it offers a great chance to contribute to this research field in the coming years. In the seminar I want to summarize the work I have been doing in the past decade or so, and to describe the research plans I have when moving to Munich. I will try to make the presentation interesting to a non-specialist audience, and I would love to see all colleagues and other members of staff that have helped me during my time in Copenhagen.

23 April 2010: Tina D'Hertefeldt

Gene flow in Brassica napus: effects on herbivory, ferality and the seed bank

Tina D'Hertefeldt

dept. Plant Ecology and Systematics, Lund University, Sweden


Worldwide cultivation of oilseed rape (Brassica napus), which is second only to soybean for oil production, covered 28 million hectares in 2008. In Sweden, oilseed rape was grown on 110 000ha. With large land areas devoted to oilseed rape production, the crop becomes highly important to both natural and agricultural ecosystems. B. napus has been implemented as a species with high capacity for both volunteer and feral population establishment due to large seed production, long-term seed dormancy and potential for out-crossing with wild relatives.
The wild relative B. rapa ssp. sylvestris which was previously a common agricultural weed is now assumed to be threatened. Furthermore, varieties of genetically modified oilseed may be cultivated in the EU countries in future and it is therefore important to evaluate the effect of potential B. napus gene flow on wild B. rapa. The effects of increased insect resistance on wild B. rapa, and the roles of feral B. napus and the B. napus seedbank in spatial and temporal B. napus gene flow will be discussed.

09 April 2010: Honor Prentice

Studying diversity in a messy reality:
genes and species, ecology and adaptation, history and landscapes

Honor Prentice

dept. Plant Ecology and Systematics, Lund University, Sweden


Grassland ecosystems are beautiful, complex and extremely challenging to study. The structure of genetic variation within and between populations and its relationships with stochastic and adaptive processes on different spatial and temporal scales; the relationships between species richness and environmental, stochastic, historical and spatial processes; the relationships between genetic variation and plant community composition – how does everything fit together? Does it all fit together? I suggest that conservation biology in general, and conservation genetics in particular, should pay more attention to the possibility of local adaptation. And that studies of associations between biodiversity and environmental or historical variables need to include simultaneous analysis of a range of variables.

26 March 2010: Thure Hauser

Frequencies and effects of hybridisation between two arctic plant species: Pyrola grandiflora and P. minor

Thure P. Hauser

dep. Agriculture & Ecology, Copenhagen University


In the Arctic, hybridization, polyploidisation and introgression have been important for the evolution of the flora. With the predicted and ongoing change of climate, there will be an increased influx of plants from warmer parts of Eurasia and America. The fate of these newcomers, and of the resident species, will depend on the competitive and reproductive interactions between them.

Two species of Pyrola (Danish: vintergrøn) grow in Greenland. Both have a circumpolar distribution, but P. minor has a more southern distribution including Europe. At Disko Island on the west coast, P. minor has its northern limit, and hybridizes with P. grandiflora. In a project financed by the Carlsberg Foundation, we study the dynamics of hybridization between the two species to evaluate how hybridization may affect their distributions locally and regionally. Last summer we collected material to test if hybridization has led to integration of genetic material of one species into the other (introgression) by characterizing the genetic and morphological composition of local populations of the species. To test how easy it is for the two species to hybridize, we further did controlled pollinations between the species and hybrids and evaluated to what extent seeds are produced. In the coming summer, we will survey how often plants are actually pollinated, how well foreign pollen grows in the styles, and how successful hybrids grows in the habitats of the parental species.

12 March 2010: Bodil Ehlers

Adapting to your chemical neighbor: Thyme and its associated plants

Bodil K Ehlers

Institute of Biology, University of Southern Denmark


It is well known that plant allolochemicals can have profound effects on associated species, and that plants with a history of co-existence with chemical neighbour plants perform better in their presence compared to naïve plants. This suggests that plant communities may indeed be quite co-evolved and that associated plants may locally adapt to the presence of a “chemical neighbor” plant.

The genus Thymus is known for its production of aromatic compounds, whose main constitution is terpenes – mainly monoterpenes. The thyme genus has a genetic polymorphism for the production of these terpenes both within and among species. These monoterpenes are known to differentially affect performance of herbivores, soil-microorganisms, and the germination and growth of other plants. We have studies how associated plant species perform under the influence of thyme monoterpenes, and found that a number of plant species show an adaptive response to growing with their “home” terpene. In a recent study we demonstrated that associated plants show genetic variation for the sensitivity to thyme monoterpenes, and that this variation is in accordance with selection operating, thus suggesting that the presence of thyme plants in a community can act as a selective agent on the genetic variation of associated plants. Moreover, we have evidence that the outcome of the interaction with thyme and associated plants is strongly affected by the presence of soil microorganisms. I will present these findings and future plans and discuss how biotic interaction and intra species genetic variation can affect community structure and evolution.