<b>Cardamine hirsuta</b> L. is an emerging model system in developmental genetics, where natural genetic variation within <b>C. hirsuta</b> provides the means to investigate the genetic basis of morphological traits. This thesis investigates the geographical structure and genealogical history of genetic variation within <b>C. hirsuta</b> and identifies its closest relatives. This will enable the accurate selection of species for comparison with <b>C. hirsuta</b> when making interpretations of evolutionary processes, and provide a better understanding of morphological character evolution in <b>C. hirsuta</b>. The phylogeographic history of <b>C. hirsuta</b> was reconstructed using multiple chloroplast and nuclear markers and widespread accession sampling from across its native range. A distinct group was identified within <b>C. hirsuta</b>, restricted to the high mountains of East Africa. Climate suitability modelling showed that Pleistocene glacial dynamics have had a strong effect on the distribution of genetic variation within <b>C. hirsuta</b>. The phylogeographical data generated here was used to investigate the origin of <b>C. hirsuta</b> in the Azores, an oceanic archipelago. The Azores are dominated by an endemic chloroplast haplotype which is associated with an endemic phenotype. Thus, <b>C. hirsuta</b> appears to have diversified <b>in situ</b> in the Azores. Phylogenetic analyses of Cardamine, restricted to diploid species to remove the confounding effects of polyploids, found that <b>C. hirsuta</b> is most closely related to <b>C. oligosperma</b>, a western North American species. Multiple loci and extensive intraspecific sampling were brought to bear to demonstrate that <b>C. hirsuta</b> and <b>C. oligosperma</b> are reciprocally monophyletic. <b>Cardamine pattersonii</b>, a restricted endemic from north-west Oregon is likely to be an allopolyploid, with <b>C. oligosperma</b> as the maternal parent and possibly <b>C. nuttallii</b> as the paternal parent.

Une grande diversité de formes foliaires caractérise le monde végétal. Cette diversité s'étend des feuilles simples avec des marges lisses aux feuilles composées, avec des marges disséquées. Cependant, les dentelures des marges de ces feuilles simples ou composées se développent en suivant un mécanisme similaire. Ce mécanisme repose sur l'action des gènes NO APICAUX MERISTEM/ CUP-SHAPED COTYLEDONS (NAM/CUC) ainsi que sur la voie auxinique. Chez Arabidopsis, qui possède des feuilles simples, un équilibre entre les expressions de CUC2 et de son répresseur, miR164, est nécessaire au bon développement des dents. Nous avons montré qu'un autre membre de la famille CUC, CUC3, contribue également au développement de ces dents chez Arabidopsis. Bien que son action soit principalement dépendante de CUC2, il agit également plus tard au cours du développement foliaire. En outre, nous avons démontré qu'une boucle de rétro-contrôle entre CUC2 et la voie auxinique permet le développement de dents avec plus ou moins marquées. Nous avons également montré qu'un modèle d'expression temporelle existe entre l'auxine et le module CUC2-miR164. En outre, la production de plantes transgéniques de Cardamine hirsuta, un proche parent d' Arabidopsis, qui possède des feuilles composées, a mis en évidence l'importance des éléments cis-régulateurs dans le promoteur de CUC1 de Cardamine hirsuta. En effet, la divergence de ces éléments cis-régulateurs entre les promoteurs de CUC1 de Cardamine hirsuta et d' Arabidopsis pourrait expliquer que CUC1 soit fortement exprimé dans les feuilles de Cardamine hirsuta alors qu'il est faiblement exprimé dans celles d' Arabidopsis. / A wide diversity of leaf shapes characterises the plant world. This diversity ranges from simple leaves with smooth margins to compound leaves with dissected margins. However, all serrations of simple or compound leaf margins are developed using a similar mechanism. This mechanism includes the action of the NO APICAL MERISTEM/CUP-SHAPED COTYLEDON (NAM/CUC) genes as well as the auxin pathway. In Arabidopsis simple leaves, a balanced expression of CUC2 and its repressor miR164 is controlling the serrations development. We have shown that another member of the CUC family, CUC3, also contributes to the serration development in Arabidopsis simple leaves. While its action is mainly dependent of the one of CUC2, it also acts later during leaf development. Additionally, we have demonstrated that a feed-back loop was regulating the CUC2 and auxin pathways, in order to form leaves with more or less incisions. We also shown that a temporal expression pattern was established between the auxin and the CUC2-miR164 module. Moreover, generation of transgenic Cardamine hirsuta plants, a close relative of Arabidopsis, that possesses compound leaves, has enlighten the importance of cis-regulatory elements in the promoter of CUC1 from Cardamine hirsuta. Indeed, the divergence of cis-regulatory elements between promoters of CUC1 from Cardamine hirsuta and Arabidopsis could explain that CUC1 is expressed strongly in Cardamine hirsuta leaves whereas it is weakly expressed in Arabidopsis leaves.

