Res. Plant Dis. 15(3) : 187-192 (2009) Research in Plant Disease The Korean Society of Plant Pathology š ƒ ³ (Leveillula taurica) p ½ x*á wá Áw Áw Áy y p w p y Effect of Temperature, Relative Humidity on Germination and Development of Powdery Mildew (Leveillula taurica) on Pepper and Its Inoculation Method Dae-Hyun Kim*, Jong-Han Park, Jung-Sup Lee, Kyung-Sook Han, You-Kyoung Han and Jeong-Hwan Hwang Horticultural & Herbal Crop Environment Division, National Institute of Horticultural & Herbal Science, RDA, Suwon 441-440, Korea (Received on November 10, 2009; Accepted on December 7, 2009) Pepper powdery mildew, Leveillula taurica is one of the most important pathogens of pepper in the greenhouses and fields in Korea and is becoming a worldwide disease. These experiments were carried out to investigate the optimal germination, disease development conditions, disease incidence and effective inoculation methods of pepper powdery mildew. The incidence of powdery mildew was investigated throughout the country based on the major pepper growing areas in 2009. The average rate of infected leaves ranged from 15.3% to 81.8% in greenhouses and fields. Powdery mildew incidences were more severe in greenhouses than those of fields. The optimal temperature for conidial germination was 25 o C and showed the highest germination at 6 hs after treatment. The range of temperature for germination was 10 o C to 35 o C. Temperature of greater than 30 o C and below 20 o C affected the abnormal germination and germ tube elongation. The optimal relative humidity for germination and germ tube elongation was 85% and germination increased as relative humidity increased. Disease development started 8 days after inoculation and showed the highest disease severity at 15 days in greenhouse and field regardless of varieties. Among three different inoculation methods tested the spore dropping method was better than touching with infected leaves and spraying with spore suspension. However, the method has limitation in mass inoculation due to the amount of time consumed. Keywords : Disease incidence, Germination, Germ tube, Leveilula taurica, Pepper, Powdery mildew ù š w ƒ 1980 š z ƒwš, p ƒ ƒ (, 2001;, 2003;, 1980). t t» ³ ƒ w» ƒ q y k š Ÿw z (Correll, 1986; Heffer, 2006). w š š w (, 1980). Correll (1987) Dik (1999) ƒ *Corresponding author Phone) +82-31-290-6134, Fax) +82-31-290-6290 Email) kimdh823@rda.go.kr w ƒ ù, ƒ y y vw š š w. š ƒ ³ Leveillula taurica ³ û³ w y» ³ ûs s x w š ù, ü û w w (, 1980). L. taurica Oidiopsis taurica w, t w w w («, 1998; Beris Hormattallah, 1985; Diop-Bruckler, 1989). w š û» ƒ j ƒ w (, 2008), š m m, ƒ, j» w j vw š (, 1995; «, 1998; Heffer, 2006).
