Uticaj genotipa i lokaliteta na dinamiku akumulacije teških metala u vegetativnim organima pšenice

Abstract

U cilju proučavanja uticaja kontaminacije vazduha i zemlje na dinamiku usvajanja i nakupljanja teških metala u korenovima i stablima pšenice postavljeni su i izvedeni poljski ogledi 2009. i 2010. godine na četiri lokaliteta. Ogledna polja bila su različito udaljena od Rafinerije Pančevo. Prvo polje se nalazilo u Vojlovici (udaljenost 200 m), drugo u PK Stari Tamiš (5 km) i treće u PDS Tamiš, na dve njive, sa redovnom upotrebom hemijskih sredstava u agrotehnici i njiva na kojoj ona nisu primenjivana 20 godina. Ovo polje bilo je udaljeno od Rafinerije 10 km. Predmet istraživanja bila su četiri genotipa ozime pšenice: Ljiljana, Pobeda, Renesansa i Apach. Uzorci biljnog materijala (korenovi i nadzemna vegetativna biomasa) uzimani su u fenofazama bokorenja, vlatanja i klasanja. Paralelno sa poljskim postavljeni su i ogledi u sudovima. Za punjenje sudova upotrebljena je zemlja sa oglednih polja koja je prethodno kontaminirana teškim metalima cinkom, olovom, hromom, bakrom i kadmijumom. Korišćena su sledeća jedinjenja: C4H6O4Pbx3H2O, CuSO4, Cd(NO3)2x4H2O, CrO3 i Zn(CH3COO)2x2H2O. Ona su primenjena u sledećim koncentracijama: 0 ppm, 50 ppm, 100 ppm, 250 ppm, 500 ppm i 1000 ppm. U sudove su posejana dva genotipa pšenice Pobeda i Ljiljana, a ogledi su postavljeni u stakleniku Poljoprivrednog fakulteta u Zemunu. Uzorci za ispitivanje teških metala u korenovima i stablima uzimani su u fazama bokorenja i vlatanja biljaka. Teški metali su (Zn, Pb, Cr, Cu i Cd) određeni metodom atomske apsorpcione spektrofotometrije (aparat Varian Spectra AA 220 FS) u plamenu acetilen/vazduh. Rezultati istraživanja pokazali su da se sadržaj teških metala u biljnom tkivu značajno smanjivao sa udaljavanjem useva pšenice od zagađivača, ali se tokom vegetacionog perioda povećavao dostigavši najveću vrednost u fazi klasanja biljaka. Korenovi su u svim fenofazama imali više teških metala nego stabla pšenice što ukazuje na činjenicu da su oni u biljnim organima manje pokretni. Razlike u sadržaju teških metala u korenovima bile su najveće poređenjem uzoraka sa polja u sistemu konvencionalne ratarske proizvodnje u odnosu na polja na kojima se hemijska sredstva ne primenjuju (ogledna polja PDS Tamiš). Između genotipova značajna razlika bila je samo pri usvajanju cinka. Tako je Pobeda imala najviše cinka u korenovima i stablima u svim fazama rastenja

intake and deposition of heavy metals in wheat roots and stems, field experiments were conducted in years 2009 and 2010 on four sites. The distances of experimental fields from the Oil Refinery Pančevo varied. The first field was located in Vojlovica (200 meters away), the second one in the agro-industrial complex PK Stari Tamiš (5000 meters) and the third location was at agricultural estate and food processing plant PDS Tamiš on two fields regularly treated with chemicals in accordance with modern agricultural methods and one field not treated with chemicals in the past 20 years. This field was located some 10 000 meters from the Refinery. The subject of this research were four genotypes of winter wheat: Ljiljana, Pobeda (Victory), Renesansa (Renaissance) and Apach (Apache). The samples from the plants-roots and above-ground vegetative biomass-were taken during growth stages of tillering, arranging panicles and earing. Simultaneously with the field experiments, experiments were set up in the laboratory dishes. Soil from the experimental fields used to fill the dishes was previously contaminated with heavy metals Zn, Pb, Cr, Cu and Cd. Also used were these compounds: C4H6O4Pbx3H2O, CuSO4, Cd(NO3)2x4H2O, CrO3 and Zn(CH3COO)2x2H2O. Used the following concentrations: 0 ppm, 50 ppm, 100 ppm, 250 ppm, 500 ppm and 1000 ppm. The dishes were sown with two genotypes Pobeda and Ljiljana and the experiment was set in the greenhouse of the Faculty of Agriculture in Zemun. The samples tested for heavy metals in roots and stems were taken during the periods of tillering and ears forming. The heavy metals Zn, Pb, Cr, Cu and Cd were identified through atomic absorption spectrophotometry (device Varian Spectra AA 220 FS) in acetylene/air flame. The research results have shown that the heavy metal contents in plant tissue decreased significantly with the increase of the distance between the wheat crops and the polluters, however, this content showed steady increase during the vegetative period and peaked in the ears forming earing phase. The roots in all growth stages contained more heavy metals than wheat stems which points to the fact that they are less mobile in the plant organs. The differences shown in the heavy metals content found in the roots were greatest when comparison was made between the samples from the fields within the system of conventional field crop farming and fields where chemicals have not been applied (experimental fields at PDS Tamiš). Among the genotypes the significant difference was shown in adoption of zinc. Thus, Pobeda had the highest content of zinc in roots and stems in all vegetative stages.