[Objective] The research aimed to assess the effect of transgenic Bt plus CpTI cotton variety SGK321 on carboxylesterase and acetylcholinesterase of cotton aphid Aphis gossypii and provide theoretical basis for studyi...[Objective] The research aimed to assess the effect of transgenic Bt plus CpTI cotton variety SGK321 on carboxylesterase and acetylcholinesterase of cotton aphid Aphis gossypii and provide theoretical basis for studying the biosafety of transgenic cotton.[Method] Cotton aphids were fed with SGK321 and Shiyuan321（normal parental varieties） for over 40 generations.Enzyme activities were compared between cotton aphids feeding on SGK321 for 1,2,3,41,42 and 43 generations with those on Shiyuan321.[Result] The carboxylesterase activity of cotton aphids feeding on SGK321 for 1 generation was significantly higher than those feeding on Shiyuan321.Acetylcholinesterase activity of cotton aphids feeding on SGK321 for 1,2 and 3 generations were significantly higher than those feeding on Shiyuan321 in the same generation.But there was no significant difference of enzyme activity between cotton aphids feeding on SGK321 for a long term and those feeding on parental cotton.[Conclusion] The cotton aphid that feeding on transgenic Bt plus CpTI cotton SGK321 for a long time has adaptivity to SGK321 by regulating the detoxifying enzyme.展开更多
Extensive use of insecticides on cotton has prompted resistance development in the cotton aphid, Aphis gossypii （Glover） in China, A deltamethrin-selected population of cotton aphids from Xinjiang Uygur Autonomous R...Extensive use of insecticides on cotton has prompted resistance development in the cotton aphid, Aphis gossypii （Glover） in China, A deltamethrin-selected population of cotton aphids from Xinjiang Uygur Autonomous Region, China with 228,59-fold higher resistance to deltamethrin was used to examine how carboxylesterase conferred resistance to this pyrethroid insecticide. The carboxylesterase activity in the deltamethrin-resistant strain was 3.67-, 2,02- and 1.16-fold of the susceptible strain when using α-naphthyl acetate （α-NA）, β-naphthyl acetate （β-NA） and α-naphthyl butyrate （α-NB） as substrates, respectively, Carboxylesterase cDNA was cloned and sequenced from both deltamethrinresistant and susceptible strains. The cDNA contained 1581 bp open reading frames （ORFs） coding a 526 amino acid protein. Only one amino acid substitution （Val^87-Ala） was observed between deltamethrin-resistant and susceptible strains but it is not genetically linked to resistance by the catalytic triad and signature motif analysis. The real-time polymerase chain reaction analysis indicated that the resistant strain had a 6.61-fold higher level of carboxylesterase mRNA than the susceptible strain. The results revealed that up-regulation of the carboxylesterase gene, not modified gene structure, may be responsible for the development of resistance in cotton aphids to deltamethrin.展开更多
The melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a highly polyphagous sap sucking pest on wide varieties of crops including cotton and vegetables. It is a notorious vector of many plant viruses that a...The melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a highly polyphagous sap sucking pest on wide varieties of crops including cotton and vegetables. It is a notorious vector of many plant viruses that are persistently and non-persistently transmitted. In nature, aphids are regulated by their natural enemies. However, chemical control remains a major management tool even though resistance to insecticides has been documented worldwide. A better understanding of mechanisms by which insecticide resistance occurs and its early detection is desirable to develop effective management strategies. The present investigation was conducted to study the development of resistance to an organophosphate (OP) compound-dimethoate, identify biochemical mechanism(s) involved in resistance and study cross-resistance to imidacloprid in laboratory selected A. gossypii strains in comparison to susceptible strains. Bioassay studies revealed that the LC50 values increased dramatically with dimethoate selection in resistant strains and the resistance ratio (RR) was 270-, 243- and 210-fold greater than that of the susceptible strains by 30th generation. Further, biochemical assays revealed enhanced activities of carboxylesterases (CarE), glutathione S-transferases (GSTs) and cytochrome P450-mediated p-Nitroanisole O-demethylase (PNOD) in resistant strains supporting their role in dimethoate detoxification. This study thus revealed that enhanced activity of detoxifying enzymes viz., CarE, GSTs and PNODs is one of the mechanisms underlying dimethoate resistance in A. gossypii collected from South India. Interestingly, the possibility of negatively correlated cross-resistance to imidacloprid was identified in three OP- resistant strains exhibiting 2.97-, 2.56- and 3.76-fold sensitivity to imidacloprid (a novel neonicotinoid). This indicated that the latter was less affected by the resistance mechanism(s) present.展开更多