Repeated polyploidization events are thought to be among the most important causes of sympatric speciation throughout evolutionary time. Changes in phenology and trait expressions that arise in polyploids have been shown to affect plant interactions with insect herbivores and pollinators. If these interactions are changed, selection subsequent to the polyploidization event could contribute to further divergence, or increased similarity, of cytotypes. This study was conducted to investigate plant interactions with insect herbivores and pollinators and patterns of selection in tetraploid and octoploid Cardamine pratensis L. (Brassicaceae), and to answer the following questions: i) Is there phenotypic selection on flowering phenology and number of flowers? ii) Is pollen limitation or herbivory most important for variation in reproductive output? iii) During what stages of ovary and ovule development do variation in fitness mainly arise? iv) Can the intensity of interactions be linked to phenology and number of flowers, suggesting that selection is mediated by pollen limitation or herbivory? v) Do intensity of interactions, and of interaction-mediated selection, differ between ploidy levels? From a combination of an observational study of herbivory and a hand pollination experiment, selection was found for earlier flowering in both subspecies. Intensity of herbivory was an important determinant of plant reproductive success, while hand pollination had little effect. Positive effects of flowering time on intensity of herbivory suggest that selection for earlier flowering was mediated by herbivores. Tetraploids initiated flowering later and suffered from more intense herbivory than did octoploids. The direction of selection was similar in both subspecies. However, differences strength of selection and intensity of herbivory suggest that there is a possibility of selection for their further divergence. / Polyploidisering anses vara en av de viktigaste orsakerna till artbildning inom populationer. Skillnader i blomningskaraktärer, såsom fenologi och blomantal, som uppstår i och med polyploidiseringen har visat sig påverka växters interaktioner med såväl pollinatörer som herbivorer. Förändringar i växt-insektsinteraktioner till följd av polyploidiseringen kan leda till selektion för ökade skillnader, eller likheter, mellan cytotyper. Studiens syfte var att undersöka växters interaktioner med insekter i form av pollinatörer och herbivorer, samt att undersöka selektionsmönster hos tetraploida och oktoploida Cardamine pratensis L. (Brassicaceae). Jag ville även besvara följande frågor: i) Sker selektion på blomningstid och blomantal? ii) Vilken växt-insektsinteraktion är viktigast för variation i reproduktionsframgång? iii) Under vilka utvecklingsstadier uppstår den största variationen i fitness? iv) Kan intensiteten av interaktionerna kopplas till blomningsfenologi och blomantal, vilket skulle indikera att selektion förmedlas genom pollenbegränsning eller herbivori? v) Skiljer sig styrkan av interaktionerna, och av interaktionsförmedlad selektion, mellan ploidinivåer? Studien utformades som en kombination av en observationsstudie av herbivori och ett handpollineringsexperiment, och jag fann selektion för tidigare blomning hos de två underarterna. Reproduktionsframgång styrdes av herbivori snarare än pollenbegränsing. Förlust av potentiell fitness genom att fröämnen inte utvecklades till frön var den faktor som starkast påverkade variation i fitness, och detta var också den fas i utvecklingen som bidrog i störst utsträckning till kvantitativ förlust av fitness. Ett positivt samband mellan blomningsfenologi och herbivoriintensitet indikerar att selektion för blomningstid var förmedlad av herbivorer. Tetraploider blommade senare och utsattes för mer intensiva herbivorattacker än oktoploider. Detta, samt skillnader i selektionsstyrka, indikerar att selektion skulle kunna leda till ökad divergens av underarterna.

