, 2005, 7 (3) : 2372241 Chinese Journal of Pesticide Science 1, 1, 13, 2, 2 (1., 100094; 2., 100026) : 2003 2004 127 Phytoph thora infestans, : 2003 2003 2004 (MS) 86. 2% 13. 8% 17. 8% ; 10,, EC 50 0. 10 0. 35 g/ml, EC 50 0. 20 ( 0. 06) g/ml,, ;,, : ; ; ; ; : S481. 4 : A : 100827303 (2005) 0320237205 D etection on the Sen sitiv ity of Pota to Phytoph thora infestans to M eta laxyl and Cym oxan il YUAN Shan2kui 1, ZHAO Zhi2hua 1, L IU Xi2li 13, L IU L iang 2, J IANG Hui 2 (1. D epartm ent of P lant Pathology, College of A gronom y and B iotechnology, China A gricultural U niversity, B eijing 100094, China; 2. Center of A grochem icals for B iological and Environm ental Technology, Institute for the Control of A grochem icals, M inistry of A griculture, B eijing 100026, China) Abstract: In 2003 and 2004, 127 Phy toph thora infestans isolates were samp led from InnerMongolia and Heilongjiang, China, their sensitivities to metalaxyl and cymoxanil were determ ined in vitro. The results showed that the m etalaxyl2sensitive (M S) isolated in 2003 from InnerMongolia, 2003 and 2004 from Hei2 longjiang, covered 86. 2%, 13. 8% and 17. 8%, respectively. A lthough cymoxanil has been used nearly for 10 years in these areas, but no any decreasing in sensitivity of P. infestans populations has been detec2 ted. Their EC 50 values for cymoxanil ranged from 0. 10 g/ml to 0. 35 g/ml, the mean EC 50 value ( SD ) was 0. 20 ( 0. 06) g/ml exhibited unimodal distribution of sensitivity, which could be used as the baseline2sensitivity for monitoring the field resistance development in the future. There was no cross2 resistance between m etalaxyl and cymoxanil in field populations of P. infestans. Cymoxanil gave equal effect on both metalaxyl2resistant and w ild2sensitive isolates. Key words: Phy toph thora infestans; metalaxyl; cymoxanil; resistance; baseline2sensitivity : 2005202221; : 2005203230. : (19762),,,, ; : 010262731013; E2mail: seedling@ cau. edu. cn :. 3 : ( 19692),,.
238 Vol. 7 Phy toph thora infestans,,, ( Phenylam ide fugicides, PAFs) 1977, 2 3 PAFs, [ 1 ] 1976,,, P lasm opa ra viticola 20 80 PAFs,,, [ 2 ] Zhang 134, 14. 9%, [ 3 ], 20 90, 10 2003 2004, 1 1. 1 ( Rye Sucrose Agar, RSA ), ( 1 000 ml ) : 60 g ( 70 ), 500 ml 25 24 48 h;,, 500 ml 1 2 m in; 60 1 h, 4, ; 15 g 20 g,, 121 25 m in 1. 2 2003, 58 ; 2004 69, 1 km,, 1. 3 98% (metalaxyl) ; 98. 1% ( cymoxanil), 5 000 g/ml, 4 1. 4 g 5 mm, 5 10 100 g/ml ( ) RSA, 3, 19 7 d ( Percent of grow th, PG, % ) ( - 5) PG ( % ) = 100 ( - 5) Shattock [ 4 ] Forbes [ 5 ] ( 1) [ 6 ], EC 50, EC 50, Table 1 Metalaxyl2resistance division criteria published by Shattock (1988) and Forbes(1997) Author Metalaxyl2sensitive,MS Metalaxyl2intermediate,M I Metalaxyl2resistant,MR Shattock 10 g/ml: PG 10% 10 g/ml: 10% < PG < 60% 10 g/ml: PG 60% Forbes 5 g/ml: PG < 40% 5 g/ml: PG 40% 5 g/ml: PG 40% 100 g/ml: PG < 40% 100 g/ml: PG < 40% 100 g/ml: PG 40%
