The physiological and biochemical responses of pedunculate oaks (
L.) to heat stress (HS) and mycorrhization (individually as well in combination) were estimated. One-year-old
seedlings were grown ...under controlled conditions in a pot experiment, inoculated with a commercial inoculum of ectomycorrhizal (ECM) fungi, and subjected to 72 h of heat stress (40 °C/30 °C day/night temperature, relative humidity 80%, photoperiod 16/8 h) in a climate chamber, and they were compared with seedlings that were grown at room temperature (RT). An in-depth analysis of certain well-known stress-related metrics such as proline, total phenolics, FRAP, ABTS, non-protein thiols, and lipid peroxidation revealed that mycorrhized oak seedlings were more resistant to heat stress (HS) than non-mycorrhized oaks. Additionally, levels of specific polyamines, total phenolics, flavonoids, and condensed tannins as well as osmotica (proline and glycine betaine) content were measured and compared between four treatments: plants inoculated with ectomycorrhizal fungi exposed to heat stress (ECM-HS) and those grown only at RT (ECM-RT) versus non-mycorrhized controls exposed to heat stress (NM-HS) and those grown only at room temperature (NM-RT). In ectomycorrhiza inoculated oak seedlings, heat stress led to not only a rise in proline, total phenols, FRAP, ABTS, non-protein thiols, and lipid peroxidation but a notable decrease in glycine betaine and flavonoids. Amounts of three main polyamines (putrescine, spermine, and spermidine) were quantified by using high-performance liquid chromatography coupled with fluorescent detection (HPLC/FLD) after derivatization with dansyl-chloride. Heat stress significantly increased putrescine levels in non-mycorrhized oak seedlings but had no effect on spermidine or spermine levels, whereas heat stress significantly increased all inspected polyamine levels in oak seedlings inoculated with ectomycorrhizal inoculum. Spermidine (SPD) and spermine (SPM) contents were significantly higher in ECM-inoculated plants during heat stress (approximately 940 and 630 nmol g
DW, respectively), whereas these compounds were present in smaller amounts in non-mycorrhized oak seedlings (between 510 and 550 nmol g
DW for Spd and between 350 and 450 nmol g
DW for Spm). These findings supported the priming and biofertilizer roles of ectomycorrhizal fungi in the mitigation of heat stress in pedunculate oaks by modification of polyamines, phenolics, and osmotica content.
The paper examines hydromorphic soils from the class of gley soils, soil type humogley. The examined soils are located in the protected part of the inundation of the middle course of the Danube. ...According to the chemical properties of the examined soils, the pH value ranges from 7,64 to 8,15 on average, and with depth there is an increase in alkalinity. The total salts of the examined soils had increased values in the humus horizon and ranged from 0,06 to 0,09%. The texture classes of the humus horizon of these soils are: clay loam to sandy clay loam, while the lower sub-horizons of the gley are textural classes of sandy loam, loamy sand and sand. The influence of the Danube water level on the groundwater level results in high correlation coefficients, which range from 0,67 to 0,88. The groundwater in these soils had the highest level from 28 cm to 70 cm depth, and the lowest level was from 110 to 175 cm deep. The amplitude of groundwater variation during the year in the examined humogley soils ranges from 66 to 132 cm. Groundwater quality classes according to U.S. Salinity Laboratories are unfavorable and range from C3S1 to C4S1, ie salt to very salty water with low sodium content, and according to the FAO classification the water quality is such that there is a moderate need for restriction. High groundwater level above the critical level, as well as watering the soil with water of this quality can have an impact on salinization of the surface horizon of humogley soil of the examined area.
