Control of Rhizoctonia and Pythium on soybeans (Glycine max) using Trichoderma and silicon

Transcription

1 Control of Rhizotoni n Pythium on soyens (Glyine mx) using Trihoerm n silion R. Bosse, P.M. Clwell *, S. Yoo n M.D. Ling Shool of Agriulturl Sienes n Agriusiness, Disipline of Plnt Pthology, University of KwZulu-Ntl, P/Bg X01, Pietermritzurg, South Afri, Reeive. Aknowlegements The uthors woul like to thnk the Protein Reserh Fountion (PRF) n the NRF for funing this reserh. * To whom orresponene shoul e resse (E-mil:Clwellp@ukzn..z) 1

2 Control of Rhizotoni solni n Pythium on soyens using Trihoerm n silion Rhizotoni solni n Pythium spp. re the usl orgnisms of see n seeling iseses of mny rops. Silion (Si) hs een shown to t s omponent in plnt resistne ginst ioti n ioti stresses n to tivte host efene responses. The im of this tril ws to investigte the growth promotion tivities of Si n Trihoerm (Eo-T ) on soyens. The ontrol of R. solni n Pythium ws lso investigte. Five tretments were investigte, i.e., 200 mg l -1 Si, Eo-T, 200 mg l -1 Si plus Eo-T, ontrol n KOH (to investigte the possile effets of potssium in the potssium silite). Pot trils were use to mesure the shoot iomss of the plnts, while rhizotrons were use to mesure root re, root iomss n root length. Growth promotion stuies showe tht the pplition of 200 mg l -1 Si plus Eo-T resulte in signifint inrese in shoot iomss (22.45 g), root re (14.66 m 2 ), root iomss (0.22 g) n root length ( m) ompre to the ontrol (14.64 g, 7.32 m 2, 0.15g n m), respetively. Similr results were foun in the Pythium ontrol trils where the pplition of 200 mg l -1 Si plus Eo-T lso showe signifint inrese in shoot iomss (19.74 g), root re (9.77 m 2 ), root iomss (0.093 g) n root length ( m) ompre to the inoulte ontrol (9.09 g, 5.74 m 2, g n m), respetively. For the Rhizotoni ontrol trils this pttern ws repete with similr results s pplition of 200 mg l -1 Si plus Eo-T lso showe signifint inrese in shoot iomss (20.45 g), root re (8.98 m 2 ), root iomss (0.094 g) n root length (131.2 m) ompre to the ontrol (7.45 g, 5.05 m 2, g n m), respetively. It ppers tht Eo-T protets the see ginst Rhizotoni n Pythium efore root evelopment, ut 2

3 one roots evelop, the Si tken up y the plnt prevents pthogens penetrting the root re s well s possily inuing host efene retions. Keywors: Pythium, Rhizotoni, soyens, silion, Trihoerm 3

4 Introution Soyens (Glyine mx L. Merrill) re legumes tht re ntive to Est Asi n hve een use for thousns of yers s high protein foo soure. Vrious Trihoerm spp. hve een reporte to effetively ontrol severl plnt pthogens (Koh, 1999; Zhng et l., 1999). Finings y Koh (1999) n Lewis & Lumsen (2001) emonstrte tht Trihoerm spp. formultions were le to effetively reue mping-off use y Rhizotoni on pes n uumer. Rhizotoni solni n Pythium use reue see germintion n mping off of mny rops n infet seelings or the tips of roots elonging to oler plnts (Henrix & Cmpell, 1973). Rhizotoni uses muh higher iniene of mping-off thn Pythium n hs the ility to use stem n root rot whih my result in pthy growth s well s yiel losses in mny rops. Silion n t s omponent in plnt resistne ginst ioti stress e.g. nutrient toxiities, rought, ol n ioti stresses, e.g. fungi, nemtoes n pests (Epstein, 1999). This enhne resistne is ssoite with higher eposit of silion in the lef whih forms physil rrier to impee pthogen penetrtion n the tivtion of host efene responses (Kim et l., 2002;.Kunzheng et l., 2009). Silion hs een seen to help with Diporthe phseolorum (Cooke & Ellis) (soyen stem nker) s resistne ourre in soyens with the ition of lium silite (Julitti et l., 1996). The im of this tril ws to etermine whether Si n Trihoerm (in the ommeril form of Eo-T ), pplie iniviully or in omintion, hve growth promotion properties n if they re le to ontrol Rhizotoni n Pythium on soyens. 4