No. 3 : 239 2 2. 1 Shattock Forbes, Shattock M S M I, Forbes M I Shattock M I 5 g/ml 10 g/ml 10%, 40%, Forbes M I ; Shattock MS 5 g/ml 10 g/ml 10%, Forbes MS; MR, 100 g/ml Shattock 2, 2003,, 86. 2% ; 2003 2004,, (M I + MR ) 86. 2% 82. 6%, Years Table 2 Occurrence of metalaxyl2resistant isolates of P1infestans samp led from InnerMongolia and Heilongjiang in 2003 and 2004 3 Number of MS M I M I Provinces isolates Number Frequency( % ) Number Frequency( % ) Number Frequency( % ) 2003 InnerMongolia 29 25 86. 2 1 3. 5 3 10. 3 2003 Heilongjiang 29 4 13. 8 4 13. 8 21 72. 4 2004 Heilongjiang 69 12 17. 4 6 8. 7 51 73. 9 3 According to the standard of Shattock (1988). 2. 2 3,, ;, 2003 2004, Years Table 3 Comparison of the sensitivity to cymoxanil of P. infestans populations samp led from Inner Mongolia and Heilongjiang in 2003 and 2004 Number of EC 50 values for cymoxanil / g ml - 1 Provinces strains Range Means SD 2003 InnerMongolia 29 0. 11 0. 35 0. 21 a 3 0. 06 2003 Heilongjiang 29 0. 10 0. 34 0. 21 a 0. 07 2004 Heilongjiang 69 0. 12 0. 34 0. 19 a 0. 05 3 Significance level with Duncanπs test at P = 0. 05. 127 EC 50 ( 1 ),,, EC 50 0. 10 0. 35 g/ml, 3. 3,,, 127 EC 50 ( 0. 20 0. 06 g/ml ) 2. 3 2,,MS MR EC 50, M I EC 50, MS EC 50 0. 11 0. 35 g /ml, 0. 19 ( 0. 06) g/ml; M I EC 50 0. 13 0. 32 g/ml, 0. 23 ( 0. 06) g/ml; MR EC 50
240 Vol. 7 0. 10 0. 35 g/ml, 0. 21 ( 0. 06) g/ml,, Fig. 1 Sensitivity distribution of field P. populations( n = 127) to cymoxanil infestans Fig. 2 Sensitivity to cymoxanil of P. infestans isolates w ith different sensitivity to metalaxyl 3,, [ 4, 7 9 ], 80% (M I +MR ),,, (oxadixyl) ( furalaxyl) ( benalaxyl), 10, 127 EC 50 0. 20 ( 0. 06 ) g/ml, Ham len, EC 50 0. 19 ( 0. 12) g/ml, 16 [ 10 ] 15 8 11,, 3 [ 11 ] ;, 10 g/ml,,,
No. 3 : 241 ( famoxadone),,,,, [ 13 ],, : [ 1 ] Gisi U. Resistance to phenylam ide fungicides: a case study with Phytoph thora infestans involving mating type and race structure [ J ]. Annu Rev Phytopathol, 1996, 34: 5492572. [ 2 ] L IW ei ( ), ZHANG Zhi2m ing ( ), L I Chuan ( ), et a l. [ J ]. J Hebei A g ric U n iv ( ), 1998, 21 ( 3 ) : 53260. [ 3 ] Zhang Z M, L i Y Q, Zhu J H, et al. Prelim inary study on metalaxyl2resistant isolates of Phytoph thora infestans in China [ A ]. Proceedings of the International Workshop on Potato Late B light. Pyongchang, Ganwon, Korea, 2001. 1012105. [ 4 ] Shattock R C. Studies on the inheritance of resistance to metalaxylin Phytophthora infestans[ J ]. Plant Pathology, 1988, 37: 4211. [ 5 ] Forbes G A. Manual for Laboratory Work on Phytoph thora infestans[m ]. International Potato Center( C IP), 1997. 5216. [ 6 ] YUAN Shan2kui( ), L IU L iang( ), J IANG Hui( ), et a l. 5 [A ]. ZHOU M ing2guo ( ). Chem ical Control of Plant D is2 eases in China ( ) [ C ]. Beijing( ) : China Agriculture Science and Technology Press ( ), 2004. 2122219. [ 7 ] WANG Ying2hua ( ), GUO L i2yun ( ), L IANG De2 lin ( ), et al. [ J ]. J China Agric U niv ( ), 2003, 8 (1) : 78282. [ 8 ] B I Chao2wei ( ), CHE Xing2bi ( ), MA Jin2cheng( ), et al. [ J ]. J Southwest China Agric U niv ( ), 2002, 24 (4) : 3072309, 345. [ 9 ] ZHANG Zhi2m ing ( ), CAO Chen2guang ( ), WANG Hui2sheng( ), et al. ( Phytophthora infestans) [ J ]. China Potato( ), 2004, 18 (5) : 2722273. [ 10 ] Ham len R A, Power R J. D istribution of sensitivity responses to cymoxanil within global populations of Phytophthora infestans[ J ]. Pestic Sci, 1998, 53: 1012103. [ 11 ] WANG W en2qiao ( ), L IU Guo2rong ( ), ZHANG Xiao2feng( ), et al. [ J ]. Acta Phytopathologica S inica ( ), 2000, 30 (1) : 48252. [ 12 ] Ziogas B N, Davidse L C. Studies on the mechanism of action of cymoxanil in Phytophthora infestans[ J ]. Pestic B iochem Physiol, 1987, 29: 89296. [ 13 ] HONG Xi2wu ( ). [ J ]. Pes2 ticide Science and Adm inistration ( ), 1996, 17 (2) : 25226. ( Ed. J IN S H)