Stimulatory effects of wheat (Triticum aestivum L.) on seed germination of Orobanche minor Sm.

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1 /94 US $ 5. Allelopthy Journl 3 (2): (212) Interntionl Allelopthy Fountion 212 Tles: 2, Figs : 3 Stimultory effets of whet (Tritium estivum L.) on see germintion of Oronhe minor Sm. S. Q. DONG, Y. Q. MA *1, H. WU 2, J. F. SHUI 1 n Z. Q. HAO College of Resoures n Environment, Northwest A & F University, Yngling, Shnxi Provine, 7121, Chin E. Mil: myongqing@ms.isw..n (Reeive in revise form: Septemer 19, 212) ABSTRACT The effets of winter whet vrieties exutes were teste on the germintion of Oronhe minor sees through hyroponil ulture n fiel experiments. The results inite tht llelopthi potentil of whet on stimulting O. minor sees germintion vrie with teste vrieties, growth stges, extrtion solvents n extrt onentrtions. The methnoli extrts of ll whet vrieties isplye stronger inution of O. minor sees germintion thn the queous extrts. The queous extrts t 1% n 1% effetively stimulte the germintion, ut the unilute (1%) n.1% extrts i not inue the see germintion. Likewise, the methnoli extrts lso inue the sees germintion. The methnoli extrt of vriety `Xioyn No. 22 inue O. minor see germintion up to 56.8%. Thus O. minor sees oul e inue to germinte y the queous n methnoli extrts of winter whet vrieties. Winter whet espeilly t the seeling n heing stges ontine llelopthi sustnes to inue O. minor sees germintion. It is possile tht whet llelopthy oul e use to stimulte the germintion of O. minor, therey rpily epleting the see nk of this prolemti prsiti wee. Keywor: Whet, llelopthi stimultion, Oronhe minor, ftl germintion, roots exutes. INTRODUCTION Oronhe minor (Oronhee) is prsiti ngiosperm, whose hosts rnge inlues memers of the Apiee, Asteree, Fee n Solnee plnt fmilies (7,14,2). It is n oligte root-prsiti plnt without hlorophyll, prsitize mny host speies n ssimilte nutrition from them. As n nnul it reproues y sees n n proue >5, sees per flowering stlk (17). The sees re so smll, hene re esily spre y win, wter, n frm mhinery. The sees hve speil requirements for germintion, i.e., fter-ripening, pre-onitioning, n stimulnts from host plnts or some non-host plnts (1). Its sees remin vile in soil for more thn 1-yers until meeting host plnt(s) (14). O. minor elertes its prsiti response, t the ost of growth n even the eth of host plnts (6,15,26). Control n erition of O. minor is very expensive, time-onsuming n ineffetive. However, whet exutes stimulte the O. minor germintion (2). O. minor sees germinte ut i not evelop tuerles when grown together with the non-host whet plnts (21). Whet therefore hs the potentil to * Corresponene uthor, 1 The Stte Key L. of Soil Erosion n Dryln Frming in the Loess Plteu, Institute of Soil n Wter Conservtion, Northwest A & F University, Yngling, Shnxi 7121, Chin. 2 EH Grhm Centre for Agriulturl Innovtion, Chrles Sturt University, Wgg Wgg, NSW 265, Austrli.

