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UTICAJ PH VREDNOSTI NA USVAJANJE BAKRA KOD KRASTAVCA

INFLUENCE OF PH ON CUPPER UPTAKE IN CUCUMBER

Autor: Biljana AnĎelković, Farmaceutsko-fizioterapeutska škola 2. razred

Mentor: Dragana S. Nikolić, istraživač-saradnik, Institut za molekularnu genetiku i genetičko
inženjerstvo

Rezime:

Krastavac (Cucumis sativus L.) je uzgajan u hidroponičnoj kulturi na različitim pH vrednostima
(4,5; 5,5 i 6,5). S pojavom drugog lista, započet je tretman različitim koncentracijama bakra:
5µM (25x veća od kontrolne) i 10 µM (50x veća od kontrolne) u kombinaciji sa 3 pH vrednosti
(ukupno 9 grupa biljaka). Tokom tretmana praćen je porast dužine korena i količina hlorofila,
SPAD metrom. Nakon 6 dana tretmana, na polovini biljaka su analizirani morfološki parametri
stresa, a u drugoj polovini je odredjen stepen oksidativnog oštećenja merenjem nivoa lipidne
peroksidacije kod korena, starijeg i mlaĎeg lista. Rezultati su pokazali da je redukcija rasta
biljaka u korelaciji sa povećanjem prisutne koncentracije bakra. Lipidna peroksidacija je najviše
izražena kod mlaĎeg lista, jer taj list nije uspeo dovoljno da razvije antioksidativnu zaštitu. Biljke
gajene na pH 6,5 nisu imale karakteristične simptome usled viška bakra, dok su najviše patile
biljke gajene na pH 4,5. Zaključak je da se sa smanjenjem pH hranljivog rastvora, povećava
+
usvajanje bakra jer u rastvoru dominira redukovana forma bakra (Cu ) koju biljke jedino mogu
da usvoje.

Kljuĉne reĉi: krastavac, pH, koncentracija bakra, lipidna peroksidacija

Summary:

Cucumber (Cucumis sativus L.) was grown in hydroponic culture on different pH values (4,5; 5,5
i 6,5). With the emergence of the second leaf, treatment is initiated with different concentrations
of copper: 5 μM (25x higher than the control) and 10 μM (50x higher than the control) in
combination with the 3 different pH values (total of 9 groups of plants). During treatment the
length of the roots was measured, as well as chlorophyll content with SPAD meter. After 6 days
of treatment, half of the plants were used for morphological parameters measurements, and the
other half was used for determining the oxidative damage by measuring the level of lipid
peroxidation in roots, older and younger leaves. The results showed that a reduction in plant
growth is correlated with the increase of the copper concentration. Lipid peroxidation was most
pronounced in younger leaves, as this leaf had not been able to develop enough antioxidant
protection. Plants grown at pH 6.5 did not have the characteristic symptoms caused by excess
copper, whereas plants which suffered the most are the ones grown at pH 4.5. In a conclusion,
with a reduction of pH of nutrient medium, copper uptake increases due to predominant reduced
+
form (Cu ) in the solution, the only form that plants are able to uptake.
Key words: cucumber, pH, copper concentration, lipid peroxidation

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