International Journal of Agricultural Technology 2016 Vol. 12(3): Available online ISSN (Online)

Transcription

1 Interntionl Journl of Agriulturl Tehnology 216 Vol. 12(3): Aville online ISSN (Online) Effiy of Culture Filtrte from Fusrium oxysporum F221-B ginst Plnt Pthogeni Fungi In Vitro nd Fusrium Root Rot nd Wilt Disese in Hydroponis Thongkmngm, T. nd Jenksorn, T.* Deprtment of Plnt Prodution Tehnology, Fulty of Agriulturl Tehnology, King Mongkut s Institute of Tehnology Ldkrng, Bngkok 152, Thilnd. Thongkmngm, T. nd Jenksorn, T. (216). Effiy of ulture filtrte from Fusrium oxysporum F221-B ginst plnt pthogeni fungi in vitro nd Fusrium root rot nd wilt disese in hydroponis. Interntionl Journl of Agriulturl Tehnology 12(3): Astrt The purpose of this reserh ws to evlute the potentil of ulture filtrte (CF) of non-pthogeni Fusrium oxysporum (F221-B) ginst 1 plnt pthogeni fungi nmely, Curvulri sp. (C11, C12), F. semitetum (F113), F. oxysporum f.sp. ltue (F221-R, F422-G), Rhizotoni spp. (R111, R112, R113) nd R. solni (R11, R12) in vitro nd Fusrium root rot disese in hydroponis. In vitro ntifungl tivity nlysis indited tht ll test onentrtions of F221-B ulture filtrte ould slightly inhiit myelil growth of ll tested fungl pthogens less thn 39 % over ontrol. Interestingly, the CF t ll test onentrtions reveled the gretest spore germintion inhiition 1% over ontrol ginst F113, F221-R nd F422-G wheres spore germintions of C11 nd C12 were ompletely inhiited y the CF t the onentrtions of 6, 8 nd 1%. In ddition, spore normlities suh s swelling nd lysis were noted. Regrd to ntifungl nlysis in hydroponis, the most striking nd remrkle result ws otined. The non-pthogeni F. oxysporum F221-B ws proved to e effiient in reduing disese severity of Fusrium root rot in lettue more thn 9% nd produing signifintly etter growth thn tht in nontreted lettues. Moreover, no signifint degree of differene in terms of lettue growth ws noted etween using ulture filtrte nd spore suspension of F221-B. Keywords: ulture filtrte, non-pthogeni Fusrium oxysporum F221-B, F. oxysporum f.sp. ltue Introdution Biologil ontrol of plnt diseses inluding fungl pthogens hs een onsidered s environmentlly sfe nd vile lterntive mesure to hemil ontrol (Bker, 1987; Cook, 1993; Tjmos et l., 1992). Nonpthogeni speies of the fungl genus Fusrium were numerously reported to suessfully ontrol Fusrium wilt of vrious rops worldwide (Elmer, 24; Lrkin nd Frvel, 1998 nd 22; Nel et l., 26; Silv nd Bettiol, 25). In Thilnd, non-pthogeni F. oxysporum (F221-B), originlly isolted from root of lettue grown in hydroponis, hs shown its ility s plnt growth promoting fungus (PGPF) on vrious rops suh s *Corresponding uthor: Jenksorn, T; Emil: tnimnun@gmil.om

