Uticaj povećanih koncentracija Zn na klijanje semena i rast sejanaca Ailanthus altissima (Mill.) Swingle

Abstract

Neki teški metali, kao što je cink, su esencijalni mikronutrijenti neophodni biljkama za obavljanje važnih fizioloških procesa. Međutim, povećane koncentracije cinka mogu imati negativne efekte na rast i razvoj biljaka i prouzrokovati pojavu simptoma toksikacije. Zbog toga je vrlo važno ispitati koje drvenaste vrste su tolerantne na povećane koncentracije cinka i koje se odlikuju sposobnošću preživljavanja na zemljištima kontamiranim teškim metalima U radu je ispitivan efekat povećanih koncentracija cinka na klijanje semena i razvoj klijavaca invazivne drvenaste vrste Ailanthus altisima (Swingle) Mill. radi boljeg razumevanja adaptivnih sposobnosti ove vrste na stres od teških metala i mogućnosti korišćenja u fitoremedijaciji. Semena vrste Ailanthus altissima tretirana su cink sulfatom u koncentracijama 25, 100 i 250 μM. Nakon klijanja, klijavci su premešteni u komoru za gajenje u hidrokulturu gde je cink sulfat dodat u koncetracijama od 100, 250 i 500 μM. Dobijeni rezultati ukazuju da tretmani cinkom, uključujući i najveću koncentraciju, nisu u potpunosti inhibirali klijanje semena iako je došlo do smanjenja pokazatelja klijanja. Analizirajući dužinu hipokotila i korenka, utvrđeno je da ne postoji značajna statistička razlika između različitih tretmana. U daljem gajenju u hidroponskom eksperimentu, cink je inhibirao razviće listova i korena. Analizirani kvantitativni parametri klijanja i morfometrija klijavaca A. altissima pokazuju tolerantnost na povećane koncentracije cinka, u ovim najranijim fazama razvića, dok se u fazi formiranja prvih listova uočava inhibitorni efekat većih koncentracija.

Some heavy metals such as Zn are essential micronutrients for plants. However, in a high concentration in soils they could cause repression of growth with toxicity symptoms. It is therefore very important to investigate the species that are tolerant to high concentration of zinc which have the ability to survive on soils contaminated with heavy metals. This paper presents an investigation of the effect of elevated Zn concentrations on the germination and seedling growth of the invasive tree species Ailanthus altissima (Swingle) Mill., aimed at a better understanding of its adaptation ability to heavy metal stress and potential use in phytoremediation. Seeds of Ailanthus altissima were treated with Zn concentrations of 25, 100 and 250 μM in form of zinc sulfate. After germination, the seedlings at the stage of first leaf development were transferred into a growing chamber in the hydroponic system where zinc sulfate was added in the concentrations of 100, 250 and 500 μM. The results showed that Zn treatments, including the highest concentration, have caused a reduction in seed germination parameters. Considering the hypocotyl and radicle length, there was no significant statistical difference among the treatments, but further growth of young seedlings in hydroponics under high concentrations of Zn, cause an inhibition of the root system growth and repress development of assimilating organs. Seeds and seedlings of A. altissima are tolerant to elevated Zn concentrations at early stages of development. However, later on with leaves development, the inhibitory effect of the strongest concentrations is expressed.