Abstract:The results of research into leaf stomatal variability of five European beech provenances originating from Austria, Bosnia and Hercegovina, Germany, Romania and Serbia are presented in this paper. Aim of the study was to investigate how stomatal traits of provenances originating from different environments change in response to drought stress and to assess the phenotypic plasticity of the stomatal features investigated. The study was conducted during two different years, characterized by contrasting weather conditions (2010 and 2011). Two-way ANOVA revealed that provenances differ significantly in terms of stomatal density (SD), width of stomatal aperture (W b ), potential conductance index (PCI) and relative stomatal pore surface (RSPS), during both seasons. In a dry year (2011) all provenances significantly increased stomatal density by between 16.1% (Hasbruch -DE) and 21.9% (Cer -SRB). Guard cell length (L A ) was not statistically different among provenances in either year (2010 and 2011), even though L A decreased in the dry year (2011) in all provenances. Reaction norms were steep in most of the parameters suggesting the possibility of a plastic response of provenances toward changes in soil water regime, influenced by the prevailing weather each year. Phenotypic plasticity indices were the highest in regards of SD, PCI and RSPS, indicating that these traits would be good candidates for improvement in breeding programs aimed at selection of drought resistant.

To better understand what directs and limits the evolution of phenotype, constraints in the realization of the optimal phenotype need to be addressed. That includes estimations of variability of adaptively important traits as well as their correlation structures, but also evaluation of how they are affected by relevant environmental conditions and development phases. The aims of this study were to analyze phenotypic plasticity, genetic variability and correlation structures of important Iris pumila leaf traits in different light environments and ontogenetic phases, and estimate its evolutionary potential. Stomatal density, specific leaf area, total chlorophyll concentration and chlorophyll a/b ratio were analyzed on I. pumila full-sib families in the seedling phase and on the same plants after 3 years of growth in contrasting light conditions typical for ontogenetic stage in question. There was a significant phenotypic plasticity in both ontogenetic stages, but significant genetic variability was detected only for chlorophyll concentrations. Correlations of the same trait between different stages were weak due to changes in environmental conditions and difference in ontogenetic reaction norms of different genotypes. Ontogenetic variability of correlation structures was detected, where correlations and integration were higher in seedlings compared with adult plants 3 years later. Correlations were affected by environmental conditions, with integration being higher in the lower light conditions, but correlations between phases being stronger in the higher light treatment. These findings demonstrated that the analyzed traits can be selected and can mostly evolve independently in different environments and ontogenetic stages, with low genetic variability as a potentially main constraint.

In this study, we analyzed fluctuating asymmetry (FA) of black locust (Robinia pseudoacacia) leaf traits as a measure of developmental instability in polluted and unpolluted habitats. We aimed to evaluate the potential of this method as a biomarker and its applicability on widely distributed species under in situ conditions. Leaf samples were taken from seven sites--three categorized as unpolluted (natural protected and rural) and four categorized as polluted covering the broad spectrum of intense pollution (industrial and traffic), from 1,489 individual trees in total. Results revealed significant differences in FA with expected higher values in polluted environments. Applicability of FA of R. pseudoaccacia leaf traits as a biomarker for testing potential pollution level, as well as the amount and distribution of sampling effort needed for its application, are discussed.

We analyzed genetic variability and phenotypic plasticity of flowering pattern and reproductive success in 97 clonal genotypes of Iris variegata originating from contrasting light habitats in Deliblato Sands and expressed under different experimental light conditions. Rhizome segments were taken from each of these clones and transplanted in the experimental garden near the Institute for Biological Research in Belgrade. Significant differences between genotypes were found for two traits (start of flowering, average flowering time). Genotypes originating from open and understory habitats significantly differed for three traits (number of flowers, number of capsules/number of flowers, seed mass/capsule). Significant effect of light treatment were found for three traits (number of capsules/number of flowers, seed mass/capsule, average seed mass). Statistically significant correlations between explored traits were generally similar but also to some extent habitat and treatment specific. Comparing these results with research carried out on congeneric species we noted that there are similar responses for some traits, but also significant differences in some components of flowering and fruiting success. [Projekat Ministarstva nauke Republike Srbije, br. 173025: Evolution in heterogeneous environments: mechanisms of adaptation, biomonitoring and conservation of biodiversity]

In this study we compared the biomonitoring potential of various types of flower asymmetry indices in Iris pumila (Dwarf Bearded Iris). We chose 197 naturally growing clones from the arid steppe habitat in the largest sandy area in Europe (Deliblato Sands Nature Reserve), and we transplanted two replicates of each clone to a polluted highway site with a heavy traffic flow. After a period of acclimatization, lower levels of photosynthetic pigment concentrations and higher stomatal density and specific leaf area in transplants verified that the chosen highway site was indeed more stressful and therefore suitable for estimation of the flower asymmetry biomonitoring potential. We analyzed radially and bilaterally symmetrical flower structures (radial fluctuating asymmetry (RA) and bilateral fluctuating asymmetry (FA)) on three perianth parts—falls, standards, and styles—and calculated various asymmetry indices based on linear and geometric morphometrics. Despite utilizing a heavily polluted environment and fairly large sample sizes, only one asymmetry index was significantly higher on the polluted site with demonstrated stressful effects on utilized plants, indicating that flower asymmetry was not an efficient method for biomonitoring in the case of I. pumila RA and FA indices.