2 Butterhed, Cos, Green ok, Red ok lettues, kle nd mung en (Thongkmngm et l., 213; Thongkmngm nd Jenksorn, 215) nd s ioontrol gent (BCA) ginst plnt pthogeni fungi, nmely Curvulri spp., Colletotrihum spp. nd F. oxysporum f. sp. ltue (Thongkmngm nd Jenksorn, 215). Non-pthogeni F221-B showed remrkle onsisteny in retining its morphology hrteristis nd its effiy s BCA nd PGPF during 24 months storge (Thongkmngm nd Jenksorn, 215). In ddition, F221-B ws proved to e le to olonize on root surfe (epiphyte) s well s inside the root of lettue (endophyte) without produing ny disese symptoms (Thongkmngm nd Jenksorn, 215). Fusrium root rot nd wilt disese ws regrded s one of the most seriously disese of lettue grown in soil nd hydroponi ultivtion (Crl et l., 214; Chint et l., 214; Mlrn nd Mourelos, 214; Sott et l., 214; Thongkmngm et l., 212). The disese ws used y Fusrium oxysporum f.sp. ltue. Effetive ontrol methods ginst this disese re limited wheres hemil ontrol hs dverse effet to the onsumer nd environment. On this regrd, non-pthogeni F221-B would e one of the strong ndidtes s iologil ontrol gent to solve this prolem. Bsed on the ove-mentioned good hrteristis of F221-B s PGPR nd BCA from whih the feture of ntiiosis ws lso oserved in onfronttion experiment etween F221-B nd test fungl pthogens t the erly stge of inution period (Thongkmngm nd Jenksorn, 215), it is interesting to further reserh on the ntifungl ility of seondry metolites in ulture filtrte of non-pthogeni F221-B. Therefore, the reserh ws onduted to determine the potentil of ulture filtrte (CF) of non-pthogeni Fusrium oxysporum (F221-B) ginst 1 plnt pthogeni fungi nmely, Curvulri sp. (C11, C12), F. semitetum (F113), F. oxysporum f.sp. ltue (F221-R, F422-G), Rhizotoni sp. (R11, R12, R13) nd R. solni (R11, R12) in vitro nd Fusrium root rot disese in hydroponis. Mterils nd methods Fungl isoltion The test fungl pthogens were isolted from nturlly infeted disese plnts i.e. Curvulri spp. (C11, C12) nd F. semitetum (F113) from rie seeds showing dirty pnile disese, F. oxysporum f.sp. ltue (F221-R, F422-G) from root of lettue grown in hydroponis showing root rot disese, Rhizotoni spp. (R111, R112, R113) from rie lef shelth showing light disese nd R. solni (R11, R12) from rie seedling, y tissue trnsplnting tehnique on wter gr. The fungi were purified nd mintined on potto dextrose gr (PDA) nd stored t 4 C. 514

3 Interntionl Journl of Agriulturl Tehnology 216 Vol. 12(3): Non-pthogeni Fusrium F221-B ws otined from the previous reserh of Thongkmngm et l. (213). Preprtion of ulture filtrte (CF) of F. oxysporum (F221-B) Regrd to our reserh iming t ssessment for ntifungl tivity of seondry metolites in ulture filtrte of non-pthogeni F. oxysporum (F221-B), only the omplete ell-free ulture filtrte hs to e used in the experiment. Therefore, two types of preprtion for otining the ell-free ulture filtrte were rried out for this regrd: i) using miro-filter (Minisrt ; Srtorius stedim ioteh,.2 µm) nd ii) using moist-het from utolve. To otin filtrtes of the fungl ulture, 5 myelil gr plugs (.5 m in dimeter) of F221-B were inoulted into 25 ml Erlenmeyer flsk ontining 5 ml of potto dextrose roth (PDB) nd the ulture ws inuted t room temperture. After 7 dys, the iomss ws seprted from the roth, whih ontined the fungl metolites, y filtering through Whtmn filter pper no.1 efore eing entrifuged t 1, rpm for 15 minutes. Then, the filtrtes were undergone through the proess of getting the omplete ell-free CF y 2 types of preprtion proedure mentionedove. After tht, the otined ell-free CF ws diluted with sterile distilled wter to give onentrtions of 2, 4, 6 nd 8 % redy to e used. Effet of ell-free ulture filtrte (CF) of F. oxysporum (F 221-B) ginst plnt pthogeni fungi y gr well diffusion ssy To determine the ntifungl tivity of F221-B ulture filtrte t different onentrtions (, 2, 4, 6, 8 nd 1%) on myelil growth of 1 plnt pthogeni fungi, the experiment ws onduted in duplite; i) employing ell-free CF prepred y using miro-filter nd ii) employing ell-free CF prepred y using moist het of utolve. Rndomized Completely Blok Design (RCBD) with 3 replitions ws employed. Ten plnt pthogeni fungi (C11, C12, F113, F221-R, F422-G, R11, R12, R111, R112, nd R113) were ultured on PDA plte nd inuted for 3 dys. Then, 6 holes of 5 mm in dimeter were punhed with sterile ork orer septilly into the gr outside the periphery of pthogen olony. 3 µl of eh onentrtion of F221-B ulture filtrte ws introdued into eh ored gr well. All pltes were inuted t room temperture. The rdil growths of tested pthogens were dily mesured nd the perentge of growth inhiition of tested pthogens ws lulted. 515

