Study On Distinctions Of Pesticides Resistance And Its Physiology Biochemistry In Different Populations Of Pomacea Canaliculata

This paper studied resistance to 4 pesticides(niclosamide,emamectin benzoate,fentin acetate, metaldehyde) in 10 different populations of Pomacea Canaliculata collected from Guangxi,Hainan,Guangdong,Hunan Province.In addition,the seasonal changes of 4 pesticides resistance were studied in Anji County,Nanning city.Guangxi Province.And preliminary explored the relationship between activities of AChE,MFO,EST,GSTs and Cellulolytic Enzymes and resistance to 4 pesticides of Pomacea Canaliculata.These were provideded the foundation for 4 pesticides resistance risk assessment and its mechanisms in Pomacea Canaliculata,it also laid the basis for scientific and rational using molluscicide.The main results were shown as follows:1,With immersion method,the toxicity of 4 pesticides to 10 populations of Pomacea Canaliculata were tested during 2009 and 2010.The monitoring results of two years reflected the resistance level in different geographical populations of Pomacea Canaliculata existed significant difference and changed yearly in a same population.To niclosamide.the resistance level is in turn of Liuyang population. Hengxian population.Anji population,Dongxing population,Danzhou population,Guilin population, Cenxi population,Rongan population.Baise population,Zhuhai population, among which Zhuhai population performanced a most sensitive to niclosamide.its LC50 was 0.2930 mg/L in 2009.and Liuyang population had the topmost resistance level.its resistance ratio was 3.68 times as high as Zhuhai population.To emamectin benzoate,the resistance level is in turn of Danzhou population.Anji population.Liuyang population.Hengxian population. Zhuhai population,Rongan population.Dongxing population,Cenxi population.Guilin population,Baise population,among which Baise population performanced a most sensitive to emamectin benzoate,its LC50 was 0.0920mg/L in 2009.and Danzhou population had the topmost resistance level, its resistance ratio was 4.81 times as high as Baise population.To fentin acetate.the resistance level is in turn of Danzhou population.Liuyang population, Anji population.Guilin population,Cenxi population. Hengxian population.Dongxing population,Rongan population,Baise population,among which Baise population performanced a most sensitive to fentin acetate,its LC50 was 0.2543mg/L in 2009,and Danzhou population had the topmost resistance level, its resistance ratio was 6.43 times as high as Baise population.To metaldehyde.the resistance level is in turn of Anji population, Liuyang population,Danzhou population.Cenxi population.Rongan population.Hengxian population,Guilin population,Dongxing population,Baise population,among which Baise population performanced a most sensitive to metaldehyde.its LC50 was 0.4573mg/L in 2009,and Anji population had the topmost resistance level,its resistance ratio was 4.26 times as high as Baise population.2,The sensitivity of Pomacea Canaliculata (from Anji county.Nanning city) to 4 pesticides was tested in different seasons of years.the results indicated Pomacea Canaliculata in different seasons had different sensitivity to the same pesticide.To niclosamide,the order of sensitivity of Pomacea Canaliculata in different seasons was spring>summer>autumn>winter,among which LC50 was 0.7026mg/L in spring and 0.9322 mg/L in winter; The sensitivity of a same seasons have not obvious difference between different years.To emamectin benzoate.the order of sensitivity of Pomacea Canaliculata in different seasons was summer>autumn>spring>winter,among which LC50 was 0.2019mg/L in summer and 0.7966mg/L in winter.The sensitivity of a same seasons are difference between different years.In spring and Winter,Pomacea Canaliculata were quite insensitive to fentin acetate and metaldehyde,the mortality rate of Pomacea Canaliculata is less than 3% after coped with a maximum solubility concentration of these 2 peslicides,however,in summer or autumn,the result of LC50 was 0.7003～0.7431mg/L to fentin acetate. 1.9489～1.9868mg/L to metaldehyde. whose toxieity were at least 10 times bigger than tested in spring or winter.The main reason for sensitivity differences of seasons was that the temperature influenced the feeding activity and physiological metabolism of Pomacea Canaliculata.3,The activity of AChE,MFO,EST,GSTs and Cellulolytic Enzymes were tested in 9 populations of Pomacea Canaliculata.The results indicated each kind of enzyme had different activity in different populations,and the variation trend of enzymes' activity were not always consistent with the sensitivity to 4 pesticide.Specifically,it was presented a positive association between AChE and LC50 value of 4 pesticides,especially the correlation coefficient between AChE and LC50 value of metaldehyde reached 0.9165.got a extreme significant level.and AChE and LC50 value of fentin acetate reached 0.7687.got a significant level; However,it was presented a negative association between Cellulolytic Enzymes and LC50 value of 4 pesticides,especially the correlation coefficient between Cellulolytic Enzymes and LC50 value of niclosamide reached 0.8741,also got a extreme-significant level; There existed a rather weak correlation between MFO,EST,GSTs and LC50 value of 4 pesticides.