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The paper presents results of biosystematic analysis of the critical group of Caltha palustris L. based on 71 populations from Poland. After a preliminary statistical analysis, fourteen morphological characters (nine quantitative and five qualitative), describing size and shape of basal leaves and mature follicles as well as stem morphology, were selected for the clearest differentiation of the complex. Several groups of morphotypes were distinguished within the complex, based on the statistical analysis of this group of characters. Against this background the taxonomy of the complex is proposed. Two species - Caltha laeta Schott, Nyman and Kotschy and Caltha palustris L. - and three subspecies within C. palustris (C. p. subsp. palustris, C. p. subsp. cornuta (Schott, Nyman and Kotschy) Hegi and C. p. subsp. radicans (T.F. Forst.) Syme, were distinguished in Poland. The status of the taxa within the Polish flora is defined. The paper includes also a key for determination of the complex taxa, as well as their detailed descriptions.
Fragmented distribution, the breeding system and effects of genetic drift in small-size populations occurring at edge of the species range play an important role in shaping genetic diversity of such a species. Melica transsilvanica is a plant rare in the flora of Poland, where it reaches the northern limit of its continuous range. Amplified Fragment Length Polymorphism (AFLP) DNA profiling method was applied to measure genetic diversity among and within populations of M. transsilvanica. Additionally, genetic relationships between M. transsilvanica and Melica ciliata, two closely related species, were explored. A total of 68 plants from 7 populations of M. transsilvanica and 24 plants from 2 populations of M. ciliata, collected in Poland and outside it, were analyzed. Using 294 AFLP fragments from 3 primer combinations, accessions were grouped into two major clusters associating with M. ciliata and M. transsilvanica, respectively. Further, two subclusters, corresponding to the samples collected from the Pieniny Mts and from the Kraków - Częstochowa Upland were clearly distinguished within the M. transsilvanica group. The hierarchical AMOVA exhibited significant genetic distinction between these geographic regions (60.89%, p < 0.001). The obtained results showed that the most genetic diversity resided between the populations of M. transsilvanica (86.03%) while considerably lower genetic variation was found within the populations (13.97%), which is consistent with the results reported for self-plants. The low level of AFLP genetic variation of M. transsilvanica can be caused by the geographic isolation of populations, which preserves the dominant self-mating breeding system of the species. Individual populations of M. transsilvanica are characterized by isolated gene pools differing by a small number of loci.
A good knowledge of species delimitation is crucial for the biodiversity protection and the conservation of wild species. We studied the efficiency of AFLP markers and morphological characters to assist species determination for Melica ciliata L. and M. transsilvanica Schur within European range of distribution, including isolated and range-limit populations of "M. ciliata" (i.e. M. cf. ciliata) from the Polish Sudetes, where it is regarded as critically endangered. AFLP markers were found to be more effective then morphological characters (more or less continuous) in distinguishing the both studied species. AMOVA revealed very low genetic diversity within populations and high differentiation among populations of M. ciliata and M. transsilvanica (FST = 0.89 and 0.95, respectively). The species-diagnostic AFLP markers of M. transsilvanica shared with "M. ciliata" from the Sudetes were detected. On the other hand, no species-diagnostic genetic markers of M. ciliata or hybrid-diagnostic markers of M. × thuringiaca were found within "M. ciliata". PCoA and NJ showed an overlapping genetic diversity of "M. ciliata" and M. transsilvanica. Hierar­chical AMOVA supported the absence of a significant genotypic distinction between "M. ciliata" and M. transsilvanica. ANOVA showed that the length ratio of lower to upper glumes was the best morphological character to discriminate between M. ciliata and M. transsilvanica. Combined morphological and genetic data show that M. ciliata is not currently present in Poland as its putative Polish populations represent M. transsilvanica. A significant decrease in genetic varia­bility that could influence viability was not observed the in Sudetian populations of M. transsilvanica. However, the population size changes significantly as a result of plant succession. Correction of the northern limit of the continuous distribution of M. ciliata L. in Central Europe is presented.