4 Effet of ell-free ulture filtrte (CF) of F. oxysporum (F 221-B) on spore germintion of plnt pthogeni fungi To investigte the inhiitory effet of F221-B ulture filtrtes t different onentrtions (, 2, 4, 6, 8 nd 1%) on spore germintion of 5 fungl plnt pthogens, nmely C11, C12, F113, F221-R nd F422-G, the experiment ws performed in duplite; i) employing ell-free CF prepred y using miro-filter nd ii) employing ell-free CF prepred y using moist het of utolve. Completely rndomized design with 2 replitions ws employed. 3 µl of the fungl spores (1 1 6 spore/ml) were pled onto onve glss slides in the presene of 3 µl of ulture filtrtes (onentrtion of, 2, 4, 6, 8 nd 1 perent) nd inuted in the moist hmer in the drk t room temperture (25±2 C). After 12, 24 nd 48 h, the perentge of spore germintion of fungl spores ws determined y light mirosopy. In ddition, the ourrene of spore normlities ws monitored. Effet of ulture filtrte (CF) of F. oxysporum (F 221-B) for ontrolling root rot of lettue in hydroponis Antifungl tivity of F221-B ulture filtrte ws further determined for ontrolling Fusrium root rot disese of lettue grown in hydroponis. The onentrtion of F221-B ulture filtrte to e used in hydroponi experiment ws seleted from the gr well diffusion ssy nd spore germintion test from whih showing high potentil of ntifungl tivity. The experiment ws onduted using ompletely rndomized design of 6 tretments with 3 replitions nd 3 plnts per replition. Tretments omprised of: Tretment 1: Helthy Control (Non-inoulted ontrol) Tretment 2: Inoulted ontrol (with pthogen F422-G) Tretment 3: Culture filtrte of F221-B Tretment 4: Culture filtrte of F221-B + F422-G Tretment 5: Spore suspension of F221-B Tretment 6: Spore suspension of F221-B + F422-G Seeds of Cos lettue were sown in moistened sponge in seed try nd wtered with tp wter for week nd then moved into mini DFT system nd fertilized with nutrient solution (EC=1 ms/m2, ph= ). After 2 weeks, 3 seedlings were trnsplnted into retngulr plsti ontiner ( m) ontining 5 liters of nutrient solution (EC=1.6 ms/m 2, ph= ). At 14 dys, lettues were treted with non-pthogeni F221-B y immersing their root into either ulture filtrte or spore suspension of F221- B (5 ml/plnt) for 5 minutes nd the rest of F221-B ws poured k into the growing ontiner. Sterile wter ws used for ontrol. Three dys lter, 516

5 Interntionl Journl of Agriulturl Tehnology 216 Vol. 12(3): pthogen inoultion ws mde y pouring 15 ml of spore suspension (1 6 spores/ml) of F422-G into growing ontiner. Sterile wter ws used for ontrol. Dt olletion nd nlysis Disese index ws rted up to 6 levels (: helthy root, 1: reddish rown root, 2: reddish rown root nd eme rotten, 3: rotten root, with slight wilting, 4: rotten root with severe wilting, 5: plnt eme ded). Disese inidene (DI) nd disese severity (DS) of tested plnt were lulted y eqution 1 nd 2, respetively. % DI = (Numer of plnts showing infeted root) 1 (1) Numer of totl plnts % DS = (Numer of plnts showing infeted root disese index) 1 (2) Numer of totl plnts the highest disese index DI, DS, s well s plnt growth prmeters suh s lef numer, lef size, hlorophyll ontent (SPAD vlue) on the lef were weekly monitored fter inoultion wheres fresh nd dry weight of shoot nd root were reorded t the end of tril. All olleted dt were sttistilly nlysed y nlysis of vrine. Tretment mens were seprted using Dunn s multiple rnge tests. Results nd Disussion Effet of ell-free ulture filtrte (CF) of F. oxysporum (F 221-B) ginst 1 plnt pthogeni fungi y gr well diffusion ssy Culture filtrte of F221-B ws heked for its effet ginst myelil growth of 1 fungl plnt pthogens y using gr well diffusion ssy. Among 2 types of CF of F221-B, the results reveled tht ell-free ulture filtrte prepred y using either miro-filter or moist-het from utolve still showed the similr level of ntifungl tivity ginst ll tested fungi exept for R11 nd R112 (Fig. 1). This indited the thermo-stle nture of these ntifungl metolites in ulture filtrte produed y F221-B. Surprisingly, utolved CF gve higher inhiition ginst R11 nd R112 thn those from non-utolved CF. Results shown in Fig. 1 reveled tht the ell-free ulture filtrte of F221-B ontined seondry metolites suh s some iotive ompounds tht inhiited the in vitro fungl pthogen growth wheres this inhiitory effet vried depending on the onentrtions of CF tested. F221- B ulture filtrte t ll tested onentrtions exhiited slight inhiitory effet ginst myelil growth of ll tested fungl pthogens in the rnge of 6-39 perent over the untreted ontrol. Overll, mong the tested onentrtions, ulture filtrtes t 8 nd 1 % gve the signifint highest inhiition. 517