The melon aphid, <i>Aphis gossypii</i> Glover (Hemiptera: Aphididae), is a highly polyphagous sap sucking pest on wide varieties of crops including cotton and vegetables. It is a notorious vector of many p...The melon aphid, <i>Aphis gossypii</i> Glover (Hemiptera: Aphididae), is a highly polyphagous sap sucking pest on wide varieties of crops including cotton and vegetables. It is a notorious vector of many plant viruses that are persistently and non-persistently transmitted. In nature, aphids are regulated by their natural enemies. However, chemical control remains a major management tool even though resistance to insecticides has been documented worldwide. A better understanding of mechanisms by which insecticide resistance occurs and its early detection is desirable to develop effective management strategies. The present investigation was conducted to study the development of resistance to an organophosphate (OP) compound-dimethoate, identify biochemical mechanism(s) involved in resistance and study cross-resistance to imidacloprid in laboratory selected <i>A. gossypii</i> strains in comparison to susceptible strains. Bioassay studies revealed that the LC50 values increased dramatically with dimethoate selection in resistant strains and the resistance ratio (RR) was 270-, 243- and 210-fold greater than that of the susceptible strains by 30th generation. Further, biochemical assays revealed enhanced activities of carboxylesterases (CarE), glutathione S-transferases (GSTs) and cytochrome P450-mediated <i>p</i>-Nitroanisole <i>O</i>-demethylase (PNOD) in resistant strains supporting their role in dimethoate detoxification. This study thus revealed that enhanced activity of detoxifying enzymes <i>viz</i>., CarE, GSTs and PNODs is one of the mechanisms underlying dimethoate resistance in <i>A. gossypii</i> collected from South India. Interestingly, the possibility of negatively correlated cross-resistance to imidacloprid was identified in three OP- resistant strains exhibiting 2.97-, 2.56- and 3.76-fold sensitivity to imidacloprid (a novel neonicotinoid). This indicated that the latter was less affected by the resistance mechanism(s) present.展开更多
为筛选出对棉蚜高效的药剂品种,选用了6种杀虫剂对棉花苗期棉蚜进行田间药效评价。试验结果表明:20%氟啶虫酰胺悬浮剂和50 g/L双丙环虫酯可分散液剂对棉蚜的速效性和持效性均较好,药后1 d仿效即可达到>88%,药后14 d防效仍能保持在>...为筛选出对棉蚜高效的药剂品种,选用了6种杀虫剂对棉花苗期棉蚜进行田间药效评价。试验结果表明:20%氟啶虫酰胺悬浮剂和50 g/L双丙环虫酯可分散液剂对棉蚜的速效性和持效性均较好,药后1 d仿效即可达到>88%,药后14 d防效仍能保持在>95%;20%吡虫啉可分散液剂速效性好,但持效性较差,持效期仅有7 d;20%环丙氟虫胺悬浮剂速效性和持效性均表现一般;50%吡蚜酮水分散粒剂对棉蚜防效最差。20%氟啶虫酰胺悬浮剂75 g a.i./hm^(2)、50 g/L双丙环虫酯可分散液剂7.5 g a.i./hm^(2)或12 g a.i./hm^(2)均可有效防治苗期棉蚜。展开更多
基金Supported by Major Program for New Transgenic Plant VarietiesBreeding (2008ZX08012-04)~~
文摘[Objective] The research aimed to assess the effect of transgenic Bt plus CpTI cotton variety SGK321 on carboxylesterase and acetylcholinesterase of cotton aphid Aphis gossypii and provide theoretical basis for studying the biosafety of transgenic cotton.[Method] Cotton aphids were fed with SGK321 and Shiyuan321（normal parental varieties） for over 40 generations.Enzyme activities were compared between cotton aphids feeding on SGK321 for 1,2,3,41,42 and 43 generations with those on Shiyuan321.[Result] The carboxylesterase activity of cotton aphids feeding on SGK321 for 1 generation was significantly higher than those feeding on Shiyuan321.Acetylcholinesterase activity of cotton aphids feeding on SGK321 for 1,2 and 3 generations were significantly higher than those feeding on Shiyuan321 in the same generation.But there was no significant difference of enzyme activity between cotton aphids feeding on SGK321 for a long term and those feeding on parental cotton.[Conclusion] The cotton aphid that feeding on transgenic Bt plus CpTI cotton SGK321 for a long time has adaptivity to SGK321 by regulating the detoxifying enzyme.
文摘Extensive use of insecticides on cotton has prompted resistance development in the cotton aphid, Aphis gossypii （Glover） in China, A deltamethrin-selected population of cotton aphids from Xinjiang Uygur Autonomous Region, China with 228,59-fold higher resistance to deltamethrin was used to examine how carboxylesterase conferred resistance to this pyrethroid insecticide. The carboxylesterase activity in the deltamethrin-resistant strain was 3.67-, 2,02- and 1.16-fold of the susceptible strain when using α-naphthyl acetate （α-NA）, β-naphthyl acetate （β-NA） and α-naphthyl butyrate （α-NB） as substrates, respectively, Carboxylesterase cDNA was cloned and sequenced from both deltamethrinresistant and susceptible strains. The cDNA contained 1581 bp open reading frames （ORFs） coding a 526 amino acid protein. Only one amino acid substitution （Val^87-Ala） was observed between deltamethrin-resistant and susceptible strains but it is not genetically linked to resistance by the catalytic triad and signature motif analysis. The real-time polymerase chain reaction analysis indicated that the resistant strain had a 6.61-fold higher level of carboxylesterase mRNA than the susceptible strain. The results revealed that up-regulation of the carboxylesterase gene, not modified gene structure, may be responsible for the development of resistance in cotton aphids to deltamethrin.