Pedunculate oak is among the most economically important deciduous forest tree species in Europe and is also a host for many important ectomycorrhizal (ECM) fungi. The aim of this study was to ...analyse the ECM fungal community in a mature pedunculate oak stand near Morović, Serbia in spring and autumn. ECM fungi were determined by combining morpho-anatomical characterization of ectomycorrhizas with molecular analysis based on PCR amplification of the internal transcribed spacer region of fungal nuclear ribosomal DNA. The number of ECM fungal taxa and the number of different categories of fine roots were counted, diversity indices were calculated, and ECM fungi were classified into exploration types. Twenty-one ECM fungal taxa were recorded in the studied mature pedunculate oak stand, 19 in spring and 13 in autumn. ECM communities consisted of one dominant taxon and a larger number of rare taxa. Lactarius quietus was the most abundant ECM fungus in both seasons which made association with more than half of ECM root tips. At the stand near Morović, contact exploration type (ET) dominated, short-distance ET was less abundant, while medium-distance fringe ET and long-distance ET were rare in both seasons. The most pronounced difference between seasons is recorded in the number of ECM fungal taxa. The number of ECM fungal taxa and diversity indices recorded in the studied pedunculate oak stand were lower or similar compared to values obtained in stands of oak species across Europe.
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.
The paper presents the hydrological characteristics of the humogley soil in the area of Čelarevo and Kovilj marsh. The granulometric composition and dynamics of groundwater in these soils in relation ...to the Danube water level were examined during two years of monitoring. The granulometric composition and the distance from the Danube riverbed are of great importance for the hydrological properties of these hydromorphic soils. The studied soils are characterized by a heavier granulometric composition in a powerful surface humus horizon, where the texture classes are sandy clay loam to clay loam. The lower parts are subhorizonts of gley, with lighter mechanical composition, and textural classes: sandy loam, loamy sand and sand. The highest relative groundwater level for these soils ranged from 44 to 70 cm in the first year and from 72 to 90 cm in the second year of monitoring. The lowest relative groundwater level ranged from 110 cm to 175 cm for the first year of monitoring, while in the second year it ranged from 154 to 224 cm. Amplitude of groundwater variance ranged from 66 to 132 cm and 82 to 134 cm depending on the year of monitoring. The influence of the Danube water level on the variation of groundwater level is evident. During the first year of monitoring, the water level was extremely high, and the effect on the groundwater level was correlated from 0.67 to 0.88. In the second year of monitoring lower water level was recorded which showed a lower impact on groundwater level with a correlation of 0.12 to 0.39. Considering the distance from 1632 to 1916 m from the Danube watercourse, a significant influence of higher water level on the groundwater level of the studied soils is observed, while at lower water level this influence is much smaller.
This study evaluates in vitro tolerance of white poplar genotypes to the presence of lead in an acidic rooting medium. Lead was supplemented in form of Pb(NO3)2, in the following concentrations: 0 M ...(Control), 10-6 M, 10-5 M, 10-4 M and 10-3 M. After four weeks of cultivation, the following characters were measured: number of roots, the length of the longest root, the shoot height, dry root mass and dry shoot mass, and parameters related to photosynthetic pigments: content of chlorophyll a, b, a+b, and of carotenoids in fresh mass, as well as chlorophyll a/b ratio. For further statistical analysis, tolerance indices by Turner and Marshal (TI) were calculated for each measured character. The strongest inhibitory effect was achieved on the medium with 10-4 M Pb(NO3)2, but the best differentiation between genotypes was achieved on the medium with 10-5 M Pb(NO3)2. The highest tolerance indices for the length of the longest root and shoot height had genotypes L-12 and LBM, and for root and shoot dry mass genotypes LCM and L-12. There were no significant differences between genotypes in tolerance indices by any of the examined photosynthetic parameters. The obtained results suggest that both low pH and the presence of citric acid as chelating agent improved evaluation of lead tolerance in comparison with the results obtained on media with standard pH and without citric acid in similar studies. In vitro tests on acidic medium with citric acid can efficiently differentiate examined genotypes for lead tolerance, which could be important for their use in phytoextraction projects, especially on acidic soils.