6 % Growth inhiition over ontrol Curvulri spp. (C11 nd C12) were shown to e most sensitive to F221-B ulture filtrte. The inhiitory effet of F221-B ulture filtrte ws in ordne with those of Benhmou et l. (22); Hlmnn nd Sikor, (1994); nd Khurshid et l. (214) who reported tht vrious non-pthogeni Fusrium isoltes hve shown their ility to suppress plnt pthogens. Tyung et l. (21) reported tht the metolite produed y endophyti Fusrium (MTCC-9622) showed signifint ntifungl tivity ginst 3 posthrvest pthogens inluding F. oxysporum % 4% 6% 8% 1% Cell-free CF prepred y using utolve Cell-free CF prepred y using mirofilter C11 C12 F113 F221-R F422-G R11 R12 R111 R112 R113 Figure 1. Effet of ell-free ulture filtrte produed y non-pthogeni Fusrium oxysporum F221-B ginst myelil growth of 1 plnt pthogens y gr well diffusion ssy. (C11, C12: Curvulri spp.; F113: F. semitetum; F221-R nd F422-G: F. oxysporum f.sp. ltue; R11 nd R12: R. solni, R111, R112 nd R113: Rhizotoni spp.) Effet of ell-free ulture filtrte (CF) of F. oxysporum (F221-B) on spore germintion of 5 plnt pthogeni fungi Culture filtrte of F221-B ws tested for its ntifungl tivity on spore germintion of 5 fungl plnt pthogens. The result ws in line with the fore-mentioned experiment using gr well diffusion method tht CF of 518

7 Interntionl Journl of Agriulturl Tehnology 216 Vol. 12(3): F221-B prepred using either miro-filter or moist-het from utolve resulted in the sme level of ntifungl tivity ginst the germintion of test fungi (Fig. 2). This reonfirmed one gin tht the toxi metolites in ulture filtrte produed y F221-B re hving thermo-stle nture. A signifint inhiitory effet (1 % inhiition over ontrol) of ll test onentrtions (2, 4, 6, 8 nd 1%) of ell-free ulture filtrte of F221-B on germintion of spores of F. semitetum (F113) nd F. oxysporum f.sp. ltue (F221-R, F422-G) ws evident throughout the experiment (12-48 h) (Fig. 2). However, for the se of Curvulri spp. (C11 nd C12), signifint ntifungl tivity (1 % inhiition over ontrol) of the CF of F221-B ws oserved only t the onentrtion of 6, 8 nd 1 %. In ddition, the level of inhiition of germintion of their spores dded to F221-B ell-free CF t the low onentrtion of 2 nd 4 % delined with inresing time (Fig. 2). This deline ould e held responsile for the deresing levels of voltile sporostti ftors produed y F221-B. As soon s the pperne of voltile ompound ws ended, persistent level of inhiition of spore germintion used y stle inhiitor from nonvoltile ompound ws shown. Furthermore, normlities of spores were deteted suh s swelling, lysis (Fig. 3). In the urrent study, we oserved the signifintly higher degree of inhiitory tivity of F221-B ulture filtrtes ginst spore germintion of ll tested fungi thn those of their myelil growth. This my e ttriuted to the diret exposure of spore to the ulture filtrte. Findings from in vitro experiments onerning the inhiitory effets of ulture filtrtes of F221-B re in greement with severl previous works y Aydi-Ben Adllh et l. (214); Lemneu et l. (1993); Sonwne et l. (215). In ddition, the filtrte of non-pthogeni F. oxysporum ws reported to ountert the growth of Stphyloous ureus using dermtologil disese (Ahmed Sheikh, 21). On the sis of our findings from in vitro studies, it is ssumed tht the ulture filtrte of F221-B tested my lso ontin ntiiotis, toxins nd/ or enzymes ginst the test fungl plnt pthogens. Although the ntifungl metolites in ulture filtrte produed y F221-B hve not een so fr identified hemilly, it is still noteworthy tht thermo-stility of suh metolites hs een oserved from our in vitro experiments. Additionl studies re required to identify the tive ntifungl ompound in F221-B ulture filtrte. 519

