Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Physiological aspects of resistance of common oak (Quercus robur L.), the Turkey oak (Quercus cerris L.) and black poplar (Populus nigra L.) under conditions of water deficit

Fiziološki aspekti otpornosti hrasta lužnjaka (Quercus robur L.), cera (Quercus cerris L.) i crne topole (Populus nigra L.) u uslovima vodnog deficita

Auteur : Topić Mirjana

Université de soutenance : University of Novi Sad,

Grade : Doctor of Philosophy (PhD) 2015

Résumé
The impact of water deficit and recovery on physiological features of the black poplar clones, as well as of the oaks populations were analyzed. The aim of this research was to indicate the potential of the studied genotypes for survival under changing environmental conditions, in accordance with current climate changes, which include the reduction in amount of rainfall and limited water availability. Obtained results have shown a specific variation of studied morpho-anatomical, physiological and biochemical parameters which depended on soil humidity on the applied treatment (control, drought followed by recovery and permanent drought), as well as on plant genotype.

Water deficit on permanent drought treatment had little negative effect on plant growth of poplar clone X/32, as well as oak populations L1 and C1. Plant height stress tolerance index also confirmed good morphological adaptation to drought of these genotypes. Stomatal index was not negatively affected by water deficit in oak plants. In both experiments, a permanent drought treatment led to the largest reduction in the values of gas exchange parameters in almost all genotypes.

On the other hand, concentration of photosynthetic pigments was not considerably decreased in plants exposed to water deficit, as well as the parameter Fv/Fm, in most examined plants. Compared to the control, the impact of permanent drought treatment on biochemical parameters was expected, in the most cases. Compared to the control, proline content in leaves of most examined genotypes was significantly increased on permanent drought treatment, while nitrate reductase activity was significantly decreased.

Examined genotypes exhibiting slight or no reduction in values of the most examined parameters during severe drought stress, could be used for afforestation in arid sites. Arid habitats appeared to be more numerous due to the effects of global climate changes.

Mots Clés : black poplar clones, populations of pedunculate oak and the Turkey oak, water deficit, ecovery, soil humidity, morpho-anatomical, physiologicaland biochemical parameters, tolerance to water deficit

Présentation et version intégrale (DART)