Although sessile oak is one of the most important deciduous forest tree species in Europe, data on the diversity of ectomycorrhizal (ECM) fungi on sessile oaks in the Republic of Serbia are scarce. ...The aim of this study was to provide the first insight into the diversity of ECM fungi on sessile oak in Serbia. Two sites Info center and Brankovac, located in National Park Fruška gora were chosen. ECM fungi were identified combining morphological and anatomical characterization with molecular analysis of nuclear rDNA internal transcribed spacer (ITS) region. All vital ECM root tips were counted, diversity indices were calculated, and ECM fungi were classified into the exploration types. The granulometric and chemical composition of soil were analyzed as well. At both sites, 26 different ECM fungal taxa were recorded in total, 17 taxa were observed at the site Info center and 12 taxa at Brankovac. ECM communities consisted of a few abundant taxa and a larger number of rare taxa.
Lactarius quietus, Cenococcum geophilum,
and
Tomentella sublilacina
were recorded at both sites. High abundance of contact and short-distance exploration types recorded in studied stands suggests that soils are sufficiently rich in total nitrogen and organic matter. Values of diversity indices recorded in studied sessile oak stands from Fruška gora were lower in comparison to those obtained in stands of different oak species across Europe which is likely induced by drought. To get a more thorough insight into the diversity of ECM fungi on sessile oak, research should be continued at more sites and seasonal dynamics should be included.
Hrast kitnjak je jedna od ekonomski i ekološki najvažnijih vrsta listopadnog šumskog drveća u Europi. U većini ekosustava umjerene klimatske zone zasnivanje, rast i preživljavanje stabala ovise o njihovoj zajednici sa ektomikoriznim (ECM) gljivama. Pri tome informacije o strukturi ECM zajednice mogu pružiti dragocjene informacije o funkcioniranju šumskih ekosustava. Međutim, podaci o raznolikosti
ECM gljiva na hrastovima u Republici Srbiji su rijetki. Cilj ovog istraživanja bio je pružiti prvi uvid u raznolikost ECM gljiva na hrastu
kitnjaku u Srbiji. Odabrane su dvije lokacije Info centar i Brankovac, smještene u Nacionalnom parku Fruška gora. ECM gljive su identificirane kombiniranjem morfološke i anatomske karakterizacije s molekularnom analizom nuklearne rDNA ITS regije. Prebrojani su svi vitalni ECM korijenski vrhovi, izračunati indeksi raznolikosti i ECM gljive su klasificirane u eksploracijske tipove. Analiziran je i granulometrijski i
kemijski sastav tla. Na obje lokacije zabilježeno je ukupno 26 taksona ECM gljiva, 17 taksona zabilježeno je na lokaciji Info centar i 12 taksona na Brankovcu. ECM zajednice sastojale su se od nekoliko brojnih ECM gljiva i većeg broja rijetkih ECM gljiva. Na obje lokacije zabilježeni su
Lactarius quietus
,
Cenococcum geophilum
i
Tomentella sublilacina
.
Na lokaciji Info centar dominirale su porodice Thelephoraceae, Russulaceae i Inocybaceae, dok su na lokaciji Brankovac najzastupljenije
familije bile Entolomataceae, Tuberaceae i Russulaceae. Velika brojnost
kontaktnih i eksploracijskih tipova kratkih udaljenosti zabilježena u proučavanim sastojinama sugerira da su tla dovoljno bogata ukupnim dušikom i organskim tvarima. Vrijednosti indeksa raznolikosti zabilježene u proučavanim sastojinama hrasta kitnjaka s Fruške gore bile
su niže u usporedbi s onima dobivenim u sastojinama različitih vrsta hrasta diljem Europe, što je vjerojatno uzrokovano sušom. Da bi se dobio
temeljitiji uvid u raznolikost tipova ektomikoriza na hrastu kitnjaku, trebalo bi nastaviti s istraživanjima na više mjesta i uključiti sezonsku dinamiku.
