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SummaryAlthough being present much widely in terms of its geographical distribution, pedunculate oak (Quercus robur L.) represents one of the crucial species in forest ecosystems in South Eastern Europe. We wanted to contribute to existing efforts in designing genetic monitoring methodology for this noble broadleaved species, through the screening of genotypes with different health status and belonging to two phenological varieties [early (var. praecox) vs late (var. tardissima)] using seven oxidative stress parameters (total protein content, total phenolic compounds content, total flavonoids content, DPPH, ABTS, NO radical scavenger activities and Ferric reducing antioxidant power essay - FRAP). Results of this study provided significant biological message, contributing to better understanding of existing biodiversity of pedunculate oak in Serbia. Four out of seven oxidative stress screening tests (total phenolic compounds content, total flavonoids content, RSC NO and FRAP) clearly discriminated late vs early individuals sampled from selected pedunculate oak gene pool. Although presented results did not show significancy in using mentioned parameters to distinct damaged from vital individuals, nevertheless, knowledge gained through discussion and comparison with previous studies contributed to precise determination of biochemical tests which might be used in future efforts of genetic monitoring of this species., SažetakPrema klimatskim scenarijima RCP-a, hrast lužnjak (Q. robur L.) označen je kao najteže pogođena vrsta drveća zbog stalnih, intenzivnih klimatskih promjena. Propadanje hrastovih šuma može uzrokovati velike ekonomske gubitke, budući da se hrastovi smatraju vrlo vrijednim primjercima drveća zbog duge povijesti iskorištavanja za proizvodnju drva i gradnju (Mikac i sur., 2018.). Uzimajući u obzir da uobičajeni biokemijski parametri mogu doprinijeti razumijevanju temeljnih obrambenih mehanizama biljaka protiv stresa od suše i stoga se koristiti kao pouzdani deskriptori prilagodljivosti u kontekstu klimatskih promjena, cilj ove studije bio je utvrditi postoji li neki od 7 predloženih testova praćenja oksidacijskog stresa (ukupni sadržaji bjelančevina, fenola, flavonoida i testovi hvatači slobodnih radikala – ABTS, NO, FRAP i DPPH) koji može poslužiti za dugoročni genetski monitoring dviju sorti hrasta lužnjaka (rani vs kasni). Fenološki varijeteti [rani (var. praecox) vs kasni (var. tardissima)] i fiziološka skupina (vitalne ili oštećene) bile su promatrane varijable u testiranih jedinki zbirnog radnog hrasta vitalnog (PEOV), zbirnog ranog hrasta oštećenog (PEOD), zbirnog kasnog vitalnog (PLOV) i zbirnog ranog oštećenog (PLOD). Svaka objedinjena (zbirna) skupina sadržavala je ukupno 10 ili 11 uzoraka, mjerenih u tri primjerka kako bi se postigla optimalna statistička značajnost za svaku skupinu (za više, pogledajte pododjeljak Statistika). Sakupljeno lišće odmah je označeno i stavljeno u aluminijski folij, konzervirano na suhom ledu i transportirano u Laboratorij za kemijske i biokemijske analize Instituta za nizinsko šumarstvo i okoliš (ILFE) na daljnju obradu. Dva grama hrastovog lišća homogenizirano je u ohlađenom mužaru s tučkom s 10 ml fosfatnog pufera (0,1 M KH2PO4, pH=7), centrifugirano 10 min na 11000 okretaja u minuti i supernatant je korišten za daljnji test praćenja oksidativnog stresa (Tablica 1), prema uputama autora. Sve analize određene su spektrofoto

