Effect of lead and cadmium on germination and seedling growth of Leucaena leucocephala

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1 JASEM ISSN All rights reserved Full-text Aville Online t J. Appl. Sci. Environ. Mnge. Septemer, 28 Vol. 12(2) Effect of led nd cdmium on germintion nd seedling growth of Leucen leucocephl 1 MUHAMMAD, SHAFIQ; 1 IQBAL, M. ZAFAR; 2 MOHAMMAD, ATHAR 1 Deprtment of Botny, University of Krchi, Krchi-7527, Pkistn. 2 Cliforni Deprtment of Food And Agriculture, 122 N Street, Room 325, Scrmento, CA 95814, USA (e-mil: triq@cdf.c.gov) ABSTRACT: A study ws conducted to determine the effect of different concentrtions of led nd cdmium on seed germintion nd seedling growth of Leucen leucocephl. Seed were grown under lortory conditions t 25, 5, 75 nd 1 ppm of metl ions of led nd cdmium. Both led nd cdmium tretments showed toxic effects on vrious growth indices of L. leucocephl. Incresing the concentrtion of led to 75 ppm, significntly (p<.5) decresed seed germintion s compred to control. Seedling nd root growth ws significntly (p<.5) reduced t 5 ppm tretment of led. Seed germintion nd root length significntly (p<.5) decresed t 5 ppm tretment of cdmium s compred to control. The seedling dry weight lso significntly (p<.5) reduced t 25 ppm tretment of led nd cdmium. Cdmium tretment t 1 ppm showed comprtively pronounced effects in L. leucocephl seedlings s compred to led. The results of the study suggest tht due to etter metl tolernce indices there is possiility of growing L. leucocephl in res contminted with led nd JASEM Unmnged humn ctivities such s livestock grzing, logging, nd intentionl fire cn result in environmentl degrdtion. Burning of fossil fuel, flooding, mining nd eutrophiction further deteriorte the environment. Degrdtion of environment dversely ffects germintion, growth nd iodiversity of plnts. The environment of the city of Krchi is deteriorting rpidly since the lst couple of decde due to vrious types of pollutnts emitted from vrious types of nthropogenic ctivities ffecting the growth of plnts. Metls re of specil interest with respect to the toxicologicl importnce to humn helth, plnts nd nimls (Azevedo nd Le, 25, Jrup, 23). Led nd cdmium re the toxic elements of primry importnce (Breckle nd Khile, 1992). Led is one of the est known hevy trce elements, with long history of toxicity. Its exposure is ecoming gret concern ecuse of its toxic nture, wide spred occurrence nd long life in iologicl system. The mjor sources of led in soil re usully derived from wethered edrock, prents mteril from led mine, smelting opertions, use of led rsente, use of tetrmethyl led s ntiknocking dditive to petrol (Foy et l., 1978). Led is common hevy metl nd cn e found in tteries, cermics, chemicls nd fertilizers. It is lso used in numer of products including gsoline, hir dyes, leded glss, newsprint, pints, pesticides, pottery nd ruer toys. Inhiition to germintion nd retrdtion of plnt growth hs een reported due to led toxicity (Jffer et l., 1999; Morzeck nd Funicelli, 1982; Wierzick nd Oidzinsk, 1998). Cdmium is common nd trnsitionl metl nd ville in the form of cdmium sulfte is in the environment. Geochemiclly it is quite moile element in soil, wter nd thus freely tken up y plnts. Cdmium is one of highly dispersed metls y humn ctivities (Kt-Pendis nd Dudk, 199). Cdmium hs mny uses in industry nd consumer products, like tteries, pigments, metl cotings, nd plstics. Mny reserch workers hve drwn their ttention on the toxic effects of cdmium on plnt growth (Breckle nd Khile, 1992; Iql nd Mehmood, 1991; Kt-Pendis nd Dudk, 199; Mthur et l., 1987). Leucen leucocephl is economiclly n importnt leguminous plnt with its ility to grow in different environment in the tropics. L. leucocephl hs gret potentil s pstures species providing sources of crude protein nd other importnt nutrients for livestock production (Agng nd Tshwenyne, 23). Little informtion is ville on the effects of hevy metls on seed germintion nd seedling growth of L. leucocephl. The present reserch ws crried out to investigte the effects of led nd cdmium on different growth indices of L. leucocephl. MATERIALS AND METHODS