188 ½ xá wá Áw Áw Áy y š ƒ ƒwš ùyƒ ƒ y vwƒ ƒwš (Elad, 2007). ù p y» ³ œ (Correll, 1987; Elad, 2007) yw k w ƒ w. p vw k š s, z ³ y w w t w v w. ¾ š ƒ w vw, ü ³ e» (Celio, 1998),» (microclimate) ³ e w(elad, 2007), ƒ ƒ e w(remigio, 2003) š ƒ ³ w w ƒ š. š ƒ w k y w w š w y w ƒ w š t w y g ww.. 2009 4 9,, û û 4 ƒ xy v w w. 4 š w û,,, w, 9 z,,, û, w û w w. œ ³ ³. p w xs w ü š w sw š ƒ ³ q w š w ³ œ ³ w. s. s ³ w v p» 85% w z, s slide grass 10, 15, 20, 25, 30, 35 C o 3, 6, 9, 21 w k z, s x 100 w. s 25 C š w o z, 55, 70, 85, 93, 100% w z 6 z s x 100 w. ¼ 20 s k w s ¼ Dpx view pro ful v w w. œ t. z w» w š (t : Ÿ,,, wm, ¼ ) 5ƒ œ t w, œ y, 2t œ w xw. w t 8 3 q w, 45 z 9 16 ( 10 ü ) š ƒ sp x w.. ³ s z, ³ x kw s 2 10 /mlü w 5 15 ü š w. w ³» w 3 z x g. š s w z g. k ³ ù ³ x g. ³ x w (, 15~35 o C, RH 40~70%), w (, 27±2 o C, RH 40±10%) z» w.. ü ƒ =( / 100) w. š œ x w w. 0-4 ¾ ù, 0=, 1= 1~5%, 2=5.1~20%, 3=20.1~40%, 4=40.1% w w. s³ w Duncan's multiple range test(dmrt, P=0.05) w. š vw. 2009 4 9,, û û 4 ƒ w, 15.3% 81.8%¾ 6CDNGTtqpu qg qu iupq iq r.gxgknnwncvcwtkec r q q u tqygv q q s u sg qg F ig u Ttq g q ru rqi qpxqgˆq C 8g q A qq t q @uqxp B q s q s 'Sq $%""$ '#!$"!!!% W v 'Sq &&%' &# %!% %# 9 y q s 'Sq #&$ ' &' ""!" $ Gux g s 5! $ &!% 7tg s q s 5!&'! "! 7tg s 5 #!! ' Du v 5!$ ' "" "%% %& Bgp s 'Sq #'## $! Yq sgy 'Sq %%"#' ' $& # a The rates of infected leaves (%)=No. of infected leaves/total number of leaves 100.
š ƒ ³(Leveillula taurica) p 189 (KI 8u qg q y y r tq q q pq yuxpq.gxgknnwnc VCWTKEC sq yu g u s i upug g p i upu t q #( Sqˆq qx pq yuxpq u rqi qp q q xg $(7 upugxsq yu g u %(7 upu t q &(Yqxx xqgr rgiq'(p pq yuxpq xqgr pq rgiq((c rqi qpxqgˆq hqigyqp u s w (Table 1). xk 15.3~81.8%(s³ 71%), 16.8~ 72.3%(s³ 46%) š ƒ. ƒ w ƒ 100% ƒ¾ ù kü š, w» 2~3 sw ƒ 10% ùkü ƒ w. ƒ ƒ s ƒ r š, ù ù y k š Ÿw z g (Fig. 1A, D, E, F).. š ƒ s w (Table 2), w w 6 z 6CDNG 9rrqi r qy q g q sq yu g u r.gxgknnwnc VCWTKECi upug sxg xupq u i hg qpr!$' t g &# qxg uˆqt yupu Tqy q g q Aq yu g u \ Q 7!t $t 't t p!p &q g # p #!p p "h i ''i &&i $%gh # #!g!#'g!# g 'g! $!h!&h!&h $!gh!#!p!p $r $i z Values followed by the same letter in the column are not significantly different at P=0.05 according to Duncan's multiple range test. š 25 o C 35.9% ƒ. w 85% 38.5% ƒ (Table 4). ¼ d w Table 3 w 20~25 o C 105.8~107.7 µm ƒ ¼, d w, 85~93% 79.7~80.3 µm ƒ ¼ (Table 4). š ƒ s x ƒ (25 o C, RH 85%) ¼ ƒ ¼ s ¼ ùkü. (1980) š ƒ ³ s x 25 o C, 100% ƒ š w ü w ù, 6CDNG9rrqi r qy q g q sq y hq r.gxgknnwncvcwtkec i upug sxg xupq u i hg qpr $t g &# qxg uˆqt yupu Fq s t Tqy q g q Q 7 µm # #! Aq y hq '& %% %% #& %$ 6CDNG 9rrqi r qxg uˆq t yupu RB sq yu g u g p sq y hq r.gxgknnwncvcwtkeci upug sxg xupq u i hg qp r $tg # Q 7g pg purrq q RBxqˆqx Rqxg uˆq t yupu ## % &# '! Aq yu g u \ $i $!hi!&#g ''h '#hi Aq y hqµm $ $' &! %'% $$& z Values followed by the same letter in the row are not significantly different at P=0.05 according to Duncan's multiple range test.
