Half-sib Lines of Pedunculate Oak (Quercus robur L.) Respond Differently to Drought through Biometrical, Anatomical and Physiological Traits

Quercus robur L. is one of the most valued tree species of deciduous temperate forests. However, in the last decade, serious oak declines and loss of adaptation plasticity have been reported throughout Europe as a consequence of drought. Therefore, the aim of the present study was to define the adaptation potential of five Q. robur half-sib lines from the UNESCO Biosphere Reserve Mura-Drava-Danube to drought, using physiological, anatomical and biometrical traits. Half-sib lines that exhibited drought tolerance had particular suites of trait expression regarding biometrical traits (seedling height, root length, root to shoot ratio of dry mass and specific leaf area), leaf stomatal traits (stomatal density per mm2, stomata guard cell length and width, stomatal aperture length and width) and leaf structural traits (adaxial epidermis thickness, palisade parenchyma thickness, spongy parenchyma thickness, lamina thickness). All of the observed parameters of chlorophyll a fluorescence were shown to be good indicators of short-term and severe drought. For the selection of drought-tolerant half-sib lines, all studied chlorophyll a fluorescence parameters associated with the heat dissipation of light energy (coefficient of non-photochemical quenching, quantum yield of regulated energy dissipation, Stern-Volmer type non-photochemical fluorescence quenching) and one parameter related to photochemical dissipation of light energy (effective quantum yield (efficiency) of PS II photochemistry) were proven to be suitable. On the other hand, the coefficient of photochemical quenching, coefficient of photochemical fluorescence quenching assuming interconnected photosystem II antennae and electron transport rate were not suitable for distinguishing the different responses of the studied half-sib lines under drought. The importance of results of the present study is in the selection of drought-tolerant Q. robur half-sib lines for future reforestation programs, particularly in protected areas with sensitive forest management and restricted activities for mitigation of the adverse effects of climate changes

Varijabilnost i diskriminacijska moć anatomskih parametara kod linija polusrodnika juglans regia podrijetlom iz prirodnih sastojina u Đerdapskoj klisuri, Srbija u rasadničkim uvjetima

This paper presents analysis of anatomical parameters of leaves in Juglans regia half-sib lines from natural stands in Đerdap Gorge in Serbia. Thirty-five half-sib lines were examined, designated according to the number of their mother trees from R1-R35. Twenty measured and derived anatomical parameters were examined, describing stomatal and leaf blade cross-section traits. According to Hierarchical analysis of variance, variation of the majority of characters describing stomatal properties were significantly affected by effect of half-sib lines. The effect of variation between plants within half-sib lines was significant for all examined stomatal traits. However, in cross-section characters, the effect of differences between half-sib lines was significant only for thickness of spongy mesophyll (SL). The discrimination model with seven selected traits achieved 60.5% of correct allocation, while the correct allocation of the model with all 20 examined traits was 81.6%. According to the results of stepwise discriminant analysis, the most powerful trait in discrimination of these half-sib lines were stomatal aperture width/stomatal aperture length ratio (Wb/La) and stomatal aperture length/ stomata guard cell length ratio (La/LA). Presented results strongly support implementation of stomatal and cross-section leaf traits in further studies that would deal with description of variability of Juglans regia.Domaći orah (Juglans regia L.) jednodoma je dugovječna vrsta značajna ponajprije zbog svojih jestivih plodova i tvrdog visokokvalitetnog drveta, ali i zbog široke primjene u ozelenjavanju urbanih područja, kao i u agrošumarsrtvu i uslugama ekosustava. Proučavanje varijabilnosti je vrlo značajno za očuvanje vrste i temelj za daljnju selekciju, očuvanje i poboljšanje germplazme. U radu su prikazani rezultati analize anatomskih parametara listova u linijama polusrodnika Juglans regia koji potječu iz prirodnih sastojina u Đerdapskoj klisuri u Srbiji. Domaći orah smatra se autohtonom vrstom na ovome području, i zastupljen je u mnogim fitocenozama poli i oligodominantnog tipa. Na pet lokaliteta odabrano je 35 majčinskih stabala, a iz njihovog sjemena su tijekom tri vegetacijske sezone u rasadničkim uvjetima uzgajane linije polusrodnika, označene prema brojevima majčinskih stabala od R1-R35. Ispitano je dvadeset izmjerenih i izvedenih parametara koji opisuju svojstva puči i poprečnog presjeka letka. Prema analizi varijacije poduzorka, varijacija većine osobina koje opisuju svojstva puči značajno je ovisila o učinku linija polusrodinika. Učinak varijacije biljaka unutar linija polusrodnika bio je značajan za sva ispitivana svojstva puči. Međutim, uz svojstva poprečnog presjeka plojke, učinak varijacije biljaka unutar linija polusrodnika bio je značajan samo za debljinu spužvastog tkiva (SL). Diskriminantni model sa sedam selektiranih svojstava ostvario je 60,5 % ispravne alokacije, dok je model sa svih 20 ispitanih svojstava postigao 81,6 % ispravne alokacije biljaka u odgovarajuće linije polusrodnika. Prema rezultatima kanoničke i stupnjevite diskriminantne analize, svojstva s najjačom snagom diskriminacije bili su omjer širine aperture puči/duljinu aperture puči (Wb/La) i omjera duljine aperture puči/duljine stanice zatvaračice (La/LA). Klasterska analiza je pokazala da se linije polusrodnika grupiraju u 5 klastera, među kojima dominiraju prvi (koji potječu uglavnom od majčinskih stabala na lokalitetima Štrbac i Zlatica) i drugi (koji potječu uglavnom od majčinskih stabala na lokalitetima Porečke šume i Bojana). Prikazani rezultati snažno podupiru primjenu parametara puči i poprečnog presjeka plojke u budućim studijama varijabilnosti Juglans regia