Helthy seeds of L. leucocephl (Lm.) de-wit. were collected from plnts growing t Krchi University Cmpus. Seeds were rued y snd pper to rek the seed dormncy. Seeds were plced in petri dishes (9-mm dimeter) on filter pper (Whtmn # 42) nd were treted seprtely with 2 ml solution of 25, 5, 75 nd 1 ppm led nitrte nd cdmium sulfte. Control tretments were supplied with distilled wter. The experiment ws completely rndomized nd consisted of five tretments replicted three times. The petri dishes were kept t room temperture (28±2 º C) under four 4-Wtt tue lights. Experiment ws concluded fter 1 dys nd vrious growth indices such s seed germintion, root nd seedling length were mesured. Dry weight ws determined fter drying the seedlings in n oven t 72 C for 48 hours. Tolernce indices were determined y the following formul s given y Iql nd Rhmti (1992). Dt for vrious * Corresponding uthor: Muhmmd, Shfiq

2 Effect of led nd cdmium on germintion nd seedling growth of Leucen leucocephl 62 growth indices were sujected to nlysis of vrince nd Duncn's Multiple Rnge Test. RESULTS Led nd cdmium tretment showed toxic effect on seed germintion, seedling growth, root growth nd dry iomss in L. leucocephl s compred to control (Fig. 1-4). Seed germintion, seedling length, root length nd seedling dry weight of L. leucocephl significntly (p<.5) decresed t 1 ppm of led nd cdmium tretment s compred to control (Fig. 1). The effect of vrious tretments of led ws significntly less (p<.5) on seed germintion, root nd seedling growth nd dry mtter ccumultion of L. leucocephl thn vrious tretments of cdmium showing some degree of tolernce to led thn cdmium. Percentge of seed germintion of L. leucocephl ws significntly (p<.5) decresed y led t 75 ppm (Fig. 1). It ws oserved tht 5 ppm led tretment produced significnt (p<.5) effects on seedling nd root length of L. leucocephl s compred to control (Fig. 2). The seedling dry weight of L. leucocephl ws significntly (p<.5) reduced t 25 ppm tretment of led s compred to control. Similrly, 5 ppm cdmium tretment produced significnt (p<.5) effects on seed germintion nd seedling length of L. leucocephl s compred to control (Fig. 3). The root length ws lso significntly (p<.5) decresed t 5 ppm tretment of cdmium. The seedling dry weight of L. leucocephl ws significntly (p<.5) ffected t 25 ppm cdmium tretments s compred to control. The seedlings of L. leucocephl were tested for tolernce to hevy metls, using different concentrtions of led nd cdmium (Fig. 4). L. leucocephl showed high percentge of tolernce t 25 ppm of led s compred to control. Increse in concentrtion of led (5-75 ppm) grdully decresed the tolernce of L. leucocephl. The tretment of led t 1 ppm showed the lowest percentge of tolernce in L. leucocephl. It ws oserved tht cdmium tretment lso produced low percentge of tolernce in L. leucocephl. A high percentge of tolernce ws found in L. leucocephl t 25 ppm cdmium tretment. Incresed in concentrtion of cdmium tretment t 5 ppm reduced the percentge of tolernce. Lowest percentge of tolernce ws found in L. leucocephl t 1 ppm cdmium tretment. According to tolernce test it ws oserved tht tolernce in L. leucocephl t 1 ppm of cdmium ws lower thn led. Cdmium tretment showed comprtively more toxic effects on L. leucocephl seedlings s compred to led Seed germintion (%) P Cd Seedling length (mm) P Cd Root length (mm) P Cd Seedling dry weight (g) P Cd Fig.1. Percentge decrese in seed germintion (%), seedling length (mm), root length (mm) nd seedling dry weight (g) t different concentrtion of led nd cdmium s compred to control. * Corresponding uthor: Muhmmd, Shfiq

3 Effect of led nd cdmium on germintion nd seedling growth of Leucen leucocephl 63 Seed germintion (%) Seedling length (mm) c c C C Root length (mm).45.4 Seedling dry weight (g) c c c C c c C Fig.2. Effect of different concentrtion of led on seed germintion, seedling length, root length nd seedling dry weight of Leucen leucocephl. Vlues followed y the sme letters re not significntly different t p<.5. Seed germintion (%) Seedling length (mm) c cd d C C * Corresponding uthor: Muhmmd, Shfiq