190 ½ xá wá Áw Áw Áy y ùkü. ƒ 20~30 o C ƒ s» w š w. Elad (2007) š (sweet pepper) ƒ s x s 6 w z d w, 20 o C 20% ƒ š, 85% ƒ ùkü ü w. w š ƒ w (, 1997;, 1980), s x (85~93%) y. š Reuveni Rotem(1973) ƒ s ƒ w ƒ 25 o C, ƒ 25 o C š ¼ ƒ š šw. š û (Perera Wheeler, 1975), 100% w s ƒ š, s w w š š w (Remigio, 2003). z. Ÿ,,, wm, ¼ š ƒ k z» w t ƒ, z 8 ¾ 3~7%, 12 z 10% ƒ 15 z 53.3~73% w ƒw (Fig. 2). ³ p e w ùkü š 15». (1997) ³ ƒ e w 6 z xw, 10~12 z w š w. Homma (1981) ³ e z ü ³ w» 3~4 š, ³ ƒ»œ (KI8u qg q qˆq u r q q i x uˆg g & #'pg gr q u i xg u u t.gxgknnwncvcwtkecu s qq t qg pruqxpc A qq t q qy q g q#!# Q 75(H ww g s6(wg spgqhgw7(6 it D@uqxp qy q g q'' &# Q 75(7tq tg sux 6(Aux g s C Vgx q r xx qph tq gyqxq q g q us uruig x purrq q g 21#gii pu s 8 ig y x u xq g sq q D 9 hg g q g pg pq (KI8u qg q qˆq u r q q i x uˆg u gii pu s tqpurrq q u i xg u yq t p i upugx q u g itu s u t u rqi qpxqgˆq p u s tq q u s qq t qg ps t y #Ii hq q qi uˆqx CAB(A qq t q qy q g q #!# Q 7RB" %DA7(A titgyhq qy q g q %± Q 7RB"± C Vgx q r xx qph tq gyqxq q g q us ur uig x purrq q g 21#gii pu s 8 ig y x u xq g sq q D 9 hg g q g pg pq
š ƒ ³(Leveillula taurica) p 191 (KISt u spu qg q qˆq u r tqxqgˆq y y gr q purrq q g uruiugxu i xg u #(7 upugx q u g $(T itu s u rqi qpxqgˆq %(8 u s tq q s mw w w s š w» y. š (15-35 C) o (9.9-28.5 C) o x y ww. z. š ƒ œ w» w, k w Fig. 3. k ùkü, p k w œ 72% ƒ ùkü w w œ w w (Fig. 4A, B, C). wé w» w z ù, š ƒ w p (, 1997;, 1980) w wš w x v w š q. š ƒ x (Elad, 2007; Souza Cafe-Filho, 2003), k (, 2001;, 2003; Homma, 1980; Homma, 1981; Reuveni, 1998; Remigio, 2003; Souza Cafe-Filho, 2003) wš ù, ü ¾ xk w ww. Souza Cafe-Filho(2003) leveillula taurica š ƒ w w s xk (5 10 /ml) w 4 w š, Elad (2007) š ƒ w» z» w ³ 1 10 /ml z 10~15 ü 6 w š šw. ù x š ƒ œ w k w xwš. y. x w y (w, 27±2 o C, RH 40±10%) (, 15~35 o C, RH 40~70%) ùkü (Fig. 3), w. û» ƒ w ƒ š ƒ w ew š ƒw. Agrios (1998) t ƒ w s û š, ƒ û (50~70%) w š w. w (1980) š ƒ û š w ù, Elad (2007) ƒ w (15~20 o C) û (85~95%) w y k š w, û 30 o C w š û w š w w. ¾ ww ¾ y š ƒ w yw e x š (Elad, 2007), w s ƒ v w š ƒ. š w ƒ ùš, p ƒ ƒ wù. 2009 4 9,, û û 4 ƒ k w. 15.3~81.8%(s³ 71%), 16.8~72.3%(s³ 46%). ƒ w s ƒ r š, y k ù ù. š ƒ s w, 25 o C z 6 35.9%, 85% 38.5% ƒ. d w, 20~25 o C 85~93% ƒƒ 105.8~107.8 µm 79.7~80.3 µm ƒ ¼ ùkû. š ƒ k z w z 8 l ƒ, 15 z ƒ 53.3~73% w. š ƒ
192 ½ xá wá Áw Áw Áy y œ w» w, k w, k ùkü. p k w œ ƒ 72% ƒ ùk ü w w w w ù, z š w z v w. š x Agrios, G. N. 1998. Plant pathology (4th edition). Academic press, Inc., New York. pp. 147-148. Beris, M. and Hormattallah, A. 1985. Manifestation et mode de conservation de Leveillula taurica, Agent de I'Oidium de la Tomato au Maroc. Phytopath. Z. 112: 348-354. Celio, G. J. and Hausbeck, M. K. 1998. Conidial germination, infection structure formation, and early colony development of powdery mildew on poinsettia. Phytopathology 88: 105-113.,», y, ½». 