Pedunculate oak (
Quercus robur
L.) is economically and ecologically one of the most important tree species in lowland forests of Southeastern Europe, and it is endangered by numerous biotic and ...abiotic factors. In this study, we investigated the effect of drought and herbivore attack of gypsy moth (
Lymantria dispar
L.) on two families of young oak seedlings subjected to the following treatments: drought (D); gypsy moth (GM); both drought and gypsy moth (D+GM) and control (Ø) for a period of 15 days followed by a 7-day recovery period. During both treatment and recovery, physiological parameters - net photosynthesis (A), transpiration (E), stomatal conductance (gs), sub-stomatal CO2 concentration (Ci), water use efficiency (WUE), nitrate reductase activity (NRA) and chlorophyll content (Chl) were measured. Our results showed significant effects of stress factors on physiological processes in oak seedlings which could have potential impact on forest regeneration. Also, differences in the reaction between investigated families indicated the need for breeding and selection of more resistant progenies and provenances of pedunculate oak.
Hrast lužnjak (
Quercus robur
L.) predstavlja jednu od ekonomski i
ekološki najznačajnijih drvenastih vrsta u jugoistočnoj Europi, čiji je
opstanak znakovito ugrožen promjenama okoliša koje se najčešće očituju u
poremećaju vodnog režima i napadima kukaca. Imajući u vidu činjenicu da
oba negativna čimbenika dovode do poremećaja fizioloških procesa u biljkama i da često utječu na biljke zajedno, cilj ovoga pokusa bio je ispitati utjecaj pojedinačnog i zajedničkog djelovanja suše i napada kukaca na fiziologiju hrasta lužnjaka i mogućnost različite reakcije uvjetovane porijeklom sadnica.
U ovom smo radu ispitivali utjecaj suše i napada gubara (
Lymantria dispar
)
na klijance hrasta lužnjaka porijeklom iz dvije familije polusrodnika koji su bili naklijani u kontroliranim uvjetima i potom izloženi sljedećim tretmanima: suša ( D); gubar (GM); suša i gubar (D+GM) te kontrola (Ø) u trajanju od 15 dana, nakon čega je slijedio oporavak biljaka u trajanju od 7 dana. Krajem tretmana i nakon oporavka, izvršena
su mjerenja fizioloških parametara – stopa neto fotosinteze (A), stopa transpiracije (E), stopa provodljivosti puči (gs), intercelularna koncentracija CO2 (Ci), učinkovitosti korištenja vode (WUE), aktivnosti nitrat-reduktaze (NRA) i sadržaja klorofila.
Rezultati mjerenja fizioloških parametara prilikom induciranog Kod tretiranih klijanaca A opala je za 42-61% u odnosu na kontrolni tretman (Graf 1) a u isto vrijeme, zabilježen je porast Ci u svim tretmanima, što ukazuje na metaboličku limitiranost fotosinteze, osobito ako se uzme u obzir da nije zabilježeno signifikantno smanjenje provodljivosti puči u svim tretmanima. Inducirani stres je različito utjecao na aktivnost nitrat-reduktaze koja je bila smanjena samo kod familije 2 u svim tretmanima. Period oporavka biljaka (Graf 2) nije doveo do povećanja intenziteta fotosinteze kod ispitivanih sijanaca hrastova u obje familije, ali je zabilježena razlika u pogledu razine njene limitiranosti. Kod familije 2 limitiranost je bila uvjetovana zatvorenošću puči (smanjena vrijednost gs), dok je kod familije 7 ona i dalje bila metaboličke prirode (visoke vrijednosti Ci). Oporavak je uvjetovao povećanje razine aktivnosti nitrat-reduktaze, što ukazuje na postepeni oporavak biljaka.
Analiza varijance utjecaja tretmana, familije i perioda oporavka (Tablica 1) pokazala je znakoviti utjecaj porijekla sjemena na sve ispitivane parametre osim intenziteta neto fotosinteze (p>0.001), dok je utjecaj tretmana bio signifikantan kod svih ispitivanih parametara (p>0.001) Period oporavka je imao signifikantan utjecaj (p<0.001) samo za E, NRA i WUE.
