Parazitické rostliny získávají vodu, minerální živiny a organický uhlík od svých hostitelů pomocí specializovaných struktur – haustorií, která jsou u většiny druhů nápadně podobná. Klíčovou vlastnost však představuje mechanismus napojení na cévní svazky hostitele, který je do značné míry charakteristický pro jednotlivé funkční skupiny a evoluční linie parazitických rostlin. and Parasitic plants acquire water, mineral nutrients and organic carbon from their hosts via specialized organs called haustoria, which are strikingly similar among individual species. However, the contact mechanism between the host and parasite vascular systems presents the key feature characteristic of individual functional groups and evolutionary lineages of parasitic plants.
The Melampyrum sylvaticum group is a complex of three closely related species. This group is most variable in the Carpathian region. Interactions among different levels (within-population to interspecific) of genetic variation and influence of the environment are considered to be the main sources of the complicated morphological variation in this region. Morphological variation in the M. sylvaticum group was studied in mountain ranges of the Hercynian Massif and in the Western and Ukrainian Carpathians. Several populations were sampled at different altitudes within each mountain range. Hierarchical partitioning of morphological variation at different levels (within populations, among populations within a mountain range and among mountain ranges) was calculated. Correlations among groups of morphological characters and altitude were calculated. The largest proportion of variation on a large geographic scale (i.e. among mountain ranges) was detected in anther length and several corolla characters (length of the lower corolla lip, height of upper corolla lip), whereas these traits were homogeneous at a local scale (within populations and among populations in one mountain range). An opposite pattern (i. e. high proportion of variation at the low levels, which blurred possible large scale differences) was found in bract traits and several calyx characters. Moreover, a strong correlation between bract length and altitude was observed. The observed changes in the proportions of morphological variation and response to altitude suggest a close connection between bract characters and environmental factors (or lower levels of genetic variation). On the other hand, some of the flower characters seem to be genetically determined and thus might reflect evolutionary processes (early diversification, potential hybridization, introgression) on which the taxonomic treatment of the group should be based. The most distinct differences were detected between samples from the Ukraine and south-western part of Bohemia. Populations from the the Sudeten Mts and the Western Carpathians were variable and morphologically intermediate, forming a continuum between the two extremes.
Parazitické rostliny představují velmi specifickou skupinu v rámci rostlinné říše, jejíž zástupci jsou jinak autotrofní. V průběhu evoluce vynalezly tyto rostliny mnoho způsobů parazitismu na zdrojích, strukturách a službách, ve kterých využívají jiných rostlin, hub nebo dokonce živočichů. V článku jsou definovány jednotlivé funkční skupiny parazitických rostlin a stručně popsána jejich biologie. and Parasitic plants present a very specific group among otherwise autotrophic representatives of the plant kingdom. During evolution, these plants invented different ways of parasitism on resources, structures and services, exploiting other plants, fungi and even animals. Individual functional groups of parasitic plants together with their biology are described in the article.
We investigated variation in the Melampyrum sylvaticum group in the Carpathian and Hercynian regions using morphological and molecular tools. The aim of our study was to examine differences in the pattern of variation between the Eastern Carpathians and region of theWestern Carpathians and the Hercynian Massif. We also tested correlations between putatively taxonomically important variation in corolla colour present in the Melampyrum sylvaticum group in the Eastern Carpathian region and other morphological and molecular traits. Samples were collected from populations of the M. sylvaticum group in the Hercynian Massif and the Eastern and Western Carpathians. Morphometric analyses of the size and shape of the corolla (based on thin plate spline with sliding semilandmarks), length of the anthers and especially molecular analyses based on sequencing the nuclear ITS and trnL-trnT regions of chloroplast DNA, confirmed that the populations occurring on the opposite sides of the Eastern-Western Carpathian biogeographic boundary are very different. It is likely that the eastern and western lineages have been isolated for a long time and the extant pattern of variation with character disagreement within the border zone, originated from hybridization and introgression. The differences in corolla colour did not coincide with the variation in morphological traits or molecular markers within the North-Eastern Carpathian region. In addition, the geographical distribution of the populations with contrasting corolla colours lacked any pattern and there are populations with both corolla colours as well as plants with transitional pale-yellow flowers. Therefore, it is suggested that M. saxosum and M. herbichii, microspecies delimited on the basis of corolla colour, are conspecific. The high level of molecular variation and its pattern indicate that the M. sylvaticum group may have survived in or near the Eastern Carpathians during the Weichselian Ice Age. This hypothesis is supported by several recent phytogeographical and palaeoecological studies, which indicate the existence of a glacial refuge in the Eastern Carpathian region. Molecular uniformity of theWestern Carpathian and Hercynian populations might in contrast indicate recent (Holocene) migration from assumed perialpine refuges.