4 Effect of led nd cdmium on germintion nd seedling growth of Leucen leucocephl 64 Seedling dry weight (g) Root length (mm) C C Fig.3. Effect of different concentrtion of cdmium on seed germintion, seedling length, root length nd seedling dry weight of Leucen leucocephl. Vlues followed y the sme letters re not significntly different t p<.5. Tolernce Indices P Cd Fig.4. Indices of tolernce for Leucen leucocephl t different tretments of led nd cdmium. DISCUSSION The plnts under stress conditions re most likely to e dversely ffected y high concentrtion of hevy metls. Led nd cdmium toxicity hs ecome importnt due to their constnt increse in the environment. In the present investigtion, led nd cdmium tretment decresed seed germintion nd seedling growth of L. leucocephl. The decrese in seed germintion of L. leucocephl cn e ttriuted to the ccelerted rekdown of stored food mterils in seed y the ppliction of led nd cdmium. Reduction in seed germintion cn lso e ttriuted to ltertions of selection permeility properties of cell memrne. The decrese in seed germintion of L. leucocephl due to hevy metl tretment is in conformity with the findings of other workers (Ayz nd Kdioglu, 1997; Hsnin et l., 1995; Iql nd Mehmood, 1991; Jml et l., 26, ; Klimuthu nd Siv, 199; Mhmood et l., 25). Klimuthu nd Siv (199) found reduced in seed germintion in corn treted with 2, 5, 1 nd 2 µg ml -1 led cette. Tretment of whet with led t 1, 2, 5, 1 nd 2 mm reduced the germintion process showing grdul reduction in germintion with increse in concentrtion (Hsnin et l., 1995). Excessive mount of toxic element usully cused reduction in plnt growth (Prodgers nd Inskeep, 1981). The wide spred use of cdmium in lrge numer of products nd industril process hs resulted in severe environmentl contmintion. Our * Corresponding uthor: Muhmmd, Shfiq

5 Effect of led nd cdmium on germintion nd seedling growth of Leucen leucocephl 65 knowledge is still insufficient to explin the mechnism of cdmium toxicity nd more especilly the interction of cdmium with importnt iochemicl processes in plnt growth. An ttempt hs een mde to evlute the effect of incresing levels of cdmium toxicity on germintion nd seedling vigor of L. leucocephl. Iql nd Mehmood (1991) reported grdul decrese in plnt growth of Dlergi sissoo with incresing of cdmium level. Mthur et l. (1987) found tht higher concentrtion of cdmium nd chromium (1-25 ppm) ffected germintion nd erly growth performnce of Allium cep. The reson of reduced seedling length in metl tretments could e the reduction in meristemtic cells present in this region nd some enzymes contined in the cotyledon nd endosperms. Cells ecome ctive nd egin to digest nd store food which is converted into solule form nd trnsported to the rdicle nd plumule tips for enzyme mylse which converts strch into sugr nd protese ct on protein. So when ctivities of hydrolytic enzyme re ffected, the food does not rech to the rdicle nd plumule ffecting the seedling length. Led nd cdmium tretment showed greter toxic effects on root growth of L. leucocephl. The reduction in root length in metl tretments could e due to reduced mitotic cells in meristemtic zone of root. Lerd (1992) mde similr oservtions in roots of on Allium cep. These findings confirm tht metl tretment reduced the frequency of mitotic cell in meristemtic zone nd re responsile for inhiition in root growth. The reson for different response of seedling nd root growth to hevy metls is not known ut might e due to rpid ccumultion of hevy metls in root thn shoot or to fster rte of detoxifiction in shoot thn root. Renjini nd Jnrdhnn (1989) oserved tht the growth rte of root, shoot nd formtion of lterl root were retrded with increse in the concentrtion of cdmium cette in penut. Breckle nd Khile (1992) reported tht comined tretment of 2 ppm led nd 1 ppm cdmium gretly reduced the growth of young roots of Fgus sylvtic thn in tretment where metls were pplied seprtely. The effects of toxic sustnces on plnts re dependent on the mount of toxic sustnce tken up from the given environment. The toxicity of some of the metls my e lrge enough tht plnt growth is retrded efore lrge quntities of the element cn e trnslocted (Hghiri, 1973). L. leucocephl