Emisije ugljikovog dioksida (CO2) iz tla tijekom obnove sastojine hrasta lužnjaka (Quercus robur L.) u ljetnom razdoblju

SummaryThe loss of soil organic carbon stock and increased CO2 emission from soil are induced by various human activities. The aim of this study was to examine whether an anthropogenic influence during the regeneration of a pedunculate oak (Quercus robur L.) stand can affect the increment of CO2 emission from the soil. The research was carried out within three plots, out of which two were exposed to different degrees of anthropogenic influence. The air samples were collected using the soil respiratory chambers and analysed using the gas chromatograph Agilent 8890. Based on the obtained results, soil temperature and moisture as the most dominant drivers of the CO2 emission had different effects on the CO2 flux from soil depending on the intensity of anthropogenic influences and environmental conditions. Within the experimental plot with the significant soil alteration, a reliable positive correlation was detected for the CO2 flux with the soil temperature (r = 0.77, p < 0.05). High significant correlation was observed considering soil moisture (r = 0.85, p < 0.05) in the natural soil where the application of pesticides was conducted. The results showed that both soils that were exposed to the anthropogenic influences had notably higher values of the CO2 flux in comparison to the reference natural soil without anthropogenic impacts.SažetakRad u šumarstvu razumijeva sve ljudske aktivnosti koje su prijeko potrebne za obavljanje planiranih šumarskih poslova, a radi ostvarivanja dobrobiti od šume i šumskoga zemljišta. U skladu s tim šumarski radnici, tj. ljudi s potrebnim znanjima, vještinama i sposobnostima, uz odgovarajuća sredstva za rad i predmet rada predstavljaju temeljni čimbenik šumarske proizvodnje. Stručno osposobljeni, odgovorni, savjesni i motivirani šumarski radnici imaju odlučujuću ulogu u ostvarivanju uspješnih proizvodnih i poslovnih rezultata te čine neodvojivu sastavnicu u suvremenoj, općeprihvaćenoj paradigmi održivoga gospodarenja šumama. Međutim, danas u svijetu stalnih promjena šumarstvo se neprestano nalazi pred izazovom osiguranja kvalificirane i održive radne snage. Nedostatak šumarskih radnika postaje sve učestaliji problem u europskom i svjetskom šumarstvu, a razlog tomu su različiti globalni demografski, ekonomski, tehnološki i politički procesi, kao i specifičnosti samog sektora. U radu se stoga, uz opće značajke šumarskog rada prikazuju neki pokazatelji stanja i položaja radne snage u šumarstvu Europe i svijeta. Posebno se obrađuju aktualna pitanja i problemi u regrutiranju potrebne šumarske radne snage (nedostatak radnika, manjak interesa kod mladih ljudi, starenje postojeće radne snage, šumarski poduzetnici, neformalno zapošljavanje i sl.) te određeni alati i instrumenti važni za uspješno privlačenje i zadržavanje šumarskih radnika (razumijevanje motivacije, kompenzacije za rad, obrazovanje i trening radnika, nove tehnologije i sl.). Svrha rada se sastoji u pružanju podloga koje mogu biti važan doprinos u unapređenju stanja i održivosti radne snage u šumarstvu