Geographically marginal populations are expected to have low genetic variability, which potentially can affect their viability. In Poland Melica transsilvanica Schur reaches the northern limit of its continuous geographical range. Genetic diversity and population genetic structure were analyzed in 15 of its marginal and more central populations using AFLPs. Overall, genetic diversity parameters did not differ significantly, and comparable patterns of genetic variation were found in central and marginal populations. All AFLP phenotypes were unique to particular populations. Unique alleles were fixed in some central and some marginal populations. The percentage of polymorphic loci varied from 1.30 to 5.19 (3.24 average) in central populations and from 0.43 to 5.63 (2.36 average) in marginal ones. Hierarchical analyses of molecular variance (AMOVA) for each species/region combination revealed highly significant differentiation between populations and showed similar partitioning of molecular variance in marginal and central populations of M. transsilvanica (diversity between populations: 93.24% and 93.18%, p < 0.001, respectively). The scattered distribution of suitable species habitats and the predominant selfing breeding system of the species strengthen the effect of selection pressure on fixation of unique loci in individual populations. Marginal populations of M. transsilvanica with unique alleles considerably expand the genetic variation of the species and are therefore valuable for conservation of genetic diversity.
Galium sect. Leptogalium Lange in NE Europe is represented by few, local endemic species which occur in the area covered by the continental ice sheet in the Pleistocene period. They are: G. cracoviense Ehrend. in S Poland, G. oelandicum (Sterner & Hyl.) Ehrend. in SE Sweden and G. sudeticum Tausch in SW Poland and N Czech Republic. 55 individuals from five populations of these species were analysed using AFLP markers. A total of 193 AFLP bands were detected using three combinations of primers; out of them 159 proved polymorphic (82.4%). The lowest values of Shannon's index and Nei's gene diversity were noted for G. oelandicum and the highest ones for G. sudeticum. The results indicate a relatively high level of genetic variability in each of endemic species in spite of that the studied species occupy very small areas and are represented by a low number of populations. We conclude that additional, demographic and genetic studies are necessary to monitor potential decrease of populations' size resulting mainly from the mechanical destruction of plants and their habitats caused by intense tourism or other human activities (as agriculture, e.g. grazing).
Genetic diversity of Galium cracoviense, a narrow endemic species, limited to the small area in southern Poland and concentrated on Jurassic limestone outcrops near Częstochowa, was examined using the AFLP marker. Twenty nine individuals from three spatially isolated populations were used for the study. AFLP analysis yielded 157 bands, of which 110 (70%) were polymorphic. The AMOVA analysis revealed a substantially higher variation within populations (89.35%) than among them (10.65%). Values of parameters describing population genetic diversity, such as Shannon index and gene diversity index estimated for each population, were highly similar. The results indicate a high level of genetic polymorphism as well as a high genetic similarity of the isolated populations of G. cracoviense and thus an unconstrained gene flow between them. Based on the results we conclude that additional demographic and genetic studies, are necessary to monitor potential decrease of populations size resulting mainly from the mechanical destruction of plants and their habitats caused by intense tourism. Due to the small general range of occurrence, conservation should include the highest possible number of populations of G. cracoviense.
The results of variability analysis of basal leaf epidermis stomata in the Caltha palustris L. complex are presented. Stoma length and width were measured in material from 17 Polish localities. In C. palustris subsp. laeta the stomata are clearly elongated and bigger (mean length 56.52 ± 8.41 µm) than those of subsp. palustris (mean length 46.80 ± 6.73 µm). Within the latter subspecies, in the sample determined as var. radicans they are only slightly longer (mean length 51.46 ± 5.46 µm) than wide (mean width 46.20 ± 5.25 µm), while in var. comuta they are distinctly longer (mean length 52.45 ± 5.17 µm) than wide (mean width 45.00 ± 3.86 µm); both, however, are more circular than in subsp. laeta.
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