2 248 Dong et l e effetively integrte into n O. minor mngement system (11). This ioontrol metho oul reue Oronhe see nk in soil, therey ringing itionl enefits to the environment n griulturl systems. Distille wter n methnoli extrts of the rhizosphere soil of winter whet oul stimulte the O. minor sees germintion (5), ut it is not known tht exutes of whih growth stge(s) of winter whet re more stimultory to germintion. Previous reserh hs shown tht whet (Tritium estivum L.) possesses llelopthi potentil (3,4,12). Whet ffets other plnts in its viinity, it is lso utotoxi through the exution or relese of seonry metolites y living n e plnts. Hiks et l. (8) reporte tht wter extrt of whet resiues exhiite toxiity to surrouning plnts. Its strw extrts impire the sees germintion n yiels of otton (8). However, whet strw mulh h more signifint effet on wee germintion thn no mulh (18). Different whet vrieties iffer in their llelopthi tivities. Stuies on llelopthi potentil of vrious whet genotypes (strw n eril prts), showe tht whet llelopthy ws enhne with the evolution from iploi to hexploi (31,32). The inhiitory effets of whet llelopthy hve een extensively exploite in iologil wee mngement. However, the stimultory effets of whet llelopthy hve rrely een stuie for its potentil in wee mngement. This reserh ime to etermine, if the stimulnts proue y root or shoot tissues of winter whet exhiit llelopthi effet to inue O. minor through hyroponi ulture n fiel experiments. MATERIALS AND METHODS 1. Hyroponi ulture n olletion of whet root exutes Five winter whet vrieties: Bim No. 1, Fenghn No. 3, Ningong No. 1, Chngwu No. 131 n Xioyn No. 22 (relese in 195s, 196s, 197s, 198s n 199s, respetively) were otine from College of Agriulturl Siene of our University. Four hunre sees of eh vriety were ple into plsti ontiner ( m) line with sheet of guze lothing ple in lrge ontiner ( m) with 4 L tp wter. Smller ontiner ws kept in igger ontiner for 22 ys to provie more spe to whet roots. The plnts were grown in the growth hmer for 2-weeks to ollet the root exutes relese into wter, s the exutes were sore y tivte hrol. One hunre g tivte hrol ws ple into regent ottle (1 ml) n wter ws irulte y using irultion pump etween ottle n ontiner (Chin RS Eletril, RS-3 qurium super pump). The wter with 1 mm of CCl 2 n tivte hrol ws reple fter every two ys. The tivte hrol ontining sore exutes were filtere to remove exess wter. Root exutes sore onto the hrol were elute with etone (3 ml). The etone ws remove y vuum evportion in rotry evportor t 4, the resiue ws trnsferre into 5 ml volumetri flsk n rought to volume y istille wter, then prtitione 5- times with 5 ml ethyl ette (EtOA) in seprting funnel. The EtOA phses were omine n onentrte y vuum evportion to ryness. The rie resiues were suspene in 5 ml etone n store in sele glss vils t 4.