Heavy Metals Content in Foliar Litter and Branches of Quercus petraea (Matt.) Liebl. and Quercus robur L. Observed at Two ICP Forests Monitoring Plots

Background and Purpose: Due to the ability to uptake and accumulate heavy metals (HM) in their aboveground tissues, trees may be used for phytoremediation purposes, but also as bioindicators of environmental pollution. The aims of the present study were: a) to investigate the content and temporal variation of the studied HMs in different plant organs during the period of intensive leaf falling (September-October), in two species from genus Quercus; b) to evaluate the observed HMs content relative to plausible ranges of element concentration in foliar litter, as recommended by ICP Forests Foliar Co-ordinating Centre (IFFCC). Material and Methods: The contents of zinc (Zn), manganese (Mn), copper (Cu) and iron (Fe) were assessed in the litterfall (i.e. leaves and branches) of Quercus petraea (Matt.) Liebl. and Quercus robur L. grown at two ICP Forests Level II monitoring plots (Fruška Gora and Odžaci, Serbia). Plant material was sampled during September-October 2018 and analyzed by atomic absorption spectrophotometry. Results: Comparing the content of investigated HMs in foliar litter and branches of Q. robur and Q. petraea, notably higher concentrations of Mn and Fe have been observed in the foliage of both species, whereas Zn and Cu concentrations were higher in collected branch material of both of the above-mentioned tree species. The results further showed that, when compared to plausible ranges of element concentrations in foliar litter, given by ICP Forests Foliar Co-ordinating Centre (IFFCC), average concentrations of Fe and Zn in the leaves were within suggested limits, whereas certain concentrations of Mn and Cu exceeded the proposed ranges. Furthermore, the content of the studied HMs in plant material of both Quercus species significantly varied during sampling period. Conclusions: Although it was observed that concentrations of certain HMs were beyond plausible limits recommended by IFFCC, our results were in accordance with the findings of other authors who studied HMs content in Quercus species grown in natural forests. For that reason, these limits should be considered optionally, i.e. in the cases when the results significantly deviate from the suggested values. Moreover, we believe that the observed variation in the HMs content during sampling period is related to the sampling procedure commonly applied at ICP Forests monitoring plots, which is indirectly associated with the capacity of trees to accumulate HMs and their phenological properties

Diversity of Ectomycorrhizal Fungi in Young Pedunculate Oak Stand from Morović, Serbia

Although oaks belong to the economically most important hardwood tree species in Europe, data on the diversity of ectomycorrhizal (ECM) fungi on pedunculate oak in the Republic of Serbia are deficient. The aim of our study was to give the first insight into the diversity of ECM fungi in the young stand of pedunculate oak in Morović, Serbia. The combination of morpho-anatomical characterization and molecular analysis was used for determination of ECM fungi on penduculate oak. Studied parameters included: (i) counting of vital ECM root tips, (ii) calculation of diversity indices and (iii) classification of morphotypes of ectomycorrhizae into the exploration types. Eighteen ECM fungal taxa were recorded in the studied young pedunculate oak stand. Seven of them were identified to the level of species, eight fungi to the genus, two to the family level, and one ECM fungus remained unidentified. ECM communities consisted of a small number of abundant taxa and a bigger number of rare taxa. The most abundant ECM fungi were Entoloma sp., Thelephoraceae sp., Russula cf. odorata and Russula lilacea, which made association with the majority of ECM root tips. Short-distance exploration type (ET) dominated, followed by medium-distance smooth ET and contact ET, while long-distance ET and medium-distance fringe ET were rare at the Morović site. Values of diversity indices obtained in the studied pedunculate oak stand were comparable to the ones recorded in different oak stands over Europe. In order to get a deeper insight into the diversity of ECM fungi on pedunculate oak there is a need to continue research on increased number of sites and also to include seasonal dynamics