1980. š w ƒ. w y 19: 241-243. Correll, J. C. 1986. The epidemiology of tomato powdery mildew (Leveillula taurica) in relation to host growth and development. Ph. D. Dissertation, University of California, Berkely. 143 pp. Correll, J. C., Gordon, T. R. and Elliott, V. J. 1987. Host range, specificity, and biometrical measurements of Leveillula taurica In california. Plant Dis. 71: 248-251. Dik, J. A., Ceglarska, E. and Ilovai, Z. 1999. Sweet Peppers. 473-485 pp. in: Integrated Pest and Disease Management in Greenhouse Crops. Kluwer Academic Publishers, Dordrecht, the Netherlands. Diop-Bruckler, M. 1989. Development de Leveillula taurica en fonction des facteurs climatiques et sensibilite de Capsicum annuum a differents stades vegetatifs. J. Phytopathology 126: 104-114. Elad, Y., Messika, Y., Brand, M., Rav D. D. and Sztejnberg, A. 2007. Effect of microclimate on Leveillula taurica powdery mildew of sweet pepper. Phytopathology 97: 813-824. Heffer, V., Johnson, K. B., Powelson, M. L. and Shishkoff, N. 2006. Identification of powdery mildew fungi. The Plant Health Instructor. DOI: 10.1094/PHI-I-2006-0706-01. Homma, Y., Arimoto, Y., Takahashi, H., Ishikawa, T., Matsuda, I. and Misato, T. 1980. Studies on pepper powdery mildew I. Conidial germination, hyphal elongation and hyphal penetration on pepper leaf. Ann Phytopath. Soc. Japan 46: 140-149. Homma, Y., Takahashi, H., Arimoto, Y., Ishikawa, T., Matsuda, I. and Misato, T. 1981. Studies on pepper powdery mildew. Conidiophore emergence and conidial formation on pepper leaf. Ann. Phytopath. Soc. Japan 47: 143-150., «x,, ½ ³. 1995. Oidiopsis taurica(lev.) Arnaud(=Leveillula taurica) w m m ƒ. w wz 11: 380-382. «x,,, ½ ³. 1998. Leveillula taurica Arnaud w ƒ ƒ. w wz 14: 186-187., y k, x,. 2003. š ƒ. 2003 x š., y, ½, w x,, ½. 2001. š ƒ w w k. w» 19: 7-11.. 1997. w. 447 pp. Perera, R. G. and Wheeler, B. E. 1975. Effects of water on the development of Sphaerotheca pannosa on rose leaves. Trans. Br. Mycol. Soc. 64: 313-317. Remigio, A. Guzman-Plazolaa, Michael D. R. and James J. M. 2003. Effects of relative humidity and high temperature on spore germination and development of tomato powdery mildew (Leveillula taurica). Crop Protection 22: 1157-1168. Reuveni, R., Dor, G. and Reuveni, M. 1998. Local and systemic control of powdery mildew (Leveillula taurica) on pepper plants by foliar spray of mono-potassium phosphate. Crop Protection 17: 703-709. Reuveni, R. and Rotem, J. 1973. Epidemics of Leveillula taurica on tomatoes and peppers as affected by the conditions of humidity. Phytopathol. Z. 76: 153-157. Souza, V. L. D. and Cafe-Filho, A. C. 2003. Resistance to Leveillula taurica in the genus Capsicum. Plant Pathology 52: 613-619. s, x,, ½ z. 2008. w ( ). 388 pp.