Yes / The coexistence of hermaphrodites and female-sterile individuals, or androdioecy, has been documented in only a handful of plants and animals. This study reports its existence in the plant species Cardamine amara (Brassicaceae), in which female-sterile individuals have shorter pistils than seed-producing hermaphrodites. Morphological analysis, in situ manual pollination, microsatellite genotyping and differential gene expression analysis using Arabidopsis microarrays were used to delimit variation between female-sterile individuals and hermaphrodites. Female sterility in C. amara appears to be caused by disrupted ovule development. It was associated with a 2.4- to 2.9-fold increase in clonal propagation. This made the pollen number of female-sterile genets more than double that of hermaphrodite genets, which fulfils a condition of co-existence predicted by simple androdioecy theories. When female-sterile individuals were observed in wild androdioecious populations, their ramet frequencies ranged from 5 to 54 %; however, their genet frequencies ranged from 11 to 29 %, which is consistent with the theoretically predicted upper limit of 50 %. The results suggest that a combination of sexual reproduction and increased asexual proliferation by female-sterile individuals probably explains the invasion and maintenance of female sterility in otherwise hermaphroditic populations. To our knowledge, this is the first report of the coexistence of female sterility and hermaphrodites in the Brassicaceae.

<p>Tolerance to herbivory is the ability of plants to maintain fitness in spite of damage. The goal of this thesis is to investigate the genetic variation and expression of tolerance within species, determine whether and in what conditions tolerance has negative side-effects, and how tolerance is affected by different ecological factors. Tolerance is investigated with special focus on the effects of different damage types, competitive regimes, history of herbivory, and polyploidization in plants. Studies are conducted as a literature review and three experiments on two cruciferous species Raphanus raphanistrum and Cardamine pratensis.</p><p>In the tolerance experiments, plants are subjected to artificial damage solely, or in a combination with natural damage. A literature review was conducted in order to investigate the effects of damage method. We found that traits related to tolerance, such as growth and fitness were not as sensitive in regard to damage method as measures of induced chemical traits, or measures of secondary herbivory.</p><p>Genetic variation of tolerance was demonstrated within populations of R. raphanistrum and between subspecies of C. pratensis. In R. raphanistrum, traits involved in floral display and male fitness were positively associated with plant tolerance to herbivore damage. A potential cost of tolerance was demonstrated as a negative correlation between levels of tolerance in high and low competitive regimes. I found no evidence of other proposed costs of tolerance in terms of highly tolerant plants suffering of reduced fitness in the absence of herbivores or trade-offs in terms of a negative association between tolerance to apical and leaf damage, or between tolerance and competitive ability. In C. pratensis, higher ploidy level in plants involved higher levels of tolerance measured as clonal reproduction. Furthermore, populations exposed to higher levels of herbivory had better tolerance than populations exposed to lower levels of herbivory. In this thesis, I demonstrate evidence of different components for the evolution of tolerance in plants: genotypic variation, selective factors in terms of costs and ploidization, and selective agents in terms of changing environment or herbivore pressure.</p>

Tolerance to herbivory is the ability of plants to maintain fitness in spite of damage. The goal of this thesis is to investigate the genetic variation and expression of tolerance within species, determine whether and in what conditions tolerance has negative side-effects, and how tolerance is affected by different ecological factors. Tolerance is investigated with special focus on the effects of different damage types, competitive regimes, history of herbivory, and polyploidization in plants. Studies are conducted as a literature review and three experiments on two cruciferous species Raphanus raphanistrum and Cardamine pratensis. In the tolerance experiments, plants are subjected to artificial damage solely, or in a combination with natural damage. A literature review was conducted in order to investigate the effects of damage method. We found that traits related to tolerance, such as growth and fitness were not as sensitive in regard to damage method as measures of induced chemical traits, or measures of secondary herbivory. Genetic variation of tolerance was demonstrated within populations of R. raphanistrum and between subspecies of C. pratensis. In R. raphanistrum, traits involved in floral display and male fitness were positively associated with plant tolerance to herbivore damage. A potential cost of tolerance was demonstrated as a negative correlation between levels of tolerance in high and low competitive regimes. I found no evidence of other proposed costs of tolerance in terms of highly tolerant plants suffering of reduced fitness in the absence of herbivores or trade-offs in terms of a negative association between tolerance to apical and leaf damage, or between tolerance and competitive ability. In C. pratensis, higher ploidy level in plants involved higher levels of tolerance measured as clonal reproduction. Furthermore, populations exposed to higher levels of herbivory had better tolerance than populations exposed to lower levels of herbivory. In this thesis, I demonstrate evidence of different components for the evolution of tolerance in plants: genotypic variation, selective factors in terms of costs and ploidization, and selective agents in terms of changing environment or herbivore pressure.