8 F422-G C 11 % inhiition of spore germintion over ontrol 2% 4% 6% 8% 1% Cell-free CF prepred y using utolve Cell-free CF prepred y using mirofilter 12h 24h 48h 12h 24h 48h 12h 48h 12h 48h 12h 48h C11 C12 F113 F221-R F422-G Figure 2. Effet ell-free ulture filtrte produed y non-pthogeni F. oxysporum F221-B t different onentrtions (2, 4, 6, 8 nd 1 perent) ginst spore germintion of 5 plnt pthogeni fungi (3 dys fter inoultion). Control CF 8 % CF 1% Figure 3. Anorml spores of Curvulri sp. (C11) nd Fusrium oxysporum f.sp. ltue (F422-G) ourred in ulture filtrte of non-pthogeni F221-B t the onentrtion of 8 nd 1 perent, t 48 h. 52

9 Interntionl Journl of Agriulturl Tehnology 216 Vol. 12(3): Effet of ulture filtrte (CF) of F. oxysporum (F 221-B) for ontrolling Fusrium root rot disese of lettue in hydroponis The experiment ws onduted to investigte the effet of ulture filtrte of non-pthogeni F221-B in ontrolling Fusrium root rot disese of lettue in hydroponis. The result showed tht lettue from noninoulted (helthy) ontrol grew nd developed normlly while lettue treted only with F221-B (ulture filtrte or spore suspension) did not show ny disese symptoms throughout the tril (Tle 1) nd grew signifintly etter thn tht of non-inoulted ontrol (Fig. 4). At 7 dys fter inoultion (), the inoulted lettue with F422-G egn to show symptoms of root rot with 64 % disese inidene (DI) nd 56.1 % disese severity (DS) wheres the lettue treted with ulture filtrte nd spore suspension of non-pthogeni F. oxysporum (F 221-B) prior to pthogen inoultion showed signifint low perentge in DI nd DS out 32, 16 nd 6.6, 3.3 perent, respetively. Regrd to inoulted ontrol, perentge of DI nd DS inresed with inresing inution time; lettues showed severe symptoms of root rot nd wilt with 1% DI t 14 nd DS rehed highest of 93.6% t 28. At 28, pre-tretment with either ulture filtrte or spore suspension of F221-B exhiited signifint inhiition over ontrol of more thn 9 % in DS (Tle 1). In terms of plnt growth, the most pronouned nd sttistilly signifint redution in ll the growth prmeters suh s lef numer, lef size nd SPAD vlue ws reorded only in lettues in inoulted ontrol throughout the tril (Fig. 4) while the tretments with F221-B (either CF or spore) prior to pthogen (F422-G) inoultion resulted in the sme norml growth s tht in non-inoulted ontrol (helthy ontrol) nd in F221-B treted lettue. For overll, non-pthogeni F221-B-treted lettues showed more vigorous root system without pprent of root rot symptom nd finlly resulted in signifintly muh etter growth (fresh weight of stem nd root) thn tht in non-treted lettues. In ddition, spore of F221-B tended to e more effiient thn the ulture filtrte sine the fresh weight nd dry weight of stem nd root of lettue treted with spore of F221-B ws shown to e signifintly greter thn tht in non-inoulted ontrol (Fig. 4). Bsed on our results, non-pthogeni F. oxysporum (F 221-B) ws proved to e effiient in reduing disese severity of Fusrium root rot in lettue nd produing greter growth with no signifint degree of differene etween using ulture filtrte or spore suspension of F221-B. These results re greed with erlier reports of their suess in using nonpthogeni F. oxysporum to ontrol Fusrium wilt of vrious vegetles (Reddy, 213) suh s sprgus (Elmer, 24), sil (Minuto et l., 1997 nd Lrkin nd Frvel, 22), uumer (Mndeel nd Bker, 1991; Pulitz et l., 1987), pe (Benhmou nd Grnd, 21), rdish (Toyot et l., 1995), spinh (Ktsue nd Alsk, 1997), sweet potto (Ogw nd 521