5 Mteril n methos Sees & see tretments Soyen sees (v. LS 6161RR) use for oth the growth promotion n the iologil ontrol stuies, were otine from Link Sees (Pty) Lt, P.O. Box 755, Greytown, 3250, KwZulu-Ntl, South Afri. To ensure hesion of the ioontrol gent, Trihoerm (Eo-T ) onto the see, 1.5 g of Gumgr stiker suspension ws ple in 1 L of wter n stirre for pproximtely 1 hr. Of this solution, 0.5 ml ws remove n poure over 76 g of soyen sees, onto whih pproximtely 0.12 g of the ommeril strin of T. hrzinum (Eo-T ) ws e. The trete sees were ir rie on lmin flow enh for 18 hrs. Growth promotion stuies Pot trils Soyen sees were plnte in 15 m imeter pots n fille with sterile omposte pine rk. To ensure the soil ws thoroughly wet, pots were wtere efore n fter plnting. Five tretments were use (Tle 1). Potssium hyroxie (KOH) ws pplie s ontrol euse silion (Si) ws use in the form of potssium silite. Potssium hlorie (KCl) ws e to the Si solution to lne the potssium ions n the ph. Pots were ple in 2 L plsti ontiners tht ontine the tretments, n trnsferre to greenhouse mintine t 22 C, with no overhe irrigtion system. Pots were ple in omplete rnomise lok esign, eh tretment hving four replites with four plnts per replite. Tretments were ple in the plsti ontiners three times week, together with NPK solule fertiliser [3:1:3(38) omplete]. 5

6 After 5 weeks, eril prts of the seelings were ut t soil level, ple in rown pper gs n rie t 70 C in n oven for 48 hrs (Lote, Moel numer 385, South Afri) in orer to etermine the totl ry mss of the seelings. Rhizotron trils Rhizotrons were onstrute from two plexiglss (100 x 150 mm) pltes tht were seprte y silion tue sper (15 mm) n hel together with utterfly nuts n fille with perlite. Sees were trete s esrie for the pot trils. Rhizotrons were overe with luminium foil in orer to prevent ylight from rehing the roots of the seelings, ut the tops were kept open for seeling emergene. Rhizotrons were left in glsshouse mintine t 22 C for 3 weeks. () Root re n root length Seeling roots were hrveste t the soil surfe n finely spre onto white pper n snne into omputer. The imges were pture n the verges of three root re n length mesurements were tken per smple n the men reore using Assess 2.0 (Anonymous, 2008). () Root ry iomss Roots were rie t 70 C for 48 hrs in n oven (Lote, Moel numer 385, South Afri) n their ry weight etermine. 6

7 Control of Rhizotoni n Pythium using silion n Eo-T Growth n preprtion of Rhizotoni n Pythium Rhizotoni n Pythium were su-ulture onto potto extrose gr (PDA) n store t 25 C. Brley sees were soke overnight in istille wter in 500 ml Erlenmeyer flsks, rine n utolve t 121 C for 15 min on two onseutive ys. Three squres (4 mm x 4 mm) of gr inoulte with either Rhizotoni or Pythium were ut n ple onto the sees. Flsks were inute t 25 C until the sees were fully olonise. Inoultion An inoulte Rhizotoni rley see ws ple next to iniviul soyen sees while one Pythium inoulte rley see ws ple 2 m elow eh soyen see. Pot trils Pot trils were the sme s esrie for the growth promotion trils. Tretments use re liste in Tle 2. Rhizotron trils Rhizotron trils were the sme s esrie for the growth promotion trils. Tretments use re liste in Tle 2. Sttistil nlyses All trils were repete n results nlyse using Genstt, 11 th eition (Anonymous, 2008). 7

8 Results Pot trils There ws signifint inrese in ry weight of the Si n Eo-T omintion, followe y iniviul pplitions of Si n Eo-T, i.e., g, g n g, respetively. The un-inoulte ontrol n KOH tretments h the lowest iomss, g n g, respetively (Figure 1). Similr results were seen in the Rhizotoni n Pythium trils, where the omintion of Si n Eo-T proue the highest iomss, g n g, respetively, n the inoulte ontrol proue the lowest iomss, 7.45 g n 9.09 g, respetively. The KOH ontrol h lower ry weight thn the Si tretments for the growth promotion s well s the Rhizotoni n Pythium trils (Figure 1). Rhizotron trils () Root re n root length Si plus Eo-T proue the gretest root re in the growth promotion trils, m 2, while the ontrol h the smllest root re, 7.32 m 2 (Figure 2). The sme pttern ws seen for oth the Rhizotoni n Pythium trils where Si plus Eo-T proue the highest root re, 8.98 m 2 n 9.77 m 2, respetively. The lowest root res were seen for the inoulte ontrol of Rhizotoni (5.05 m 2 ) n Pythium (5.74 m 2 ) (Figure 2). Silion plus Eo-T resulte in the highest root lengths in the growth promotion tril, s well s in the Rhizotoni n Pythium trils with lengths of m, m n m, respetively (Figure 3). There were no sttistilly signifint ifferenes etween ny of the other tretments in the growth promotion tril. The KOH tretment i not show ny sttistilly ifferent results from the Si 8

