EFFECT OF SOME HEAVY METALS ON GROWTH AND CHEMICAL COMPOSITION OF SOME ORNAMENTAL PLANTS

Abstract

Three sets of :-,:p("rimcmal trials were conducted through(llll two successive ycars(2000/2001 and200ll2002)atthc nursery of Omamcntal Horticulrure Department. Faculty \lf Agicuhurc. Cairo Uni,•crsity.Thcy were intended to lind out the response of three economic omamental plants (Pelargmtium zmwle, Willd : Gm.lmi(l .<ipleudell, llort :tnd Vittca roselt, L) to three heavy metals (Cd,Pb and Ni) and their combination on growth and chemical constituents of the aforementioned plants_ Thus. rooted cuttings of about 15 em. length of Pelnrgouium zmwle, Willd and seedlings of the same length of Gazauia sp/eude11s, Uorr and 1-iuca roseal. were used. They were plant\:d on August 1 11 2000.The plants left to grow at the open field condition till July Jill! 2002.Thr\1ughout the two experimental trials the plants were sprayed with water polluted with determined concentrations of the different heavy metals(Cd,Pb and Ni)at 15 days inten•als commencing from Oct. I !! 2000 i.e. after two months from planting(Cd at 1,2. 4 and 6 ppm.: Pb at 10.25,50 and 75 ppm. and Ni at 2. 4. 8 and 12 ppm.) as well as with spraying every plant species with Pb at 50 ppm.. Cd at-t ppm. and Ni at 8 ppm. as indi,•idual doses tOr studying the combined eOCct of the tlm::e heavy metals. in the same date of spraying. Every plant species sprayed 22 times in every experimental year.The results emplwsized the IOIIowing..c; Pelargouium zoua/e, Willd Using Cd treatments revealed a decrement on most morphological plan! traits.Chlorophyll(al.chlorophyll(b) and carotcnoids \\•ere increased due to using Cd treatments. Indole and phenols content also increased by applying the dillCrent concentrations of Cd with obvi0us increment l(lr using. the highest <.:Clncentration((l ppm.)for indole and with applying the lowest ones (landppm_)fllr phcnols.AII Cd tn:atmcnts increased its accumulation contenr in inflorescenceJeaves. stems and roots with maximum increment with using the highest concentration(6 ppm.).A decrement on plant traits was observed due to applying the dillCrent c0ncentrations or Ph. Chlorophyll(a).chlorophyll(b)and carotcnoids were also increased due to the dillCrent Ph treatments. Moreover. indole and phenols content increased by applying Ph with dear effect with using Pb at 10 ppm. for indole and 25 ppm. for phenols. respecti,•ely. Ph accu!llulations in inflorescence. leaves, stems and roots were increased by treating the plants with the different concenrrations of Pb with maximum increment by using the highest conccntration(75 ppm.). Applying the diflerent Ni treatments revealed a decrement on most plant parameters.Meanwhile.Cillorophyll(a).chlorophyll(h)and carotenoids also increased by Ni treatments. Indole and phenols content revealed also an increment due to Ni treatments.The highest content of indole resulted from Ni treatments at & and 12 ppm.. whereas. the highest phenols content resulted from the lowest concentrati0n(2 ppm.).Ni accumulation in inflorescence, leaves stems and roots were increased by treating the plants with the dilli:rent Ni trcatmcnts.A decrement on most plant traits was detected due to applying the mixture ofCd.Pband Nd.feanwhile.Chlorophyll(a).chlorophyll(b)and carotenoids also increased due to applying the prnil..1u5 treatment.While indole content in lea,•cs was increased due to using the mixture treatment, AlsoJhe same treatment increased the accumulation content of Cd.Pt' and Ni in inflorescence. leaves. stems and roots. Ga;:.attifl spleudens.lfm•t: Using Cd treatments revealed a decrement on most morphological plant traits studied.Chlorophy!l(a).chlorophyll(b)and carotcnoids also decreased hy receiving the plants the dillerent C(lncentrations of Cd.Morevcr.they caused an increment on the accumulation content of Cd in intlorescence. sterns and leaves. \\ith clear enect by using the highest conccntration(6 ppm.).Howevcr, this treatments revealed only a slight increment the accumulation c0ntcnt in roots.Pb treatments in most cases had a decremelll on most morphological plant parameters. lorever. chlorophyll(a).chlorophyll(b)and caroten0ids also decreased by Pb treatments with a dear ellCct hy uSing Pb at ]5 ppm lOr chlorophyll(a) and chlorophyll(b)and 75 ppm.Pb for carotenoids. While.indole content was decreased by Ph applicatilln.phenols content revealed an increment in this concem.A gradual increment on Ph accumulation in inflorescence. lea,•cs and roots \\'US observed due to increasing the concentration of Pb treatments.Also, it re\•ealed an increment in stems by using the dillCrent concerllrations.A gradual decrement was noticed on leaf area. root lengrh and fresh and dry weights of roots,by increasing the concentration of Ni application.However,the other plant traits revealed also a decrement resulting from applying the ditl(;rent Ni treatrnents.Morever.chlorophyll(a),chlorophyll(b) and carotenoids were decreased due to the di!Terent Ni tre ument. The same treatments revealed a decrement on indole content in leaves and incrcmem on phenols.Ni accumulation in intlorcscence.lea,-,.•s.stems and ro(lts was increased resulting from applying the dillCrcnt Ni conccntrations.Using the mixture of Cd.Pb and Ni sl10wcd a decrement on all morphological traits.Chlorophyll(a).chlorophyll(b)and carotenoid$ r wakd :111 mne ent. ;},uc lo,..;ccciviny the r[ants the prcvwus