3 Stimultory effets of whet on see germintion of Oronhe minor 249 After the hyroponi ulture, the whet seelings were ollete n seprte into root n shoot tissues, n then were freeze-rie for 48 h y low-temperture vuum freezing ryer n groun y using herl meiine griner (FW , Tinjin Tisite Instrument Co., LTD) n psse through (.45 mm) sieve. Root or shoot power (.1 g) were seprtely e into istille wter (1 ml) or methnol (1 ml), n extrte for 3 min y sonitor. The solution ws entrifuge t 6,4 rpm for 2 min. y miro entrifugl mhine (Millipore Ct. No. XX42 CF, 6 Lot No. N8JMB42A, Nihon Millipore LTD. Yonezw, Jpn). The superntnt ws tken s the originl extrt (9). 2. Colletion of rhizosphere soils n whole plnt mterils The rhizosphere soil ws efine the soil etween the root n soil < 5 mm (19). A ompletely rnomize esign ws use with three replitions. The winter whet vrieties were sown in tril plots (3 2 m) t the Institute of Soil n Wter Conservtion (18 8 E, N, n elevtion 5 m), Northwest Agriulture & Forestry University, Yngling, Shnxi Provine, Chin. The experimentl soil is rk loessil soil [ph (wter) of 8.2; 1.54% orgni mtter;.54% ville N n.27% ville P]. Whet ws sown t 1 kg/h on 5 Otoer, 29 n hrveste on 1 June, 21. The rhizosphere soils n whole plnts of whet were ollete t 5- phenologil phses, [seeling, tillering, jointing, heing n mturity stges]. Whole whet plnts were freeze-rie, groun n psse through.45 mm sieve s esrie ove. The finl power ws store t -5 for further tests. The tretments were replite three times. Whet plnt power (.1 g) ollete from eh 5 - growth stges ws extrte with either istille wter or methnol (1 ml) s esrie ove. After entrifugtion, the superntnt ws tken s the originl extrt (9). 3. Pre-onitioning of Oronhe minor sees O. minor sees were ollete from the fiels of Utsunomiy University, Jpn. Sees of O. minor were isinfete y 1% NClO solution for 3 min, n 75% (V/V) ethnol for 3 min, respetively (16). To improve the germintion of O. minor, the see ws pre-trete with 1-4 mol/l GA 3 (Gierelli i) to rek the ormny (6). Eh petri ish (9 mm i), ws line with oule filter ppers n then e with 5 ml 1-4 mol/l GA 3. Glss fier filter isks for O. minor sees of 5 mm i (Whtmn GF/A GE Helthre UK LTD, Bukinghmshire, UK) were rrnge evenly on the filter pper. 15 isks were put in eh Petri ish. Aout 2-4 sees of O. minor were sown on eh isk. Petri ishes were then sele y Prfilm to reue evportion n ple in n eletrothermi onstnt-temperture inutor for 8 ys with the onstnt temperture of 25 (3). The pre-onitione sees of O. minor were use in germintion iossys elow. 4. Allelopthi stimultion of O. minor sees A stnr germintion-stimulting ompoun GR24 ws provie y Prof. Binne Zwnenurg, Rou University, Nijmegen, Netherlns. Preliminry stuies showe tht 8-9% O. minor sees germinte y GR24 t 1 mg/l onentrtion, while no germintion ourre in sees with only istille wter, initing tht O. minor sees

4 25 Dong et l re vile. The etone solutions (5 ml) ontining the onentrte exutes ollete from the ove mentione hyroponi ulture ws ilute to 1 mg/l, 1 mg/l n 1 mg/l y utolve istille wter. The originl extrt (1%) from whet plnts ws lso ilute to 1%, 1% n.1% y utolve istille wter or methnol, oringly. Twelve pre-trete ulture isks (4- onentrtions n 3- replitions, isks) with O. minor sees were trnsferre in eh petri ish, ifferent onentrtion of istille wter extrts or the etone ilute solutions of the root exutes (15 µl) were then e onto the isk s per tretments. The methnoli extrts (3 µl) were e onto the new glss fier filter isk (no sees), then expose t room temperture on len enh for 3 min. to evporte methnol. At lst, the pre-trete ulture isk with O. minor see ws ple on top of glss fier filter isk. Distille wter (3 µl) ws e onto the oule glss fier filter isk (9). The tretments were replite thrie. The istille wter, methnol n GR24 (1 mg/l) were the ontrol tretments. Petri ishes were then sele y Prfilm to reue evportion n ple in the eletrothermi onstnt-temperture inutor for 1 ys t 25. The germintion rtes of O. minor sees were then oserve through the mirosope (eyepiee 2, ojetive 1 ). Ten g rhizosphere soils (fresh smple) were ple in ulture ishes (3 mm i), 5- pre-trete ulture isks with O. minor sees were refully trnsferre onto the surfe of soil n 1 ml istille wter ws e to eh isk to keep it moist. The soil (without plnt) n GR24 (1 mg/l) serve s ontrol tretment. Eh soil smple ws replite thrie. All ulture ishes were then ple in the inutor for 1 ys t onstnt temperture of 25. The germintion rtes of O. minor sees were reore s esrie ove. Sttistil nlyses: ANOVA nlysis n ll tretment in the figures n tles were performe using SAS 8.1 n Exel 23. Also, LSD.5 ws provie. RESULTS AND DISCUSSION Root exutes Root exutes of whet vrieties signifintly stimulte the O. minor sees germintion (Tle 1). O. minor sees i not germinte in istille wter (ontrol) n t 1 mg/l onentrtion. However, the germintion ws signifintly promote t 1 n 1 mg/l exutes onentrtions, with mximum germintion t 1 mg/l onentrtion. Whet vrieties iffere in stimultory effets on O. minor germintion. At 1 mg/l exutes onentrtion, the vriety Bim No. 1 ws lest stimultory n the Chngwu No. 131 ws the most. The stimultory ility of Xioyn No. 22 ws similr to stnr ompoun GR 24. The stimulnt(s) of O. minor sees germintion from exutes of whet n e prtitione into EtOA phses s shown in Figure 1. After 3-times prtitioning, wter phse i not stimulte the O. minor sees germintion. The results lso showe tht omine EtOA extrts stimulte the germintion. This inite tht EtOA oul e useful regent to isolte the stimulnt(s) from exutes of whet (Fig. 1).