10 Komd, 1984) nd tomto (Lrkin nd Frvel, 1996 nd Silv nd Bettiol, 25). In ddition, our result is similr to tht of Horinouhi et l. (21), who reported tht Fusrium wilt of spinh ws effetively ontrolled y PGPF F. equiseti GF183. These results provide evidene of the ntgonisti tivity of F221-B in ontrolling root rot disese used y F. oxysporum f.sp. ltue (F422-G) nd promoting the overll growth in lettue. Tle 1. Effet of non-pthogeni F. oxysporum (F221-B) in ontrolling root rot of lettue grown in hydroponis. Tretment % Disese inidene (DI) % Disese severity (DS) % Inhiition in DS over ontrol 7 1/ Helthy ontrol 2/ - Inoulted ontrol (F422-G) F221-B (CF) - F221-B (CF)+ F422-G F221-B (Spore) - F221-B (Spore)+F422-G / : Dy fter inoultion, Inoultion ws mde t the ge of plnt of 17 dys. 2/ Mens in olumn followed y the sme letters re not signifintly different ording to Dunn s Multiple Rnge Test t P=

11 Dry weight (g/plnt) Fresh weight (g/plnt) Chlorophyll ontent (SPAD vlue Lef size (m) Lef numer Interntionl Journl of Agriulturl Tehnology 216 Vol. 12(3): dy 31 dy 38 dy 45 dy 24 dy 31 dy 38 dy 45 dy dy 31 dy 38 dy 45 dy Stem Stem Figure 4. Effet of non-pthogeni F. oxysporum (F221-B) on growth of lettue in hydroponis. Root Root 523

12 Figure 5. Effet of non-pthogeni F. oxysporum F221-B (ulture filtrte nd spore suspension) for ontrolling root rot disese of lettue grown in hydroponis (45 dys fter inoultion). Conlusion In this reserh, the potentil of ell-free ulture filtrte of nonpthogeni F. oxysporum (F221-B) ws evluted ginst 1 plnt pthogeni fungi. Among 2 types of ell-free ulture filtrte used, utolved CF for overll still exhiited the sme level of ntifungl tivity ginst test fungi s those from non-utolved CF (using miro-filter). This should e noted tht thermo-stility of ntifungl metolites in ulture filtrte of F221-B hs een oserved from our in vitro experiments. For gr well diffusion ssy, ll test onentrtions of ulture filtrte ould slightly inhiit myelil growth (out 6-39 perent over ontrol) of ll tested fungl pthogens while the promising fungitoxi effet ws reorded only t the onentrtions of 8 nd 1 perent of CF. Similr ut more promising results were otined from the spore germintion test. F221-B ulture filtrte t ll test onentrtions showed exellent spore germintion inhiition 1 % over ontrol ginst F113, F221-R nd F422-G wheres only t 6, 8 nd 1 % of F221-B ulture filtrte were shown to ompletely inhiit the spore germintion of C11 nd C12. Tken together, non-pthogeni F. oxysporum F221-B in the form of either ulture filtrte or spore suspension ws signifintly effiient in ontrolling root rot disese of lettue. In ddition, it signifintly exhiited enefiil effet on overll growth of lettue. Aknowledgements This reserh ws supported y grnts from the Fulty of Agriulturl Tehnology, King Mongkut s Institute of Tehnology Ldkrng, Thilnd in yer 216 (grnt numer ). Referene Ahmed, A. H. M. (21). Antimiroil tivity of ertin teri nd fungi isolted from soil mixed with humn sliv ginst pthogeni miroes using dermtologil diseses. Sudi Journl of Biologil Sienes 17:

13 Interntionl Journl of Agriulturl Tehnology 216 Vol. 12(3): Aydi-Ben Adllh, R., Hssine, M., Jnoun-Khireddine, H., Houl, R. nd Dmi- Remdi, M. (214). Antifungl tivity of ulture filtrtes nd orgni extrts of Aspergillus spp. ginst Pythium ultimum. Tunisin Journl of Plnt Protetion 9:17-3. Bker, K. F. (1987). Evolving onepts of iologil ontrol of plnt pthogens. Annul Review of Phytopthology 25: Benhmou, N. nd Grnd, C. (21). Cytologil nlysis of defense-relted mehnisms indued in pe root tissues in response to oloniztion y non-pthogeni Fusrium oxysporum Fo47. Phytopthology 91: Benhmou, N., Grnd, C. nd Goulet, A. (22). Aility of nonpthogeni Fusrium oxysporum strin Fo47 to indue resistne ginst Pythium ultimum infetion in uumer. Applied nd Environmentl Miroiology 68: Crl, C. S., Brunelli, K. R., Cost, H., Fonse, M. E., Boiteux, L. S. nd Reis, A. (214). Identifition of Fusrium oxysporum f.sp. ltue re 1 s the usl gent of lettue wilt in Brzil. Tropil Plnt Pthology 39: Chint, Y. D., Kno, K., Widistuti, A., Fukhori, M., Kwski, S., Eguhi, Y., Misu, H., Odni, H., Zhou, S., Nrisw, K., Fjiwr, K., Shinohr, M. nd Sto, T. (214). Effet of orn steep liquor on lettue root rot (Fusrium oxysporum f.sp. ltue) in hydroponi ultures. Journl of the Siene of Food nd Agriulture 94: Cook, R. J. (1993). Mking greter use of introdued miroorgnisms for iologil ontrol of plnt pthogens. Annul Review of Phytopthology 31:53-8. Elmer, W. H. (24). Comining nonpthogeni strins of Fusrium oxysporum with sodium hloride to suppress Fusrium rown rot of sprgus in replnted fields. Plnt Pthology 53: Hllmnn, J. nd Sikor, R. A. (1994). Ourrene of plnt prsiti nemtodes nd nonpthogeni speies of Fusrium in tomto plnts in Keny nd their role s mutulisti synergists for iologil ontrol of root knot nemtodes. Interntionl Journl of Pest Mngement 4: Horinouhi, H., Muslim, A. nd Hykumhi, M. (21). Bioontrol of Fusrium wilt of spinh y the plnt growth promoting fungus Fusrium equiseti GF 183. Journl of Plnt Pthology 92: Ktsue, K. nd Alsk, Y. (1997). Control of Fusrium wilt of spinh y trnsplnting seedlings pretreted with non-pthogeni Fusrium oxysporum. Annls of the Phytopthologil Soiety of Jpn 63: Khurshid, S., Shoi, A. nd Jvid, A. (214). In vitro toxiity evlution of ulture filtrtes of Fusrium oxysporum f.sp. lyopersii on growth nd physiology of tomto under hromium (VI) stress. The Journl of Animl nd Plnt Sienes 24: Lrkin, R. P. nd Frvel, D. R. (1996). Effiy of vrious ioontrol orgnisms in the ontrol of Fusrium wilt of tomto. Phytopthology 86: Lrkin, R. P. nd Frvel, D. R. (1998). Effiy of vrious fungl nd teril ioontrol orgnisms for ontrol of Fusrium wilt of tomto. Plnt Disese 82: Lrkin, R. P. nd Frvel, D. R. (22). Redution of Fusrium wilt of hydroponillygrown sil y Fusrium oxysporum strin CS-2. Crop Protetion 21: Lemneu, P., Bker, P. A. H. M., De Kogel, W. J., Alouvette, C. nd Shippers, B. (1993). Antgonisti effet of nonpthogeni Fusrium oxysporum strin Fo47 nd pseudotin 358 upon pthogeni Fusrium oxysporum f.sp. dinthi. Applied Environmentl Miroiology 59: Mlrn, I. nd Mourelos, C. A. (214). Fusrium wilt of lettue used y Fusrium oxysporum f.sp. ltue in Argentin. Plnt Disese 98:

14 Mndeel, Q. nd Bker, R. (1991). Mehnisms involved in iologil ontrol of Fusrium wilt of uumer with strins of non-pthogeni Fusrium oxysporum. Phytopthology 81: Minuto, A., Minuto, G., Migheli, Q., Moioni, M. nd Gullino, M. L. (1997). Effet of ntgonisti Fusrium spp. nd of different ommeril iofungiide formultions on Fusrium wilt of sil (Oimum silium L.). Crop Protetion 16: Nel, B., Steinerg, C., Lushgne, N. nd Viljoen, A. (26). The potentil of nonpthogeni Fusrium oxysporum nd other iologil ontrol orgnisms for suppressing Fusrium wilt of nn. Plnt Pthology 55: Ogw, K. nd Komd, H. (1984). Biologil ontrol of Fusrium wilt of sweet potto y non-pthogeni Fusrium oxysporum. Annls of the Phytopthology Soiety of Jpn 5:1-9. Pulitz, T. Z., Prk, S. nd Bker, B. (1987). Biologil ontrol of Fusrium wilt of uumer with non-pthogeni isoltes of Fusrium oxysporum. Cndin Journl of Miroiology 33: Reddy, P. P. (213). Reent Advnes in Crop Protetion. London: Springer. 268 pp. Sott, J. C., Mroerts, D. N. nd Gordon, T. R. (214). Coloniztion of lettue ultivrs nd rottion rops y Fusrium oxysporum f.sp. ltue, the use of Fusrium wilt of lettue. Plnt Pthology 63: Silv, J. C. nd Bettiol, W. (25). Potentil of non-pthogeni Fusrium oxysporum isoltion for ontrol of Fusrium wilt of tomto. Fitopthologi Brsileir 3: Sonwne, A., Mhjn, M. nd Renke, S. (215). Antifungl tivity of fungl isoltes ginst Pomegrnte wilt pthogen Fusrium. Interntionl Journl of Current Miroiology nd Applied Sienes 2: Tyung, K., Brik, B. P. nd Jh, D. K. (21). Antifungl tivity nd ioontrol potentil of metolite produed y n endophyti Fusrium (MTCC-9622) ginst some posthrvest pthogens. Journl of Agriulturl Tehnology 6: Thongkmngm, T. nd Jenksorn, T. (215). Assessment of viility nd effiy of Fusrium oxysporum (F221-B) s BCA nd PGPF during long term preservtion. Proeedings of the 2 nd Interntionl Symposium on Agriulturl Tehnology, Chonuri, Thilnd, 1-3 July 215. pp Thongkmngm, T. nd Jenksorn, T. (215). Coloniztion of plnt root nd puntured surfe tissue y non-pthogeni nd pthogeni Fusrium oxysporum. Proeedings of the 2 nd Interntionl Symposium on Agriulturl Tehnology. Chonuri, Thilnd, 1-3 July 215. pp Thongkmngn, T., Koohkn, P. nd Jenksorn, T. (212). First report of Fusrium wilt of NFT-grown lettue used y Fusrium oxysporum f.sp. ltue in Thilnd nd its pthogeniity on four vrieties of lettue. Proeedings of the 1 th Nresun Conferene, Phitsnulok, Thilnd. pp Thongkmngn, T., Koohkn, P. nd Jenksorn, T. (213). Fusrium oxysporum F221-B s plnt growth-promoting fungus (PGPF) on six plnts in hydroponis nd its growth hrteristis on different medi. Proeedings of the 6 th Rjmngl University of Tehnology Twn-ok Reserh Conferene, Chonuri, Thilnd. pp Tjmos, E. C., Ppvizs, G. C. nd Cook, R. J. (1992). Biologil Control of Plnt Diseses: Progress nd Chllenges for the Future. New York: Plenum Press. 462 pp. Toyot, K., Kitmur, M. nd Kimur, M. (1995). Suppression of Fusrium oxysporum f.sp. rphni PEG-4 in soil following oloniztion y other Fusrium spp. Soil Biology Biohemistry 27: (Reeived: 31 Mrh 216, epted: 16 April 216) 526