9 tretment for the Rhizotoni tril n resulte in lower root res n lengths for the Pythium tril. () Root iomss In the growth promotion tril, the pplition of Si plus Eo-T proue the highest iomss, 0.22 g n the Rhizotoni n Pythium trils h sttistilly higher iomss, thn the inoulte ontrols whih h the lowest iomss, g n g, respetively (Figure 4). The KOH tretments were either sttistilly the sme or lower thn the Si plus Eo-T tretments in oth the growth promotion n Rhizotoni n Pythium trils (Figure 4). Disussion The min ojetive of this tril ws to investigte whether Si n Trihoerm, s iniviul tretments or in omintion, h growth promotion properties s well s whether they oul ontrol Rhizotoni n Pythium on soyens. When Si plus Eo- T were pplie, the highest shoot iomss, root re, root length n root iomss were otine. This tril showe tht Si plus Eo-T hve the potentil to reue mping-off n stunting use y Rhizotoni n Pythium. This tretment ws more effetive thn when Si n Eo-T were pplie s iniviul tretments. The iniviul pplition of Si h greter effet on growth promotion n ontrol of Rhizotoni n Pythium when ompre to the KOH tretment, showing tht Si use the effet n not the potssium. Different mehnisms of tion of Si n Trihoerm my explin why the omintion promote plnt growth s well s the ontrol of Rhizotoni n 9

10 Pythium. Silion s mehnism of tion is result of oth physil n physiologil mens. It n e eposite into the epierml lyer of plnt ells, forming mehnil rrier ginst pthogen penetrtion (Kim et l., 2002). It hs lso een shown to ply prt in plnt resistne to oth ioti n ioti stresses (M & Ymji, 2006; Keeping & Kvers, 2008). Smuels et l. (1991) n Mrshner (1995) showe tht Si is le to lter signls in the host n tivtes the plnt efene mehnisms muh fster n more extensively. Trihoerm hs wie rnge of pplitions ue to its vrious ntgonisti mehnisms to pthogens (El, 2000). Trihoerm spp. hve een reporte to effetively ontrol severl plnt pthogens (Koh, 1999; Zhng et l., 1999). The results from the iologil ontrol trils in this stuy supporte the finings of Koh (1999), Lewis & Lumsen (2001) n Tronsmo & Hjeljor, (1998) tht Trihoerm spp. formultions re le to effetively reue mping-off of Rhizotoni s well s t s growth promoter. Silion plus Trihoerm, in the ommeril form of Eo-T, were le to inrese root re, root length n root iomss s well s shoot iomss of the soyen plnts tht were infete with Rhizotoni n Pythium, s well s enhne plnt growth in the sene of either pthogen. This tril ws lso onute on nol n lupins. Silion (200 mg l -1 ) in omintion with Eo-T one gin proue the highest shoot iomss, root re, root length n root iomss (unpulishe results). Fiel trils re neee to lulte the effetiveness of Trihoerm n Si for growth promotion n ontrol of Rhizotoni n Pythium on soyens to help inrese yiels. 10