5 Stimultory effets of whet on see germintion of Oronhe minor 251

6 252 Dong et l The extrts of roots or shoots from the hyroponilly ulture seelings i not stimulte the O. minor see germintion, ut the extrts of seelings from fiel use stimultion. One of the resons is tht uner hyroponi onitions, the seeling were grown t higher temperture (25 ) thn seelings grown in fiel (< 1 ), the tive sustnes my e eompose t higher temperture (14). Seonly the whet seeling my exue inhiitory sustnes ginst the O. minor sees germintion, in hyroponi onition, these inhiitory sustnes were not egre y miroorgnisms, ut in fiel onitions, the soil miroorgnisms my egre these sustnes efore they ffet the O. minor sees (1). Aqueous extrts In 1% extrts, the germintion of O. minor sees iffere mong the vrious winter whet vrieties (Fig. 2). At seeling stge, Fenghn No. 3, Ningong No. 1 n Chngwu No. 131 stimulte the O. minor sees germintion. At tillering stge, Xioyn No. 22 ws most stimultory to O. minor sees germintion thn other phonologil stges, exept for Fenghn No. 3. At jointing stge, the germintion rte of O. minor sees ws highest (14.7%) from Xioyn No. 22 extrts, other whet vrieties use less llelopthi stimultion. At heing n mturity stges, O. minor see germintion ws only 1% or lower, whih inite tht whet seelings my synthesize more sustnes for sees n proue less seonry metolites t these stges. Likewise with 1% extrts, some vrieties i not stimulte the O. minor sees germintion (Fig. 2). At seeling stge, extrts of Xioyn No. 22 showe higher germintion of O. minor sees. At tillering stge, Fenghn No. 3 isplye lower stimultion (5.2%) in O. minor sees, ompre with 23.3% in 1% extrt. But Chngwu No. 131 inrese twie in llelopthi stimultion to 1% solution. At heing stge, only Fenghn No. 3 n Xioyn No. 22 stimulte the sees germintion. At other stges, ll vrieties i not inue O. minor sees germintion. Methnoli extrts The methnoli extrts of whole plnt of whet vrieties stimulte the O. minor sees germintion (Tle 2), whose rte ws expresse in inverse S shpe with the ilute onentrtions. But the.1% extrts i not use germintion of O. minor sees. Espeilly, t seeling n jointing stges, unilute methnoli extrts of vrious onentrtions from ll whet mterils stimulte the germintion of O. minor sees. The unilute methnoli extrts of vriety Xioyn No. 22 t seeling, jointing n heing stges use mximum stimultion in germintion of O. minor sees (Tle 2). The extrts t heing use 56.8% stimultion in O. minor sees. Allelopthi stimultion epene on whet vrieties n growth stges, e.g. in 5- test whet vrieties, the germintion ws highest t heing stge, exept in Chngwu No The results suggeste tht winter whet exue more llelopthi sustnes for stimulting the O. minor sees germintion t heing stge. The stok solution (1%) of wter extrts i not stimulte the O. minor sees germintion. Perhps the stok solution (1%) of wter extrts h high osmoti potentil whih inhiite the germintion of P. minor sees. But the methnoli extrts (1%) n stimulte see germintion, euse the methnol from the isks of

