SUMMARYAs photosynthesis is the basic process during which light energy is absorbed and converted into organic matter, the importance of the plant pigment chlorophyll (a and b forms) as an intermediary in transformation of the absorbed solar energy and its activity in the process of photosynthesis and synthesis of organic substances in plants are crucial. Therefore, this paper provides an overview of methods for monitoring the optical activity of chlorophyll molecules and methods (non-destructive and destructive) for quantification of chlorophyll in plants. These methods are used to estimate the effects of different stress factors (abiotic, biotic and xenobiotic) on the efficiency of photosynthesis and bioproductivity, aiming to assess the impact that these limiting factors have on the yield of various cultivars. Also, those methods for analysis of chlorophyll optical activity and/or content are appropriate for assessing the reaction of weed species to different agricultural practices (mineral nutrition, treatment by herbicides, etc.) and studies of different aspects of weed ecophysiology and their influence on crop harvest. Keywords: Chlorophylls; Photosynthesis; Plant health Abbreviations: LHCP 2 , LHCP 1 : antenna complexes in photosystems II and I with the main function of absorbing (sun)light quantum and converting it into excitation energy of chlorophyll molecules (excitons); PS II and PS I: photosystems II and I; RC: reaction centers of PS II and PS I with the function of transforming the energy of exciton into primary photochemical reaction

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Out of ca. 700 species belonging to Silene, 15 to 35 were classified in S. sect. Saxifragoideae. This section has its highest diversity on the Balkan Peninsula, which was the most important European Pleistocene refugium. The most widespread of the species is S. saxifraga ranging from the Pyrenees to the Carpathians. Together with ten morphologically similar taxa it is often treated as the S. saxifraga group, but the relationships among the taxa are unclear and blurred due to the occurrence of transitional forms. In this study, we used sequences of the nuclear ribosomal internal transcribed spacer (ITS) and the plastid rps16 intron as well as amplified fragment length polymorphisms (AFLPs) to elucidate phylogenetic relationships among the taxa belonging to—or hypothesized to be closely related to—S. sect. Saxifragoideae, covering the section’s entire geographical range. Phylogenetic analyses of 112 populations belonging to 33 taxa clarified previous classifications and showed that S. cephallenia, S. congesta, S. linoides, S. multicaulis, S. schwarzenbergeri and S. waldsteinii are clearly differentiated from all other taxa, which in turn form the newly circumscribed S. saxifraga group. Phylogenetic relationships within the latter are unresolved, and are governed by geographic proximity rather than by taxonomic identity. This is likely a result of recent rapid radiation and range expansion, as well as of convergent morphological evolution triggered by similar environmental selection pressures. The southern parts of the Balkan Peninsula are the centre of genetic diversity of the group, underlining the area’s importance as a sanctuary of diversification of European biota.

This study surveyed three species of the genus Armeria Willd. from five ultramafic outcrops, two non-ultramafic (schist) soils, and one tailing heap of an abandoned iron-copper mine from Serbia. Similarities and differences among the three Armeria species growing on different geological substrates in the ability to control uptake and translocate nine metals were examined. Chemical characteristics of the soil and plant samples (concentrations of PO KO, Ca, Fe, Mn, Ni, Zn, Cu, Cr, Co, Cd, and Pb) are presented. In order to assess accumulative potential of these three Armeria species, biological concentration, accumulation, as well as translocation factors were used. Three investigated Armeria species growing on eight different localities showed large differences in heavy metal uptake, translocation, and accumulation. The differences were present among the plant samples of the same species and even more among three different Armeria species and were primarily the result of the different contents of available heavy metals in the investigated soils. Additionally, differences might be the consequence of diverse responses and possible presence of supplementary resistance mechanisms in the plants from the ultramafic soils. None of the three Armeria species showed shoot hyperaccumulative potential for any of the investigated heavy metals and they could be considered as root accumulators, considering their potential to accumulate medium to large amounts of Zn (BCF up to 134), Cr (BCF up to 148), and Cd (BCF up to 9) in their roots.

The Balkan Peninsula is a hotspot of European biodiversity, harbouring many endemic species. Cerastium decalvans is a heteroploid species endemic to mountainous areas throughout the Balkan Peninsula. It is morphologically extremely variable, and multiple infraspecific taxa have been described. Mostly tetra-, octo- and hexadecaploids have been reported, but their distribution and relationship to morphological differentiation remain unknown. To disentangle relationships among 62 populations sampled across the distribution of the species, we applied an integrative approach. Using flow cytometry, we show that tetraploids are the most widespread cytotype, whereas octoploids are limited to the south-east of the distribution area and hexadecaploids occur mostly in high mountains of the central–eastern Balkan Peninsula. The main genetic break revealed by AFLPs separates uniformly tetraploid populations from the Dinaric Mountains in the north-west of the distribution area from the south-eastern populations. Based on our data we hypothesize multiple (auto)polyploidization events leading to the origin of octoploid populations and two allopolyploidization events leading to the origin of hexadecaploids. By combining genome size, AFLP and morphological data, we suggest recognition of five subspecies, of which we here describe hexadecaploid C. decalvans subsp. doerfleri subsp. nov. endemic to the Albanian Alps. In addition, the presence of several phylogenetic lineages and multiple ploidies with pronounced morphological variability in the southern and eastern Balkan Peninsula points to pronounced environmental stability of this area throughout the Quaternary, enabling survival and divergence in situ, and further supports the role of the Balkans as a sanctuary of plant diversification.