Hiperakumulacija kadmija pri različnih populacijah ranega mošnjaka v Slovenijiin pomen za fitoremediacijo

Povzetek

Ključne besede

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Jezik:	Slovenski jezik
Leto izida:	2012
Izvor:	Ljubljana
Tipologija:	2.11 - Diplomsko delo
Organizacija:	UL PEF - Pedagoška fakulteta
Založnik:	[N. Kavčič]
UDK:	631.453:546.48(043.2)
COBISS:	9600073
Št. ogledov:	1161
Št. prenosov:	313
Ocena:	0 (0 glasov)
Metapodatki:

Ostali podatki

Sekundarni jezik:	Angleški jezik
Sekundarni naslov:	Hyperaccumulation of cadmium in different populations of pennycress (Thlaspi praecox) and its significance for phytoremediation
Sekundarni povzetek:	The aim of our study was to compare three different populations of pennycress Thlaspi praecox (populations from Lozice, Lokovec and Mežica) when exposed to different concentrations of cadmium (Cd) in the substrate. Thlaspi praecox is indigenous to Slovenia and it has been recently discovered to hyperaccumulate Cd. In the first part of our experiments we have grown three different populations of Thlaspi praecox under greenhouse conditions. These populations were grown in substrates with different levels of Cd (0, 50, 100, 250 mg/kg Cd). We have collected the plants from substrate before the flowering period. We separated the substrate from the roots and divided the pants to shoots and roots. Plant material was washed thoroughly and freeze dried. The roots and shoots were mineralized with mixture of HNO3 and HClO4 (10:1) and we extracted the Cd from the substrate with the ammonium acetate (NH4Ac). The concentration of Cd in roots, shoots and substrate was measured by atomic absorption spectrometry (AAS). In the second part of our experiments we have collected Thlaspi praecox plant in their natural habitats (Lozice, Lokovec, Mežica) in the time of flowering and seeding. We separated the substrate from the roots and divided the pants to shoots and roots. The measurements of concentration of Cd in roots, shoots and substrate were performed by X-ray fluorescence spectrometry (XRF). The results showed that there is a difference in concentration of Cd in roots, shoots and substrates among populations collected in the natural habitats. The population from Mežica has the highest concentration of Cd in all the samples and is statistically different from Lozice and Lokovec populations. The populations from Lokovec and Ložice have TF higher than 1 while TF of Mežica population is below 1. The BAF of shoots is the highest in Mežica and Lokovec populations while BAF of roots is the highest only in Mežica population. The results from natural habitats showed that population from Lozice exceed the warning value of Cd concentration while populations from Mežica and Lokovec exceed the critical value of Cd concentration in soil. Populations from Lokovec and Mežica in their natural habitats exceed the limit which represents the Cd hyperaccumulation capability (>100 mg Cd/kg v DW). The results of our laboratory population show that the populations do not differ statistically in their biomass. By increasing Cd concentration in the substrate the biomass of roots declined in all populations. The population from Mežica has the highest Cd concentration in roots and shoots, the highest BAF and the highest total content of Cd in roots and shoots. The Mežica population has also the best phytoextraction potential however its TF is smaller than 1, which is uncommon for this population. The results showed that all populations have abilitiy to hyperaccumulate Cd because Cd concentrations in roots and shoots exceeded100 mg/kg of Cd, when Cd was added to the substrate. All populations also tolerated the highest concentration of Cd in the substrate. Based on these results we can confirm that the population of Thlaspi praecox from Mežica is best suited for phytoextraction from Cd contaminated soil.
Sekundarne ključne besede:	biology;biologija;
Vrsta datoteke:	application/pdf
Vrsta dela (COBISS):	Diplomsko delo
Komentar na gradivo:	Univ. Ljubljana, Pedagoška fak., Biotehniška fak., Biologija in gospodinjstvo
Strani:	X, 72 f.
Vrsta dela (ePrints):	thesis
Naslov (ePrints):	Hyperaccumulation of cadmium in different populations of pennycress (Thlaspi praecox) and its significance for phytoremediation
Ključne besede (ePrints):	koncentracija Cd
Ključne besede (ePrints, sekundarni jezik):	Cd concentration
Povzetek (ePrints):	V diplomski nalogi smo želeli primerjati različne populacije (Lozice, Lokovec, Mežica) ranega mošnjaka (Thlaspi praecox) pri različnih koncentracijah Cd v substratu. Rani mošnjak je nedavno odkrita vrsta, ki hiperakumulira Cd, in je v Sloveniji avtohtona. V rastnih komorah smo pri kontroliranih pogojih iz semen vzgojili tri različne populacije Thlaspi praecox - Lozice, Lokovec in Mežica. Rastline so rasle na različnih koncentracijah Cd v rastnem substratu (0, 50, 100, 250 mg/kg Cd). Rastline smo vzorčili pred cvetenjem, tako da smo ločili rastni substrat, korenine in poganjke. Korenine in poganjke smo mineralizirali z mešanico HNO3 in HClO4 (v razmerju 10:1). Cd v rastnem substratu pa smo ekstrahirali z amonijevim acetetom. Koncentracijo Cd v koreninah, poganjkih in substratu smo nato izmerili z atomsko absorpcijsko spektroskopijo (AAS). V drugem delu poskusov pa smo v času cvetenja in semenenja nabrali rastline na njihovih naravnih rastiščih (Lozice, Lokovec, Mežica) in določili koncentracijo Cd v koreninah, poganjkih in tleh s pomočjo rentgensko fluorescenčne spektrometrije (XRF). Populacije, ki so zrasle na svojih naravnih rastiščih, se med seboj razlikujejo v koncentraciji Cd v tleh, poganjkih in koreninah, s tem, da ima mežiška populacija največjo koncentracijo Cd v vseh vzorcih in se statistično značilno razlikuje od ostalih dveh populacij. Lokovška in loziška populacija imata TF večji od 1, medtem ko ima mežiška populacija TF manjši od 1. BAF poganjkov je največji pri mežiški in lokovški populaciji. BAF korenin pa je največji le pri mežiški populaciji. Rezultati iz narave kažejo, da koncentracija Cd v tleh pri populaciji iz Lozic preseže opozorilno vrednost za Cd (2 mg kg-1), populaciji iz Lokovca in Mežice pa presežeta kritično vrednost za Cd (12 mg kg-1). Lokovška in mežiška populacija že na svojih naravnih rastiščih presežeta mejo, ki določa hiperakumulacijsko sposobnost za Cd (>100 mg Cd/kg v SM). Populacije, ki smo jih vzgojili pri kontroliranih pogojih, se po biomasi med seboj statistično značilno ne razlikujejo. S povečevanjem koncentracije Cd v tleh pa je opaziti upad biomase korenin pri vseh populacijah še posebej pri lokovški in loziški populaciji. Mežiška populacija ima največjo koncentracijo Cd v poganjkih in koreninah, največji BAF, največjo skupno vsebnost Cd v poganjkih in koreninah in največjo fitoekstrakcijsko sposobnost. TF pa ima manjši od 1, kar pa ni običajno za mežiško populacijo. Pri vseh populacijah smo izmerili več kot 100 mg/kg Cd v SM v poganjkih in koreninah (tam kjer smo dodali Cd v substrat). Prav tako so vse populacije tolerirale visoke koncentracije Cd v substratu. Glede na rezultate smo potrdili, da je mežiška populacije najbolj primerna za fitoremediacijo s Cd onesnaženih tal.
Povzetek (ePrints, sekundarni jezik):	The aim of our study was to compare three different populations of pennycress Thlaspi praecox (populations from Lozice, Lokovec and Mežica) when exposed to different concentrations of cadmium (Cd) in the substrate. Thlaspi praecox is indigenous to Slovenia and it has been recently discovered to hyperaccumulate Cd. In the first part of our experiments we have grown three different populations of Thlaspi praecox under greenhouse conditions. These populations were grown in substrates with different levels of Cd (0, 50, 100, 250 mg/kg Cd). We have collected the plants from substrate before the flowering period. We separated the substrate from the roots and divided the pants to shoots and roots. Plant material was washed thoroughly and freeze dried. The roots and shoots were mineralized with mixture of HNO3 and HClO4 (10:1) and we extracted the Cd from the substrate with the ammonium acetate (NH4Ac). The concentration of Cd in roots, shoots and substrate was measured by atomic absorption spectrometry (AAS). In the second part of our experiments we have collected Thlaspi praecox plant in their natural habitats (Lozice, Lokovec, Mežica) in the time of flowering and seeding. We separated the substrate from the roots and divided the pants to shoots and roots. The measurements of concentration of Cd in roots, shoots and substrate were performed by X-ray fluorescence spectrometry (XRF). The results showed that there is a difference in concentration of Cd in roots, shoots and substrates among populations collected in the natural habitats. The population from Mežica has the highest concentration of Cd in all the samples and is statistically different from Lozice and Lokovec populations. The populations from Lokovec and Ložice have TF higher than 1 while TF of Mežica population is below 1. The BAF of shoots is the highest in Mežica and Lokovec populations while BAF of roots is the highest only in Mežica population. The results from natural habitats showed that population from Lozice exceed the warning value of Cd concentration while populations from Mežica and Lokovec exceed the critical value of Cd concentration in soil. Populations from Lokovec and Mežica in their natural habitats exceed the limit which represents the Cd hyperaccumulation capability (>100 mg Cd/kg v DW). The results of our laboratory population show that the populations do not differ statistically in their biomass. By increasing Cd concentration in the substrate the biomass of roots declined in all populations. The population from Mežica has the highest Cd concentration in roots and shoots, the highest BAF and the highest total content of Cd in roots and shoots. The Mežica population has also the best phytoextraction potential however its TF is smaller than 1, which is uncommon for this population. The results showed that all populations have abilitiy to hyperaccumulate Cd because Cd concentrations in roots and shoots exceeded100 mg/kg of Cd, when Cd was added to the substrate. All populations also tolerated the highest concentration of Cd in the substrate. Based on these results we can confirm that the population of Thlaspi praecox from Mežica is best suited for phytoextraction from Cd contaminated soil.
Ključne besede (ePrints, sekundarni jezik):	Cd concentration
ID:	8311321