Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

Ecophysıologıcal Investıgatıons In Metal Stressed Populus Tremula L.

(Tremelous Poplar) X Populus Alba L. (Whıte Poplar) 717-1b4
The forest ecosystem is of particular importance from an economic and ecological perspective. However, the stress physiology of trees, perennial and woody plants, is far from being fully understood. Cadmium is a heavy metal toxic for humans, animals and plants. It is a widespread trace pollutant with a long biological half-life.
Cadmium (Cd) heavy metal enters agricultural soils mainly from industrial processes, phosphate fertilizers and atmospheric deposition, and then it could be transferred to the food chain. The ability of Populus to absorb and accumulate significant quantities of heavy metals in aerial parts offers the possibility to use them for removing pollutants from their substrate. However, scarcely any studies have attempted to describe the profile of metal distribution among the tree organs and the wood tissues.
For that purpose, Populus tremula x Populus alba (genotype INRA 717-1B4) was exposed to two consecutives Cd concentrations (3.2 mmoles and 16mmoles Cd ) in order to better understand the cumulative effects Cd. During the treatment, the total leaf area and the diameter of the cuttings (radial growth) were measured. The net photosynthetic rate and the leaf stomatal conductance to water vapour were also measured on the last fully expanded leaf. At the end of the two stress time courses, we have determined the ion distribution in the different organs (roots, leaves and wood tissues) of young trees by ICP-OES and evaluated their effects on tree metabolism.
According to the results of our analysis, plant water contents and leaf numbers have not shown any change in both Cd application period. In the second application period, we have determined decreases in dry weights and stomatal conductance, stunted growth, chlorosis, necrosis, inhibition in photosynthesis and radial growth. No change was observed in the first period. In both periods, plant lengths and the area of ​​leaves ranged differently. For the distribution of ions in each period, Cd accumulation showed higher accumulation in roots. According to these results, we think that Populus might be a good candidate for phytoremediation, especially for phytostabilization.

 

AYAN Hakan

Tez Adı : Büyükçekmece Gölü’ndeki Bazı Ağır Metallerin Astacus leptodactylus (Eschscholtz, 1823)’ta Mevsimsel Olarak İzlenmesi

Danışman : Yrd. Doç. Dr. Simten Nerdin KUBANÇ

Anabilim Dalı : Biyoloji

Programı : Zooloji

Mezuniyet Yılı : 2013

Tez Savunma Jürisi : Yrd. Doç. Dr. Simten Nerdin KUBANÇ

Prof. Dr. Melike ERKAN

Doç. Dr. Nuray BALKIS

Prof. Dr. Mustafa TEMEL

Doç. Dr. Figen Esin KAYHAN