文摘The melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a highly polyphagous sap sucking pest on wide varieties of crops including cotton and vegetables. It is a notorious vector of many plant viruses that are persistently and non-persistently transmitted. In nature, aphids are regulated by their natural enemies. However, chemical control remains a major management tool even though resistance to insecticides has been documented worldwide. A better understanding of mechanisms by which insecticide resistance occurs and its early detection is desirable to develop effective management strategies. The present investigation was conducted to study the development of resistance to an organophosphate (OP) compound-dimethoate, identify biochemical mechanism(s) involved in resistance and study cross-resistance to imidacloprid in laboratory selected A. gossypii strains in comparison to susceptible strains. Bioassay studies revealed that the LC50 values increased dramatically with dimethoate selection in resistant strains and the resistance ratio (RR) was 270-, 243- and 210-fold greater than that of the susceptible strains by 30th generation. Further, biochemical assays revealed enhanced activities of carboxylesterases (CarE), glutathione S-transferases (GSTs) and cytochrome P450-mediated p-Nitroanisole O-demethylase (PNOD) in resistant strains supporting their role in dimethoate detoxification. This study thus revealed that enhanced activity of detoxifying enzymes viz., CarE, GSTs and PNODs is one of the mechanisms underlying dimethoate resistance in A. gossypii collected from South India. Interestingly, the possibility of negatively correlated cross-resistance to imidacloprid was identified in three OP- resistant strains exhibiting 2.97-, 2.56- and 3.76-fold sensitivity to imidacloprid (a novel neonicotinoid). This indicated that the latter was less affected by the resistance mechanism(s) present.
文摘The melon aphid, <i>Aphis gossypii</i> Glover (Hemiptera: Aphididae), is a highly polyphagous sap sucking pest on wide varieties of crops including cotton and vegetables. It is a notorious vector of many plant viruses that are persistently and non-persistently transmitted. In nature, aphids are regulated by their natural enemies. However, chemical control remains a major management tool even though resistance to insecticides has been documented worldwide. A better understanding of mechanisms by which insecticide resistance occurs and its early detection is desirable to develop effective management strategies. The present investigation was conducted to study the development of resistance to an organophosphate (OP) compound-dimethoate, identify biochemical mechanism(s) involved in resistance and study cross-resistance to imidacloprid in laboratory selected <i>A. gossypii</i> strains in comparison to susceptible strains. Bioassay studies revealed that the LC50 values increased dramatically with dimethoate selection in resistant strains and the resistance ratio (RR) was 270-, 243- and 210-fold greater than that of the susceptible strains by 30th generation. Further, biochemical assays revealed enhanced activities of carboxylesterases (CarE), glutathione S-transferases (GSTs) and cytochrome P450-mediated <i>p</i>-Nitroanisole <i>O</i>-demethylase (PNOD) in resistant strains supporting their role in dimethoate detoxification. This study thus revealed that enhanced activity of detoxifying enzymes <i>viz</i>., CarE, GSTs and PNODs is one of the mechanisms underlying dimethoate resistance in <i>A. gossypii</i> collected from South India. Interestingly, the possibility of negatively correlated cross-resistance to imidacloprid was identified in three OP- resistant strains exhibiting 2.97-, 2.56- and 3.76-fold sensitivity to imidacloprid (a novel neonicotinoid). This indicated that the latter was less affected by the resistance mechanism(s) present.
文摘为筛选出对棉蚜高效的药剂品种,选用了6种杀虫剂对棉花苗期棉蚜进行田间药效评价。试验结果表明:20%氟啶虫酰胺悬浮剂和50 g/L双丙环虫酯可分散液剂对棉蚜的速效性和持效性均较好,药后1 d仿效即可达到>88%,药后14 d防效仍能保持在>95%;20%吡虫啉可分散液剂速效性好,但持效性较差,持效期仅有7 d;20%环丙氟虫胺悬浮剂速效性和持效性均表现一般;50%吡蚜酮水分散粒剂对棉蚜防效最差。20%氟啶虫酰胺悬浮剂75 g a.i./hm^(2)、50 g/L双丙环虫酯可分散液剂7.5 g a.i./hm^(2)或12 g a.i./hm^(2)均可有效防治苗期棉蚜。