Although being present much widely in terms of its geographical distribution, pedunculate oak (Quercus robur L.) represents one of the crucial species in forest ecosystems in South Eastern Europe. We wanted to contribute to existing efforts in designing genetic monitoring methodology for this noble broadleaved species, through the screening of genotypes with different health status and belonging to two phenological varieties [early (var. praecox) vs late (var. tardissima)] using seven oxidative stress parameters (total protein content, total phenolic compounds content, total flavonoids content, DPPH, ABTS, NO radical scavenger activities and Ferric reducing antioxidant power essay - FRAP). Results of this study provided significant biological message, contributing to better understanding of existing biodiversity of pedunculate oak in Serbia. Four out of seven oxidative stress screening tests (total phenolic compounds content, total flavonoids content, RSC NO and FRAP) clearly discriminated late vs early individuals sampled from selected pedunculate oak gene pool. Although presented results did not show significancy in using mentioned parameters to distinct damaged from vital individuals, nevertheless, knowledge gained through discussion and comparison with previous studies contributed to precise determination of biochemical tests which might be used in future efforts of genetic monitoring of this species., Prema klimatskim scenarijima RCP-a, hrast lužnjak (Q. robur L.) označen je kao najteže pogođena vrsta drveća zbog stalnih, intenzivnih klimatskih promjena. Propadanje hrastovih šuma može uzrokovati velike ekonomske gubitke, budući da se hrastovi smatraju vrlo vrijednim primjercima drveća zbog duge povijesti iskorištavanja za proizvodnju drva i gradnju (Mikac i sur., 2018.). Uzimajući u obzir da uobičajeni biokemijski parametri mogu doprinijeti razumijevanju temeljnih obrambenih mehanizama biljaka protiv stresa od suše i stoga se koristiti kao pouzdani deskriptori prilagodljivosti u kontekstu klimatskih promjena, cilj ove studije bio je utvrditi postoji li neki od 7 predloženih testova praćenja oksidacijskog stresa (ukupni sadržaji bjelančevina, fenola, flavonoida i testovi hvatači slobodnih radikala – ABTS, NO, FRAP i DPPH) koji može poslužiti za dugoročni genetski monitoring dviju sorti hrasta lužnjaka (rani vs kasni). Fenološki varijeteti [rani (var. praecox) vs kasni (var. tardissima)] i fiziološka skupina (vitalne ili oštećene) bile su promatrane varijable u testiranih jedinki zbirnog radnog hrasta vitalnog (PEOV), zbirnog ranog hrasta oštećenog (PEOD), zbirnog kasnog vitalnog (PLOV) i zbirnog ranog oštećenog (PLOD). Svaka objedinjena (zbirna) skupina sadržavala je ukupno 10 ili 11 uzoraka, mjerenih u tri primjerka kako bi se postigla optimalna statistička značajnost za svaku skupinu (za više, pogledajte pododjeljak Statistika). Sakupljeno lišće odmah je označeno i stavljeno u aluminijski folij, konzervirano na suhom ledu i transportirano u Laboratorij za kemijske i biokemijske analize Instituta za nizinsko šumarstvo i okoliš (ILFE) na daljnju obradu. Dva grama hrastovog lišća homogenizirano je u ohlađenom mužaru s tučkom s 10 ml fosfatnog pufera (0,1 M KH2PO4, pH=7), centrifugirano 10 min na 11000 okretaja u minuti i supernatant je korišten za daljnji test praćenja oksidativnog stresa (Tablica 1), prema uputama autora. Sve analize određene su spektrofotometrijs

In light of climate change, pedunculate oak (Q. robur L.) was marked as the most threatened European tree species. Pedunculate oak is particularly jeopardized by powdery mildew disease caused by Erysiphe alphitoides. We hypothesized that priming of this tree species with ectomycorrhizal fungi could mitigate biotic stress and produce bioprotective properties against the disease. In this study, we have compared oaks’ foliar physiological and biochemical responses upon infection with E. alphitoides in the presence and absence of ectomycorrhizal fungi (ECM). The main aim of this study was to inspect how ECM modulate an oak’s biochemical response to infection with E. alphitoides, particularly at the level of the accumulation of the main polyamines (putrescine, spermidine, and spermine), soluble osmolytes (proline and glycine betaine), and phenolics (total phenolic content, flavonoids, and condensed tannins). A polyamine quantification was performed after derivatization by using high-performance liquid chromatography (HLPC) coupled with fluorescent detection. Oak seedlings inoculated with ECM fungi exhibited significantly higher levels of putrescine, spermine, and proline compared to non-inoculated seedlings, indicating the priming properties of the ECM. E. alphitoides caused an increase in individual and total polyamine content and lipid peroxidation in oak leaves regardless of the effect of ECM, while causing a decrease in physiological and antioxidative parameters and water use efficiency (WUE). Common biochemical parameters may contribute to understanding the underpinning plant defense mechanisms in three-way interactions among plants and pathogenic and ectomycorrhizal fungi and can be used as reliable adaptability descriptors in the context of climate change.

This study quantified the physical and mechanical properties of sycamore maple (Acer pseudoplatanus L.) as a basis for assessing wood quality. The physical properties of oven-dry density, density at 12% MC, green density, basic density, longitudinal, radial, tangential and volumetric shrinkages were tested and the mechanical properties of bending strength, modulus of elasticity at bending, compression strength parallel to grain and compression strength in radial and tangential direction as well as of Brinell hardness on the cross, radial, and tangential section were determined. Five sycamore maple trees from Medvednica region were selected for the purposes of this research. The results were compared with known literature data on sycamore maple wood, beech wood from the same sight, and beech wood from Gorski Kotar region. For a better understanding of sycamore maple physiology, as well as for assessing the quality of wood products, the distribution of wood properties within the tree radius, from pith to bark, was investigated. There was a general bell shaped distribution, in the radial direction, in wood density, and mechanical properties of sycamore maple wood. Shrinkages decreased from pith to bark, except for tangential shrinkage with bell shaped pattern. All investigated wood densities of sycamore maple from Medvednica were similar to the findings of studies known in literature, as well as shrinkages, except for the lower longitudinal shrinkage. Investigated mechanical properties of sycamore maple wood were similar to the findings of studies known in literature, except for the lower bending strength and modulus of elasticity (MOE). Investigated sycamore maple indicated better dimensional stability than beech wood from two locations in the region, although it did not match the beech wood regarding mechanical properties, especially wood hardness.

