Plants have two principal defense mechanisms to decrease fitness losses to herbivory: tolerance, the ability to compensate fitness after damage, and resistance, the ability to avoid damage. Variation in intensity of herbivory among populations should result in variation in plant defense levels if tolerance and resistance are associated with costs. Yet little is known about how levels of toleran...

Host populations tend to show less ability to discriminate against parasites when living in their absence. However, comparison of rejection rates among sympatric and allopatric host populations does not allow determination of whether the greater tolerance in allopatric populations reflects a genetic change or phenotypic plasticity. Here we test the existence of changes in a host’s adaptation to...

This thesis is based on the following articles and manuscripts, which are referred to in the text by their Roman numerals: Mesocosms mimic natural meadows as regards greenhouse gas fluxes and potential activities of nitrifying and denitrifying bacteria. Plant and Soil 276: 287-299. soil microbial community structure under elevated tropospheric O 3 and CO 2. Submitted for publication. Difference...

In this study the in vitro cytotoxic properties of ethanol extracts from the herbs, inflorescents and roots of selected Asteraceae species: Arctium lappa, Artemisia absinthium, Calendula officinalis, Centaurea cyanus, Tanacetum vulgare and Tragopogon pratensis on J-45.01 human acute T leukemia cell line was examined. All tested samples possess antileukemic properties and induce cells death via ...

poa genus has a high value for grazing and forage conservation concerning thelivestock. in order to study the impacts of cold temperature and growing degree days(gdd) on seedling morphological trait and phonological development of two speciesinvolving poa pratensis and poa trivialis, this research was conducted in laboratory andgreenhouse and outdoor of research institute of forest and rangelan...

Tragopogon mirus and T. miscellus (both 2n = 4x = 24) are recent allotetraploids derived from T. dubius × T. porrifolius and T. dubius × T. pratensis (each 2n = 2x = 12), respectively. The genome sizes of T. mirus are additive of those of its diploid parents, but at least some populations of T. miscellus have undergone genome downsizing. To survey for genomic rearrangements in the allopolyploid...

This study examines phylogenetic relationships among six species of the Formica rufa group ants (F. polyctena, F. rufa, F. lugubris, F. paralugubris, F. aquilonia, and F. pratensis). The phylogeny based on a 2051bp fragment of mtDNA including cyt b, tRNASer, and ND1 genes supports the division of the group into three major clusters: one with the species F. polyctena and F. rufa, one with F. aqu...