Danijela Miljkovic

Fluctuating asymmetry in Robinia pseudoacacia leaves—possible in situ biomarker?

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.

Provenance plasticity of European beech leaf traits under differing environmental conditions at two Serbian common garden sites

Climate change will affect European beech (Fagus sylvatica L.) ecosystems negatively due to well-known vulnerability of this species to drought. Phenotypic plasticity has been recognized as the primary means in rapid acclimation to adverse environmental conditions. Provenance trials of forest tree species represent a valuable tool for assessing provenance adaptive potential to changing environments. In the present study, we examined the adaptive response capability (plasticity) of certain leaf anatomical traits in different European beech provenances to contrasting environmental conditions prevailing in two provenance trials. While one location of the trials is an isolated, marginal site, the other is a site within the original geographic range of beech forests in Serbia. The study involved 12 provenances originating from Austria, Bosnia and Herzegovina, Croatia, Germany, Hungary, Romania and Serbia. The results of the study evidenced that genetic differences of the provenances are mainly responsible for the differences in leaf traits. Cluster analysis showed absence of association between provenances from the same geographic regions (e.g., Germany and Balkan Peninsula, respectively), revealing phenotypic heterogeneity between them. Steep reaction norms, observed for anatomical traits studied, indicate the possibility of plastic provenance response to changes in environmental conditions. The highest values of plasticity index, observed for stomatal density and thicknesses of palisade and spongy parenchyma, seem to be the result of a regulative function of stomata and mesophyll structure on physiological adaptation to the unfavorable growth conditions at the marginal site. Such sclerophyllous leaf structures, indicating drought resistance, were observed in certain provenances from Central/Eastern Europe and mesic sites, indicating that beech provenances from warmer sites in Southern Europe may not necessarily be the only source of drought-resistant ecotypes.

Provenance by site interaction and stability analysis of European beech (Fagus sylvatica L.) provenances grown in common garden experiments

Abstract Fifteen provenances of European beech (Fagus sylvatica L.) were evaluated for stability and adaptability by height growth at four test sites in Bosnia and Herzegovina (1), Croatia (1) and Serbia (2). Provenance trials were established in spring 2007 by planting 2- and 3-yearold seedlings and arranged in a randomized complete block design. The data from seven 6- year-old and eight 5-year-old provenances were obtained in 2009 and analyzed separately. Finlay and Wilkinson’s regression analysis and Additive main effects and multiplicative interaction model (AMMI model) were used to assess provenance by site interaction (P × S) and to identify beech provenances that have high and stable performance in different environments, at the juvenile stage of development. Analysis of variance showed that effects of provenance, site, and P×S interaction are highly significant (p<0.001) in both age groups. Linear regression model evidenced that most of the provenances had regression coefficients not significantly different from unity (b=1.0), except for provenances Sjeverni Dilj Caglinski (HR24) and Vranica-Bistrica (BA59). The partitioning of the total sum of squares (SS) exhibited that the site effect was the predominant source of variation in both age groups of provenances (50.7% and 38.5%, respectively). Additionally, regression analysis explained 15.8% and 33.2% of provenance by site interaction terms, in provenances age six and five years, respectively, while the AMMI analysis accounted for 62.2% and 78.7% in P×S interaction. The results of AMMI showed that the first principal component (PC1) was statistically significant in both age groups. Adaptability and stability of provenances to the test sites were estimated with AMMI1 and AMMI2 biplots. Provenance Sjeverni Dilj Caglinski (HR24) showed constant performance over tested sites, characterizing with aboveaverage height growth at low yielding environments. Provenances HR25 and BA61 showed the opposite type of adaptation, being adapted to high yielding sites. Provenance Valkonya (HU42) was characterized by IPCA1 score close to zero and above average mean height growth, suggesting general adaptation to the tested environments. The implication of P×S was discussed in light of impact of climate change on beech and selection of most suitable provenances for future reforestation programs.

Ontogeny of flower parts on naturally growing Iris pumila clones: Implications for population differentiation and phenotypic plasticity studies

Previous studies revealed significant phenotypic plasticity, genetic variability and population differentiation of flower morphometric traits on dwarf bearded iris Iris pumila. Also, study of I. pumila flowering phenology revealed significant impact of habitat type as well as population differentiation for flowering time. Since the flowering time can influence other flower traits, we performed this analysis of flower morphometric traits in three time points during the flower bud ontogenic development in two habitat types (open vs. shaded). Analysis revealed that for most of the traits greater trait values were recorded for open habitat but only on latter time points. For most of the analyzed traits direction of differences in bud stage was the opposite to the direction of differences in mature flower stage detected in previous studies. However, length of the stem, a trait that showed the greatest variability between habitats and populations and therefore greatest genetic differentiation and phenotypic plasticity, was significantly greater in the samples from the late flowering shaded habitat in all time samples, indicating that in case of this trait different mechanisms were involved. Those findings have implications for design of the future studies on I. pumila.