In the present study we compared the physiological performances of Prunus avium L., Robinia pseudoacacia L., Juglans nigra L., and Populus x euramericana cl. Pannonia, planted at the coal mine tailings of the Mining Basin "Kolubara" (Serbia), to assess the potential of different tree species for land reclamation. The measurements were conducted during three consecutive years characterized by contrasting climatic conditions (wet and drought). The results showed that the rate of net photosynthesis (A), stomatal conductance (gs) and transpiration rate (E) sharply declined in two dry years in all tree species. These trends were particularly evident for R. pseudoacacia and J. nigra, in which A, gs and E were twice as low during the dry years. On the other hand, R. pseudoacacia and P. x euramericana cl. Pannonia seedlings were characterized by the highest water-use efficiency and intrinsic water-use efficiency during the dry years, indicating that these species are more efficient responders to drought, due to their ability to maintain a balance between the loss of water and the CO2 assimilation rates. The survival rate of the examined tree species was high ( GT 86%) and increased in the following order: P. avium LT J. nigra LT R. pseudoacacia LT P. x euramericana cl. Pannonia. Based on the obtained results we recommend R. pseudoacacia and P. x euramericana cl. Pannonia as a good solution for afforestation and revitalization of degraded habitats, such as coal mine tailings, although high survival rate, observed in P. avium and J. nigra, makes these two species a candidate for planting during degraded sites reclamation, as well.

Aim of study: In the present paper the nature and level of co-dependence between leaf functional traits and intrinsic water-use efficiency (WUEi) were studied in one-year-old Quercus robur L. seedlings, grown in a common garden experiment under moderate drought conditions. The study was established to identify those traits that might potentially be utilized to improve leaf-level WUEi, and therefore be used in breeding programmes to enhance drought adaptation of Q. robur.Area of study: The study was carried out at the common garden site within the UNESCO Biosphere Reserve Mura-Drava-Danube.Material and methods: The study involved one-year-old seedlings of eight half-sib lines of Q. robur. Eighteen leaf parameters were analyzed; i.e. physiological, biochemical, morphological and anatomical. The data were processed using multivariate statistical methods: a) principal component analysis, b) stepwise regression analysis, and c) path coefficient analysis.Main results: The results showed that leaf stomata traits, particularly stomatal density (SD), and leaf dry mass per unit leaf area (LMA) were the most important traits, closely associated with WUEi. Stomatal density achieved the highest score on PC1 (0.825), in which WUEi had the highest loading (0.920), as well. SD was also included first in stepwise regression model.

The present study focuses on the estimation of the effects of oak powdery mildew on the leaf physiological traits of Quercus robur L., based on the combination of chlorophyll a fluorescence parameters with leaf gas exchange parameters. In order to have a better insight into the effects of Erysiphe alphitoides (Griffon and Maubl) U. Braun and S. Takam. on the light-harvesting apparatus, a greenhouse semi-controlled experiment was performed with 50 individuals of one-year-old seedlings. Half of them were kept under optimal conditions, and the other half were infected with the studied obligate leaf pathogen. The criteria for carrying out the measurements was a visual coverage of the leaf surface with epiphytic micelia above 75%. The results of the present study showed a highly significant decrease of net photosynthesis and an increase of substomatal CO. concentration of leaves infected with E. alphitoides above 75%. The net photosynthesis was reduced by 43.9%, meanwhile the 65.7%. increase of substomatal CO: concentration was even more substantial. Moreover, the effects of oak powdery mildew on all of the observed parameters of fast kinetics of chlorophyll a fluorescence were found to be statistically significant. However, the parameters of the pulse amplitude modulated fluorescence were just mildly affected by the examined pathogen, with only the minimal and maximal fluorescence values of previously dark adopted leaves showing a significant difference. The results of this study showed the effectiveness of chlorophyll a fluorescence parameters in detection of severe biotic stress conditions, on the example of highly infected oak leaves with E. alphitoides. Follow up studies should be conducted in order to determine the effects of oak powderily mildew in early and mild infection stages, based on the parameters of chlorophyll a fluorescence.