11 Referenes ANONYMOUS, Assess 2.0. Imge nlysis softwre for plnt isese quntifition. APS Press, Minnesot, USA. ANONYMOUS, Genstt, 11th en. VSN Interntionl. Oxfor, UK. ELAD, Y., Biologil ontrol of folir pthogens y mens of Trihoerm hrzinum n potentil moe of tion. Crop Prot. 19, EPSTEIN, E., Silion. Annu. Rev. Plnt Phys. 50, HENDRIX, F.F. & CAMPBELL, W.A., Pythium s plnt pthogens. Annu. Rev. Phytopthol. 11, JULIATTI, F.C., RODRIGUES, F.A., KORNDÖRFER, G.A., SILVA, O.A. & PEIXOTO, J.R., Effet of silion in resistne inution ginst Diporthe phseolorum f.spp. meriionlis in soyen ultivrs with ifferent resistne levels (Efeito o sil ıio n inu o e resistˆeni Diporthe phseolorum f.spp. meriionlis em ultivres e soj om iferentes n ıveis e resistˆeni). Fitoptol. rs. 21, 26. KEEPING, M.G. & KVEDARAS, O.L., Silion s plnt efense ginst inset herivory: Response to Mssey, Ennos n Hrtley. J..Anim. Eol. 77, KIM, S.G., KIM, K.W., PARK, E.W. & CHOI, D., Silion-inue ell wll fortifition of rie leves: possile ellulr mehnism of enhne host resistne to lst. Phytopthology 92, KOCH, E Evlution of ommeril prouts for miroil ontrol of soilorne plnt iseses. Crop Si. 18, KUNZHENG, K., GAO, D., CHEN, J. & LUO, S., Proing the mehnisms of silion-meite pthogen resistne. Plnt Signl. Behv. 4,

12 LEWIS, J.A. & LUMSDEN, R.D., Bioontrol of mping-off of greenhousegrown rops use y Rhizotoni solni with formultion of Trihoerm spp. Crop Prot. 20, MA, J.F. & YAMAJI, N., Silion uptke n umultion in higher plnts. Trens Plnt Si. 11, MARSCHNER, H., Minerl nutrition of higher plnts, 2n en, Aemi Press, New York, USA. PODILE, A.R. & PRAKASH, A.P., Lysis n iologil ontrol of Aspergillus niger y Billus sutilis AF1. Cn. J.Miroiol.42, SAMUELS, L.A.D., GLASS, M., EBRET, D.L. & MENZIES, G.J., Moility n eposition of silion in uumer-plnts. Plnt Cell Environ. 14, TRONSMO, A. & HJELJORD, L.G., Biologil ontrol of Trihoerm spp. In: G.S. Boln n L.D. Kuykenll (es.). Plnt miroe intertions n iologil ontrol. Mrel Dekker, New York, USA. ZHANG, J.X., BRUTON, B.D., HOWELL, C.R. & MILLER, M.E., Potentil of Trihoerm virens for ioontrol of root rot n vine eline in Cuumis melo L. use y Monosporsus nnonllus. Sutrop. Plnt Si. 51,

13 Tles Tle 1 Tretments use to etermine growth promotion of soyens Tretments 200 mg l -1 Si Eo-T 200 mg l -1 Si n Eo-T Control KOH Si silion Eo-T - Trihoerm hrzinum KOH Potssium hyroxie 13

14 Tle 2 Tretments use to etermine the effet of silion n Trihoerm (Eo-T ) on soyen infete with Rhizotoni n Pythium Tretments 200 mg l -1 Si n Rhizotoni/Pythium Eo-T n Rhizotoni/Pythium 200 mg l -1 Si n Eo-T n Rhizotoni/Pythium Rhizotoni/Pythium (inoulte ontrol) KOH n Rhizotoni/Pythium Un-inoulte ontrol Si silion Eo-T - Trihoerm hrzinum KOH Potssium hyroxie 14

15 List of Figures Figure 1 Dry shoot iomss of five week ol soyen seelings fter pplition of six tretments. Mens followe y ifferent letters re signifintly ifferent t P Figure 2 Root re of three week ol soyen seelings fter the pplition of six tretments. Mens followe y ifferent letters re signifintly ifferent t P Figure 3 Root length of three week ol soyen seelings fter the pplition of six tretments. Mens followe y ifferent letters re signifintly ifferent t P Figure 4 Dry root iomss of three week ol soyen seelings fter the pplition of six tretments. Mens followe y ifferent letters re signifintly ifferent t P

16 Figures Growth promotion Rhizotoni Pythium Dry eril iomss (g) Si Eo-T Si n Eo-T Inoulte ontrol Un-inoulte ontrol KOH Tretments Figure 1. 16

17 Growth Promotion Rhizotoni Pythium Root re (m 2 ) Si Eo-T Si n Eo-T Inoulte ontrol Un-inoulte ontrol KOH Tretments Figure 2. 17

18 Growth promotion Rhizotoni Pythium Root length (m) Si Eo-T Si n Eo-T Inoulte ontrol Un-inoulte ontrol KOH Tretments Figure 3. 18

19 Growth promotion Rhizotoni Pythium Dry root iomss (g) Si Eo-T Si n Eo-T Inoulte ontrol Un-inoulte ontrol KOH Tretments Figure 4. 19