Ontogenetic plasticity of anatomical and ecophysiological traits and their correlations in Iris pumila plants grown in contrasting light conditions

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.

Morphological variability of Quercus robur L. leaf in Serbia

Batos B., D. Miljković, M. Perović, S. Orlović (2017): Morphological variability of Quercus robur L. leaf in Serbia.Genetika Vol 49, No2, 529 541. This paper presents the results of a study dealing with leaf morphological variability of Quercus robur L. 148 trees were sampled from 5 population across Serbia and 17 morphological traits were assessed. Interpopulation variability was confirmed by the results of the analysis of variance (ANOVA). A statistically significant (p <0.05) effect of population was obtained for most of the studied morphological characters. Intrapopulation variability was confirmed by statistically significant tree effects for all of the studied leaf characters (all p < 0.05). The results of the multivariate analysis of variance (MANOVA) confirmed a significant population and tree share in the total phenotypic variability (all p <0.05). By applying the canonical discriminant analysis (CDA), the first discriminant function accounted for 63% of the variability between populations and the second accounted for 20% of the population variability. The leaf area (AREA), specific leaf area (SLA) and surface area to perimeter ratio (ARPE) had the greatest effect on population differentiation (CDA). It is assumed that different environmental conditions affect population differentiation and that high intrapopulation variability is due to intraspecific variability.

Leaf stomatal traits variation within and among black poplar native populations in Serbia

Populus nigra as a keystone riparian pioneer tree species is one of the rarest and most endangered species in Europe due to the loss of its natural habitats. Genetic diversity existence is a key factor in survival of one species, and stomata as genetically controlled trait could be used for differentiation studies. With the aim of proving stomatal phenotypic variation of the four native populations of Populus nigra located on the banks of three biggest river valleys (Dunabe, Tisa and Sava) in the region of Vojvodina in northern Serbia, we examined various leaf stomatal traits (stomatal length and width, pore length and width, stomatal density, shape coefficient and stomatal and pore area). We tested the differences of stomatal traits among populations, interindividual variability - differences among trees, the intraindividual variability, the differences between sun-exposed and shaded leaves, among leaves nested in exposition and the differences in adaxial and abaxial leaf surface. Based on mixed model ANOVA results, interpopulation variability, as statistically significant differences, observed only for stomatal pore length and shape, while all examined traits showed interindividual variability. On the intraindividual level the results showed differences for stomatal traits, except for stomatal width, stomatal shape coefficient and stomatal density regarding leaf exposure. For better understanding of how morphological and stomatal characteristics vary in black poplar populations, further studies should be necessary involving controlled environmental conditions with the aim of examining phenotypic plasticity to changing climate conditions.

Population and individual variability of the leafing phenophase of pedunculate oak in three successive years.

The leafing phenophase of pedunculate oak (Quercus robur L.) was analyzed at two locations in Belgrade (Ada Ciganlija - “AC”, Bojcinska suma - “BS”). The observations were made on 29 trees per site for three consecutive years (2004, 2005, 2006). In the “BS” site the phenophase of leafing starts and ends earlier than in the “AC” site. The largest number of trees in the “AC” site are classified in the late phenological group and in the “BS” site they belong to the “average” group. Population variability of the analyzed parameters of the phenophase of leafing was confirmed by the results of a Mann - Witney U - test for each year of observation, except for the end of the second year of observation and start of leafing in the first year of observation. According to the results of an F - test significant differences between sites were confirmed for all analyzed parameters except for the duration of leafing (2005) and the start of leafing (2006). Differences among the years of observation in the “AC” site were significant only in the end and in the “BS” site for they were significant for all three growth stages of scrolling. Despite the different environmental conditions in the three years of monitoring the stability of the phenology of analyzed populations was maintained (the percentage of trees that were always over the years of observation in the same phenological group relative to the start of leafing „AC” - 41.3%, „BS” - 55.2%), which is primarily the result of the genetic structure of populations and intraspecies variability. [Projekat Ministarstva nauke Republike Srbije, br. 43007 III: Istraživanje klimatskih promena i njihovog uticaja na životnu sredinu - pracenje uticaja, adaptacija i ublažavanje]