7 Stimultory effets of whet on see germintion of Oronhe minor 253 Germintion of O. minor (%) Germintion of O. minor (%) Germintion of O. minor (%) Germintion of O. minor (%) Germintion of O. minor (%) Germintion of O. minor (%) Germintion of O. minor (%) Germintion of O. minor (%) Germintion of O. minor (%) Germintion of O. minor (%) 5 E to A p h se e f E 1 E 2 E 3 E 4 E 5 E M 5 W t e r p h s e B i m N o F eng h n N o N i n g on g N o C h ng w u N o U E W 1 W 2 W 3 W 4 W 5 X i o y n N o. 2 2 Figure 1. Stimultory effets of whet vrieties exutes (EtOA n wter phses) on germintion O. minor sees. E 1: First prtitioning of EtOA, E 2, 3, 4 n 5 my e eue y nlogy. E M: Mixture of five times EtOA phse. UE: Unprtitione exutes, W 1: Wter phse fter the 1 st EtOA prtitioning, W 2, 3, 4 n 5 my e eue y nlogy. The signifint ifferene t 5% (LSD, P <.5) is mrke y the smll letters respetively. If ny letter mrke in one tretment is the sme s the other one, it inites no signifint ifferenes etween them.

8 254 Dong et l Germintion of O. minor (%) Germintion of O. minor (%) Germintion of O. minor (%) Germintion of O. minor (%) Germintion of O. minor (%) Germintion of O. minor (%) Germintion of O. minor (%) Germintion of O. minor (%) Germintion of O. minor (%) Germintion of O. minor (%) A q ueo us ext r t s See ling stg e T il le ri ng s t g e Join ting stg e H e i n g s t ge B M F C N D C W X Y 2 1 M tu rit y s t ge M ethn ol extrts B M F C N D C W X Y Figure 2. Stimultory effets of Aqueous n methnol extrts of whet vrieties prepre t vrious growth stges on germintion of O. minor sees. Whet vrieties BM: Bim No. 1, FC: Fenghn No. 3, ND: Ningong No. 1, CW: Chngwu No. 131 n XY: Xioyn No. 22. Dilute onentrtion of originl extrt (1%: ilution 1-fols, 1%: ilution 1-fols). The signifint ifferene t 5% (LSD, P <.5) is mrke y the smll letters respetively. If ny letter mrke in one tretment is the sme s the other one (in sme olour olumn), it inites no signifint ifferenes etween them.