Dobiveni su rezultati pokazali značajan utjecaj stresa na fiziološke procese u klijancima hrasta lužnjaka, posebice na intenzitet neto fotosinteze, dok
je oporavak pokazao različitu reakciju ispitivanih familija unatoč i dalje smanjenom intenzitetu neto fotosinteze. Dobiveni rezultati ukazuju
i na značaj porijekla sjemena, odnosno utjecaj njegove genetske pozadine na reakciju ispitivanih familija glede njihove reakcije i oporavka od stresa. To ukazuje na mogućnost korištenja fizioloških parametara u procesu selekcije reproduktivnog materijala hrasta lužnjaka
na otpornost prema stresnim čimbenicima poput suše ili napada defolijatora.
The ongoing climate change have multi-faceted effects not only on metabolism of plants, but also on the soil properties and mycorrhizal fungal community. Under climate change the stability of the ...entire forest ecosystems and the carbon balance depend to a large degree on the interactions between trees and mycorrhizal fungi. The main drivers of climate change are CO2 enrichment, temperature rise, altered precipitation patterns, increased N deposition, soil acidification and pollutants, ecosystem fragmentation and habitat loss, and biotic invasion. These drivers can impact mycorrhizal community directly and indirectly. We discussed the influence of each driver on mycorrhizal community and outlined how mycorrhizas play an important role in the resilience and recovery of forest ecosystems under climate change, by mitigating detrimental effects of CO2 enrichment, temperature rise, drought, lack of nutrients, soil acidification, pollutants, pests, and diseases. Conservation of the overall biodiversity in forest ecosystems as well as providing the most favourable conditions for the development of mycorrhizae can contribute to increasing the resilience of forest ecosystems to climate change.
Klimatske promjene koje su u tijeku, imaju višestruke učinke ne samo na metabolizam biljaka, već utječu i na svojstva tla i zajednicu mikoriznih gljiva. Pod utjecajem klimatskih promjena, stabilnost cjelokupnog šumskog ekosustava i ravnoteža ugljika ovise u velikoj meri o interakciji između drveća i mikoriznih gljiva. Pokretači klimatskih promjena su porast razine CO2, porast temperature, promjene distribucije oborina, povećano taloženje dušika, zakiseljavanje tla i zagađivanje polutantima, fragmentacija ekosustava, gubitak staništa i širenje invazivnih organizama. Pokretači klimatskih promjena mogu izravno i neizravno utjecati na zajednicu mikoriznih gljiva. U radu je dan prikaz utjecaja svakog od navedenih pokretača na mikoriznu zajednicu i naglašeno da mikorize imaju važnu ulogu u otpornosti i oporavku šumskih ekosustava ublažavanjem štetnih učinaka porasta CO2, porasta temperature, suše, nedostatka hranjivih sastojaka, zakiseljavanja tla, porasta zagađivača u tlu, štetočina i bolesti. Očuvanje cjelokupne biološke raznolikosti u šumskim ekosustavima kao i osiguranje što povoljnijih uvjeta za razvoj mikorize može doprinijeti povećanju otpornosti šumskih ekosustava na klimatske promjene.
In this work, tolerance of five genotypes of white poplar (Populus alba L.)
on five concentrations of sodium chloride (1 mM, 3 mM, 10 mM, 33mM and 100
mM) in rooting medium was examined, based on 20 ...parameters that included
biomass, photosynthetic and biochemical parameters. Concentration of 100 mM
NaCl was inhibitory for biomass accumulation, content of photosynthetic
pigments, total flavonoids content, total phenolics, increment of radical
scavenging ability against ABTS+and DPPH+radicals, the increment of sodium
content, the decrement of potassium and magnesium content, and the increment
of potassium/sodium ratio in shoots of examined white poplar genotypes. This
and medium with 33 mM could be purposed for further research on salt
tolerance in white poplar. It could be concluded that genotype L-80 is the
most tolerant against salinity, and that examined parameters can be
indicative for the selection of white poplar genotypes tolerant to salinity.
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