scholarly journals Physiological responses of two pedunculate oak (Quercus robur L.) families to combined stress conditions – drought and herbivore attack

2020 ◽  
Vol 144 (11-12) ◽  
pp. 582-583
Author(s):  
Milan Drekić ◽  
Srđan Stojnić ◽  
Saša Orlović ◽  
Milan Borišev ◽  
Leopold Poljaković-Pajnik ◽  
...  
Keyword(s):  
Gypsy Moth ◽  
Quercus Robur ◽  
Reductase Activity ◽  
Abiotic Factors ◽  
Recovery Period ◽  
Net Photosynthesis ◽  
Stress Factors ◽  
Pedunculate Oak ◽  
Herbivore Attack ◽  
Oak Seedlings

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 (&Oslash;) 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 CO<sub>2</sub> 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.

Effect of Salt Stress on Growth and on the Detoxifying Pathway of Pedunculate Oak Seedlings (Quercus robur L.)

1995 ◽  
Vol 147 (1) ◽  
pp. 144-151 ◽  
Author(s):  
Laurence Sehmer ◽  
Badr Alaoui-Sosse ◽  
Pierre Dizengremel
Keyword(s):  
Salt Stress ◽  
Quercus Robur ◽  
Pedunculate Oak ◽  
Oak Seedlings

scholarly journals The most frequent powdery mildews on forest woody species and their impact

2005 ◽  
pp. 9-29 ◽  
Author(s):  
Dragan Karadzic ◽  
Tanja Milijasevic
Keyword(s):  
Powdery Mildew ◽  
Gypsy Moth ◽  
Natural Regeneration ◽  
Quercus Robur ◽  
Woody Species ◽  
Pedunculate Oak ◽  
Forest Trees ◽  
Fungus Species ◽  
Powdery Mildews ◽  
Oak Trees

The most frequent fungus species known as powdery mildews, causing the diseases of forest trees, were studied. Among forest woody species, oaks are especially susceptible to powdery mildew attack, and among them pedunculate oak (Quercus robur L) is highly endangered. This paper reports 49 species of powdery mildews. However, Microsphaera alphitoides has the greatest significance in forest economy, causing the decline of seedlings in nurseries and also aggravating the natural regeneration of pedunculate oak. This fungus, together with gypsy moth and honey fungus (Armillaria mellea) participates in the dying of old oak trees. Powdery mildews can be successfully controlled by fungicides, and sulphur fungicides Karatan and Rubigan are especially effective.

scholarly journals Host plant effect on the susceptibility of gypsy moth caterpillars to insecticides

2002 ◽  
pp. 69-78
Author(s):  
Slobodan Milanovic
Keyword(s):  
Host Plant ◽  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Abiotic Factors ◽  
Pedunculate Oak ◽  
Moth Population ◽  
Study Results ◽  
Turkey Oak ◽  
Host Plant Effect ◽  
Oak Leaves

Gypsy moth (Lymantria dispar L) is the most significant pest of broadleaf forests. The dynamics of gypsy moth population depends on several biotic and abiotic factors, but it is also highly dependent on the quality of consumed food. The gypsy moth control increasingly relies on the biological preparations based on Bacillus thuringiensis subspec. kurstaki (Btk) and Lymantria dispar Nuclear Poliedrosis virus (NPV). Chemical preparations are still applied although more rarely, the pyrethroids which include also lambda-cyhalothrin This paper presents the study results of the effect of host plant on gypsy moth caterpillar (Lymantria dispar L) susceptibility to lambda cihalotrine insecticide, by which the study oak leaves were contaminated. The study results show the lowest mortality of the caterpillars fed on contaminated leaves of Turkey oak (17.5%), then pedunculate oak (86.1%), and the highest mortality of caterpillars fed on sessile oak leaves (92%). The rate of the gypsy moth caterpillar development depends on the host plant Susceptibility of the gypsy moth caterpillars to the above preparation depends on the host plant The knowledge of the effect of host plant on insecticide efficiency in gypsy moth suppression would render insecticide utilisation optimal.

scholarly journals Antioxidative system response of pedunculate oak (Quercus robur L.) seedlings to Cd exposure

2019 ◽  
Vol 25 (6) ◽  
pp. 1377-1384 ◽  
Author(s):  
Magdalena Sozoniuk ◽  
Michał Nowak ◽  
Karolina Dudziak ◽  
Piotr Bulak ◽  
Justyna Leśniowska-Nowak ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Quercus Robur ◽  
Molecular Mechanisms ◽  
Antioxidative System ◽  
Metal Exposure ◽  
System Response ◽  
Pedunculate Oak ◽  
Cd Exposure ◽  
Regions Of Origin ◽  
Oak Seedlings