9 Stimultory effets of whet on see germintion of Oronhe minor 255 methnoli extrt ws evporte for 3 min t room temperture. Then nother isk ontining O. minor sees ws ple on its top n utolve istille wter ws e on the oule isks. During this proess the inhiitory sustnes present in extrts my not remin stle n egre, so the methnoli extrt (1%) my stimulte see germintion. The 1% methnoli extrts of ll whet vrieties stimulte the O. minor sees germintion thn 1% onentrtion (Fig. 2). At 1% onentrtion, the germintion ws higher with extrts from seeling stge of 5-vrieties (Bim No. 1 ws 43.6%, Fenghn No. 3 ws 76.3%, Ningong No. 1 ws 41.2%, Chngwu No. 131 ws 5.9% n Xioyn No. 22 ws 6.8%) of whole plnt methnoli extrts thn other growth stges. The seeling stge extrts of Fenghn No. 3 prove most stimultory (76.3% germintion) to O. minor sees. Likewise, Chngwu No. 131 vriety lso enhne the llelopthi stimultion with the ilutions. At mturity, there were no signifint ifferenes mong the 5- test vrieties of whet. Rhizosphere soil Rhizosphere soil signifintly stimulte the O. minor sees germintion, epening on the whet vrieties. The sees germintion of whet vrieties inrese up to some phenologil phse n then erese. In Xioyn No. 22 n Bim No. 1 germintion inrese from seeing to tillering n erese fter tillering. In Fenghn No. 3, Ningong No. 1 n Chngwu No. 131 germintion inrese from seeing to jointing n erese fter jointing. Among the 5-winter whet vrieties, Xioyn No. 22 ws most stimultory to O. minor sees germintion t seeling, tillering n jointing stges. It hieve the highest stimultion in germintion (49.8%) t tillering stge. The germintion peke t tillering stge for Xioyn No. 22 n Bim No. 1 n t jointing stge for the remining three vrieties. There ws no germintion with mturity stge extrts in ll test vrieties (Fig. 3). This stuy showe tht O. minor see germintion ws stimulte y the istille wter n methnoli extrts of whole plnt of ifferent winter whet vrieties. It suggests tht winter whet oul serete llelopthi ompouns to inue O. minor sees germintion, espeilly, t seeling n heing stge. Distille wter n methnoli extrts of winter whet rhizosphere soil, Ningong No. 1 (197 s) n Xioyn No. 22 (199 s) vrieties throughout their life stimulte the O. minor germintion. Ningong No. 1 ws the est vriety for sowing in the O. minor infeste fiels s it use the highest sees germintion (5). Putnm et l. (1983) propose tht the rop resiues s over exhiite up to 95% ontrol of wees for 3 to 6 ys (18). Steinsiek et l. (1982) evlute the llelopthi potentil of whet strw resiue on the germintion n seeling growth of six wee speies, n reporte tht the extrts prepre y gitting n soking use greter inhiition thn those otine y lehing (24). Whet queous extrts of resiues h llelopthi tivities on growth of mny wees (13,22, 23). Wu et l. (1998) reporte tht oth germintion n root growth of nnul ryegrss (Lolium rigium) were signifintly inhiite y the queous shoot extrts of whet vrieties n their inhiition in ril elongtion ws 19.2% to 98.7% n for see germintion (4.2% to 73.2%), epening on the vriety (29). Besies whet with high levels of phenoli is in the roots were very inhiitory to growth of nnul ryegrss (27). Wu et l. (1999) oumente tht rops oul inhiit wee

10 256 Dong et l Germintion of O. minor (%) Bim No.1 Fenghn No.3 Ningong No.1 Chngwu No.131 Xioyn No.22 Seeling Tillering Jointing Heing Mturity The growth stge of winter whet Figure 3. O. minor germintion (%) inue y rhizosphere soil of winter whet. The signifint ifferene t 5% (LSD, P <.5) is mrke y the smll letters respetively. If ny letter mrke in one tretment is the sme s the other one (in the sme growth stge), it implies no signifint ifferenes etween them. growth y proution n relese of llelohemils into the environment (28). Allelopthi effets of Xioyn No. 22 (199s) in the top-soil (2-2 m) inrese with growth stges (25). Xioyn No. 22 oul provie possile iologil ontrol of O. minor y stimulting its germintion. The whet shoul e plnte s trp rop to reue the see nk of O. minor in soil y using suiil germintion of sees, therey proviing n eologil n sustinle mehnism to erite this prsiti wee. ACKNOWLEDGEMENTS We knowlege the finnil support of the Ntionl Twelfth Five-Yer Pln Siene n Tehnology projets (211BAD31B5) n the projet of The Stte Key Lortory of Soil Erosion n Dry ln Frming on Loess Plteu (152). We thnk Prof. A. Egriny Eneji of the University of Clr, Nigeri for ritil reing n English lnguge eiting of the mnusript. REFFERENCES 1. Brin, J.R., Fermor, T.R. n Semple, K.T. (22). Inution of PAH-tolism in mushroom ompost n its use in the ioegrtion of soil-ssoite phennthrene. Environmentl Pollution 118:

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