In vitro selection of drought-tolerant white poplar clones based on antioxidant activities and osmoprotectant content

IntroductionIn light of upcoming climate change, there is an urgent requirement for tree improvement regarding adaptability to drought-caused stress and the development of quick and reliable screening methodologies for genotypes’ drought tolerance. White poplar is, despite its high adaptability, considered to be an endangered tree species in Serbia, which gives it special importance in the preservation and improvement of biodiversity of riparian ecosystems. The main goal of this research was to evaluate the tolerance of five white poplar clones to the presence of polyethylene glycol (PEG 6000 molecular weight 6000) (different concentrations (e.g. 0 g/L, 1 g/L, 10 g/L, 20 g/L, and 50 g/L) in Aspen Culture Medium (ACM).MethodsThe tolerance of the clones was evaluated by using morphological parameters (shoot fresh and dry weight, root fresh and dry weight), photosynthetic pigments (contents of chlorophyll a, chlorophyll b, carotenoids, and chlorophyll a+b), and biochemical parameters (total phenolic content, total flavonoid content, ferric reducing antioxidant power, antioxidant activities (DPPH activity and ABTS assay), free proline content and glycine betaine content.Results and DiscussionThe values of morphological and photosynthetic pigments declined with an increase in the concentration of PEG 6000. At a concentration of 50 g/L, the content of shoot fresh mass decreased by 41%, the content of Chl a by 68%, Chl b by 65%, and Car by 76% compared to the control. Also, at the same medium, there was an increase in the content of total phenols, accumulation of proline, the content of glycine betaine as well as in antioxidant activity. Based on the obtained results, it can be assumed that more drought-tolerant clones are characterized by high values for biomass, high content of photosynthetic pigments, and high content of proline and glycine betaine in conditions similar to drought in vitro. Clone L-80 showed better results in most of the tested parameters, especially compared to the reference clone Villafranca

Genetic Diversity and Differentiation of Pedunculate Oak (Quercus robur L.) Populations at the Southern Margin of Its Distribution Range—Implications for Conservation

Understanding intraspecific genetic variation is one of the principal requirements for the evaluation of tree species capacity to cope with intensive climatic changes, as well as designing long-term conservation programs. Herein, we evaluated the genetic diversity and genetic structure of seven pedunculate oak (Quercus robur L.) populations, located at the southern margin of its distribution range on the Balkan Peninsula (Serbia). The objective of the study was to propose future in situ conservation measures aimed at protection of pedunculate oak adaptive and neutral genetic diversity at the species rear-edge. Genetic diversity and structure were estimated using twelve highly polymorphic simple sequence repeat (SSR) markers. The mean expected heterozygosity (He) was 0.769, allelic richness (AR) 9.63, and private allelic richness (pAR) 0.79, indicating high genetic diversity in the studied populations. Genetic differentiation among the populations was low (Fst = 0.032). Structure analysis, the unweighted pair group method with arithmetic mean (UPGMA) showed the existence of two gene pools unrelated to the populations’ area of occurrence. Taking into consideration the results of the current study and previous conservation activities on the pedunculate oak in Serbia, as well as the importance of rear-edge populations in the long-term conservation of the species genetic diversity, we suggested establishing three additional gene conservation units for securing long-term sustainability of the species

Proximity to riverbed influences physiological response of adult pedunculate oak trees