seedlings showed grdul decrese in dry weight with increse in concentrtion of led nd cdmium. Led nd cdmium tretment showed significnt effect on seedling dry weight, which ws evident in the poor growth of roots nd eril prts. Cdmium tretment t 25ppm concentrtion showed reduction in dry weight of L. leucocephl seedlings. Reduction in growth prmeters lso leds to decresed dry iomss. Tolernce test showed tht tolernce to led nd cdmium in L. leucocephl ws low t 1 ppm s compred to control. The reson for low tolernce ginst oth metls might e due to chnges in the physiologicl mechnism in seed germintion nd seedling growth of plnt. Shfiq nd Iql (25) reported similr results for low tolernce in Cssi sime seedlings t 1 ppm of led nd cdmium tretment s compred to control. L. leucocephl ws found comprtively tolernt species to led thn cdmium tretment. The results of the study suggest tht due to etter metl tolernce indices there is possiility of growing L. leucocephl in res contminted with led nd cdmium. REFERENCES Agng, AA; Tshwenyne, SO (23). Lucerne, ll nd Leucen leucocephl forges: Production nd utiliztion for livestock production. Pk. J. Nutr., 2: Ayz, FA; Kdioglu, A (1997). Effects of hevy metls (Zn, Cd, Cu, Hg) on the solule protein nds of germinting Lens esculent L. seeds. Turkish J. Bot. 21: Azevedo, RA; Le, PJ (25). Toxic metls in plnts. Brz. J. Plnt Physiol. 17:1. Breckle, S.W; Khile, H (1992). Effects of toxic hevy metls, Cd, P on growth nd minerl nutrition of eech (Fgus sylvtic L.). Vegettio, 11: Foy, CD; Chney, RL; White, MC (1978). The physiology of metl toxicity in plnts. Annu. Rev. Plnt Physiol. 29: Hghiri, F (1973). Cdmium uptke y plnts. J. Environ. Qulity, 2: Hsnin, SH; Sleem, F; Sri, N (1995). Biotechnology for Environment nd Agriculture. University of Krchi, Krchi, Pkistn. Iql, MZ; Mehmood, T (1991). Influence of cdmium toxicity on germintion nd growth of some common trees. Pk. J. Sci. Ind. Res. 34: Iql, MZ; Rhmti, K (1992). Tolernce of Alizi leeck to Cu nd Fe ppliction. Ekologi (CSFR), 11: Jffer, TMR; Eltye, EA; Frooq, SA; Alhry, SN (1999). Led pollution levels in Sultnte of * Corresponding uthor: Muhmmd, Shfiq

6 Effect of led nd cdmium on germintion nd seedling growth of Leucen leucocephl 66 Omn nd its effect on plnt growth nd development. Pk. J. Biol. Sci. 2: Jml, SN; Iql, MZ; Athr, M (26-). Evlution of two whet vrieties for phytotoxic effect of mercury on seed germintion nd seedling growth. Agric. Consp. Sci. 71: Jml, SN; Iql, M.Z Athr, M (26-). Effect of luminum nd chromium on the growth nd germintion of mesquite (Prosopis juliflor (Swrtz.) DC). Internt. J. Environ. Sci. Technol. 3: Jrup, L (23). Hzrd of hevy metl contmintion. Brz. Med. Bull. 68:182. Kt-Pendis, A; Dudk, S (199). Evluting seline dt for cdmium in soils nd plnts in Polnd. In: Element concentrtion cdsters in ecosystems. (Ed. Lieth, H. nd Mrkert, B.). VCH Verlgsgesllschft, Federl Repulic of Germny. Klimuthu, K; Siv, SR (199). Physiologicl effects of hevy metls on Ze mys (mize) seedlings. Indin J.Plnt Physiol. 33: Lerd, D (1992). The effect of led on Allium cep L. Muttion Res. 231: Mhmood, S; Hussin, A; Seed, Z; Athr, M (25). Germintion nd seedling growth of corn (Ze mys L.) under vrying levels of copper nd zinc. Internt. J. Environ. Sci. Technol. 2: Morzeck, JRE; Funicelli, NA (1982). Effect of zinc nd led on germintion of Sprtin lterniflor Loisel seeds t vrious slinities. Environ. Exp. Bot. 22: Prodgers, RA; Inskeep, WP (1981). Hevy metls tolernce of inlnd slt grss Distichlis spict. Gret Bsin Nturlist, 51: Renjini, MBJ; Jnrdhnn, K (1989). Effect of hevy metls on seed germintion nd erly seedlings growth of groundnut, sunflower nd gingerly. Geoios, 16: Shfiq, M; Iql, MZ (25). The toxicity effects of hevy metls on germintion nd seedling growth of Cssi sime Lmk. J. New Seeds, 7: Wierzick, M; Oidzinsk, J (1998). The effect of led on seed imiition nd germintion in different plnt species. Plnt Sci. 137: Mthur, KC; Srivstv, RK; Chudhry, K (1987). Effect of Cd nd Cr metls on germintion nd erly growth performnce of Allium cep seeds. Proc. Nt. Acd. Sci. Indi. Sect. B (Biol. Sci.), 57: * Corresponding uthor: Muhmmd, Shfiq