Abstract The use of pedunculate oak (Quercus robur L.), along with other tree species, for the afforestation of heavy metal contaminated lands is an attractive prospect. Little, however, is known of Q. robur tolerance and its antioxidative system response to heavy metal exposure. The main objective of the study was to determine the cadmium-induced changes in antioxidative system of pedunculate oak in an attempt to identify molecular mechanisms underlying Cd tolerance. This may be of great importance in respect of using Q. robur for phytoremediation purposes. As the response of the antioxidative system to heavy metal contamination can vary within species, the research was conducted on oak seedlings from two different regions of origin. Differences in antioxidative system response of seedlings derived from tested regions of origin were noticed both at the transcript and enzyme activity levels. The obtained results indicate that ascorbate peroxidase (APX; EC 1.11.1.11) and superoxide dismutase (SOD; EC 1.15.1.1) play a first barrier role in oak seedlings response to the oxidative stress caused by Cd exposure. Catalase (CAT; EC 1.11.1.6) is involved in reducing the negative effects of prolonged Cd treatment.

Growth and management of mixed Pinus sylvestris - Quercus robur stands in Flanders, Belgium

1993 ◽  
Vol 58 ◽  
Author(s):  
D. Maddelein ◽  
J. Neirynck ◽  
G. Sioen
Keyword(s):  
Pinus Sylvestris ◽  
Natural Regeneration ◽  
Quercus Robur ◽  
Good Growth ◽  
Pedunculate Oak ◽  
Selection System ◽  
Management Options ◽  
Stand Management ◽  
Pine Stands

Mature  Scots pine (Pinus sylvestris  L.) stands are dominating large parts of the Flemish forest area. Broadleaved  species regenerate spontaneously under this pine canopy. This study studied  the growth and development of two planted pine stands with an older natural  regeneration, dominated by pedunculate oak (Quercus  robur L.), and discussed management options for  similar stands.     The results indicated a rather good growth of the stands, with current  annual increments of 5 m3.ha-1.yr-1. The pine overstorey is growing into valuable sawwood  dimensions, while the broadleaved understorey slowly grows into the  upperstorey. The quality of the regeneration is moderate but can be improved  by silvicultural measurements (pruning, early selection).     In both stands, an interesting (timber production, nature conservation)  admixture of secondary tree species is present in the regeneration. Stand  management is evolving from the classical clearcut system towards a  combination of a type of selection and group selection system.

scholarly journals Effect of abiotic factors on sulfidogenic activity of bacteria Desulfuromonas sp.

2020 ◽  
Vol 11 (2) ◽  
pp. 170-174
Author(s):  
O. M. Сhaіka ◽  
T. B. Peretyatko
Keyword(s):  
Hydrogen Sulfide ◽  
Cell Density ◽  
Elemental Sulfur ◽  
Abiotic Factors ◽  
Electron Acceptors ◽  
Stress Factors ◽  
Sulfide Concentration ◽  
Sulfur Concentration ◽  
Reducing Bacteria ◽  
Hydrogen Sulfide Concentration

Sulfur-reducing bacteria are promising agents for the development of new methods of wastewater treatment with the removal of ions of heavy metals and organic compounds. Study of the effect of various environmental factors on the growth and sulfidogenic activity of sulfur-reducing bacteria allows one to investigate the adaptability of these microorganisms to stress factors. The paper deals with the effect of рН, different concentrations of elemental sulfur, hydrogen sulfide and presence of various electron acceptors on the growth and sulfidogenic activity of bacteria Desulfuromonas sp. YSDS-3. The calculation of C/S ratio for sulfur-reducing bacteria Desulfuromonas sp. YSDS-3 was made, with the comparison with similar parameters of sulfate-reducing bacteria. In the medium with elemental sulfur, concentration of hydrogen sulfide increased with the concentration of elemental sulfur. Bacteria Desulfuromonas sp. YSDS-3 accumulated their biomass in the most effective way at the concentration of elemental sulfur of 10–100 mM. In the medium with polysulfide form of sulfur at the neutral pH, bacteria produced hydrogen sulfide and accumulated biomass the best. Hydrogen sulfide at the concentration of 3 mM did not inhibit the bacterial growth, but further increase in the hydrogen sulfide concentration inhibited the growth of bacteria. The bacteria did not grow at the hydrogen sulfide concentration of 25 mM and above. As the concentration of elemental sulfur and cell density increases, sulfidogenic activity of the bacteria grows. Presence of two electron acceptors (S and K2Cr2O7, S and MnO2, S and Fe (III)) did not affect the accumulation of biomass of the bacteria Desulfuromonas sp. YSDS-3. However, under such conditions the bacteria accumulated 1.5–2.5 times less hydrogen sulfide than in the test medium. After 12–24 h of cultivation, different concentrations of elemental sulfur had a significant effect on the sulfidogenic activity. However, during 3–16 days of cultivation, the percentage of effect of elemental sulfur concentration decreased to 31%, while the percentage of effect of cell density increased threefold. Presence in the medium of the electron acceptors (Cr (VI), MnO2, Fe (III)) alternative to elemental sulfur led to a significant decrease in the content of hydrogen sulfide produced by sulfur-reducing bacteria.

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