The pedunculate oak (Quercus robur L.) is economically and ecologically one of the most significant tree species in Serbia, however, little is known about the influence of the riverbed distance and its water supply on ecophysiological responses of this species. Given the limited information on the light-response curve of photosynthesis for oaks in southwest Srem, Serbia, the aim of this paper is to enhance understanding of their ecophysiological responses in this context. Maximum assimilation rate (Amax), the quantum yield (Ф), and light compensation point (LCP) were compared in adult trees situated along the transect from the river: (1) close to the river, (2) intermediate, (3) farthest from the river, and (4) forest reserve (second closest), with the first three transects being managed forests and the last one being an unmanaged forest reserve. The measurements were conducted in July during the first evidence of drought. The highest Amax rates were measured in all light intensities on the site closest to the river and the smallest on the site that was most distant to the water source. The most efficient were trees close to the river and the ones in the forest reserve. No significant difference between compensation points was confirmed for the studied groups of trees, although the forest reserve trees showed slightly higher values. The results demonstrated clear response between transects, which followed the distance from the riverbed. Pedunculate oak\u27s reliance on groundwater is in tight relation with ecophysiological processes in treesgroundwater depletion may threaten its survival in areas distant from the river

Psychosexual outcomes in women of reproductive age at more than two-years from excisional cervical treatment – a cross-sectional study

Purpose: To investigate the long-term psychosexual outcomes in women following excisional cervical treatment. Materials and methods: Women with cold-knife conization (CKC) or large loop excision of the transformation zone (LLETZ) treatment were interviewed after a follow-up colposcopy visit. Their demographics, treatment and psychosexual characteristics were recorded. Results: One hundred and forty six women with a mean age of 35.2 ± 5.4 years underwent either LLETZ (68.5%) or CKC (31.5%) treatment within 4.7 ± 2.7 years (range: 2–15) before the interview. 27.4% of women were less interested in sexual intercourse following treatment in comparison with their interest before. Those women with less interest in sexual intercourse after treatment had higher anxiety and depression scores and were more worried about disease progression. Women with post-treatment complications were at risk of less interest in sexual intercourse and of greater anxiety and depression. Women with abnormal smears at follow-up were at risk of greater anxiety. The type of treatment and grade of dysplasia did not affect their interest in sexual intercourse or the anxiety and depression scores. Conclusions: Approximately, one-third of women at more than two years post-treatment may suffer from less interest in sexual intercourse, have relatively greater anxiety and depression, and might still be concerned about the possibility of disease progression

Table_1_In vitro selection of drought-tolerant white poplar clones based on antioxidant activities and osmoprotectant content.xlsx

IntroductionIn light of upcoming climate change, there is an urgent requirement for tree improvement regarding adaptability to drought-caused stress and the development of quick and reliable screening methodologies for genotypes’ drought tolerance. White poplar is, despite its high adaptability, considered to be an endangered tree species in Serbia, which gives it special importance in the preservation and improvement of biodiversity of riparian ecosystems. The main goal of this research was to evaluate the tolerance of five white poplar clones to the presence of polyethylene glycol (PEG 6000 molecular weight 6000) (different concentrations (e.g. 0 g/L, 1 g/L, 10 g/L, 20 g/L, and 50 g/L) in Aspen Culture Medium (ACM).MethodsThe tolerance of the clones was evaluated by using morphological parameters (shoot fresh and dry weight, root fresh and dry weight), photosynthetic pigments (contents of chlorophyll a, chlorophyll b, carotenoids, and chlorophyll a+b), and biochemical parameters (total phenolic content, total flavonoid content, ferric reducing antioxidant power, antioxidant activities (DPPH activity and ABTS assay), free proline content and glycine betaine content.Results and DiscussionThe values of morphological and photosynthetic pigments declined with an increase in the concentration of PEG 6000. At a concentration of 50 g/L, the content of shoot fresh mass decreased by 41%, the content of Chl a by 68%, Chl b by 65%, and Car by 76% compared to the control. Also, at the same medium, there was an increase in the content of total phenols, accumulation of proline, the content of glycine betaine as well as in antioxidant activity. Based on the obtained results, it can be assumed that more drought-tolerant clones are characterized by high values for biomass, high content of photosynthetic pigments, and high content of proline and glycine betaine in conditions similar to drought in vitro. Clone L-80 showed better results in most of the tested parameters, especially compared to the reference clone Villafranca.</p