No description available.

This thesis summarizes the documented information on the distribution of Cardamine dentata Schult. of the family Brassicaceae in the Czech Republic; it deals with the chromosome numbers and with ploidy levels of this species. Microsatellite markers were used to evaluate the potential relationships of C. dentata with other species of the group C. pratensis. Using a revision of available herbarium material it was found that the optimal conditions for the occurrence of C. dentata in the Czech Republic are in the phytogeographical regions of Thermophyticum and Mezophyticum at altitudes of 150-650 m a.s.l. No karyological data on this species were previously published from the area of the Czech Republic; using the flow cytometry and chromosomes counting it was revealed that in the area of the Czech Republic, populations with decaploid and undecaploid levels of ploidy occur. With help of microsatelite markers, it was confirmed that plants of C. dentata are genetically different from the other species of the C. pratensis group. Keywords: Cardamine, Cruciferae, microsatelite markers, chromosome numbers, geographical distribution, Czech Republic

Dispersal is a key trait across biology. Within plants, a variety of explosive seed dispersal mechanisms are seen. Whilst ecological and mechanical studies have described this important evolutionary adaptation in many species, a genetic and developmental understanding of explosive seed dispersal is lacking. In this thesis, the morphology and development of the explosive seed pods of Cardamine hirsuta – a member of the Brassicaceae – are characterised in detail, with reference to its close relative, the model organism A. thaliana. Comparison of fruit morphology between these two species and across other Brassicacean species generated hypotheses regarding the function and polarity of morphological features. In order to identify genes that are necessary for C. hirsuta fruit development, a genetic screen was conducted and a range of mutants identified and subsequently characterised. Analysis of the indehiscent valveless (val) mutant revealed a loss of valve tissue and an expansion of valve margin identity in the silique. Mapping and sequencing identified a mutation in the MADS-box gene FRUITFULL (FUL), which results in a truncated protein, as the likely cause of the val phenotype. Consideration of ful mutants in C. hirsuta and A. thaliana allowed comparison of the genetic patterning of the fruit dehiscence zone in these two species. The genetic interactions between fruit mutants characterised in this thesis and mutants in shoot patterning genes revealed common regulatory networks underlying leaf and fruit development in C. hirsuta. Together, comparison of wild-type and mutant C. hirsuta siliques with those of A. thaliana and other Brassicacean species suggests that specialised cell layers within the valve silique region are of key importance to C. hirsuta’s explosive dehiscence mechanism.

The strength and direction of interactions between organisms vary spatially across the landscape. Traditionally, the focus has been on how trait variation affects the interactions between species. However, differences in abiotic and biotic environmental factors may also alter the distribution, phenology and behavior of the interacting species. To be able to understand why an interaction varies across the landscape, the effects of trait variation has to be separated from the effects of the environmental context. In this thesis, I try to separate the effects of context and trait differences on plant resistance against herbivory, through experimental and observational studies conducted with two cytotypes of the perennial herb Cardamine pratensis and its main herbivore, Anthocharis cardamines. The results show that differences in plant resistance against oviposition under controlled conditions were mainly mediated by flower size; larger flowers were more attractive to the female butterfly. However, among-populations differences in oviposition under natural conditions were not related to the resistance observed under controlled conditions, or to ploidy type, flowering phenology or plant size. Within populations under natural conditions the oviposition patterns by A. cardamines was affected by the plant traits plant size and flowering phenology. The result of this thesis shows that among-population differences in intensity of plant-herbivore interactions were caused by differences in environmental context rather than by herbivore preferences for any phenotypic plant traits, while host plant selection within population was based on plant traits. This suggests that biotic and biotic context can have important effects on the intensity of plant-herbivore interactions. Although genetic traits influenced the outcome of the interaction within populations, it was the environmental context of the populations that determined largely if the interaction took place or not. / <p>At the time of the doctoral defence the following papers were unpublished and had  a status as follows: Paper 2: Manuscript in review in Plos One; Paper 3: Manuscript in review in <em></em>Ecological Entomology; Paper 4: Manuscript</p>