共查询到20条相似文献，搜索用时 31 毫秒
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Rongjian Ye Haiqun Huang Zhou Yang Taiyu Chen Li Liu Xianghua Li Hao Chen Yongjun Lin 《Pest management science》2009,65(9):1015-1020
BACKGROUND: Yellow stem borer (Tryporyza incertulas Walker), striped stem borer (Chilo suppressalis Walker) and leaf folder (Cnaphalocrocis medinalis Guenec) are three lepidopteran pests that cause severe damage to rice in many areas of the world. In this study, novel insect‐resistant transgenic rice was developed in which Bt protein expression was nearly absent in the endosperm. The resistant gene, cry1C*, driven by the rice rbcS promoter (small subunit of ribulose‐1,5‐bisphosphate carboxylase/oxygenase), was introduced into Zhonghua 11 (Oryza sativa L. ssp. japonica) by Agrobacterium‐mediated transformation. RESULTS: A total of 83 independent transformants were obtained, 19 of which were characterised as single‐copy foreign gene insertion. After preliminary screening of the T1 families of these 19 transformants in the field, six highly insect‐resistant homozygous lines were selected. These six homozygous transgenic lines were field tested for resistance to leaf folders and stem borers, and for their agronomic performance. The Cry1C* protein levels in leaves and endosperm were measured by ELISA. Subsequently, the elite transgenic line RJ5 was selected; this line not only possessed high resistance to leaf folders and stem borers, normal agronomic performance, but also Cry1C* expression was only 2.6 ng g?1 in the endosperm. CONCLUSION: These results indicated that RJ5 has the potential for widespread utility in rice production. Copyright © 2009 Society of Chemical Industry 相似文献
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Characterization of field‐evolved resistance to Bacillus thuringiensis‐derived Cry1F δ‐endotoxin in Spodoptera frugiperda populations from Argentina 
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下载免费PDF全文 Desmi I Chandrasena Ana M Signorini Gustavo Abratti Nicholas P Storer Magdalena L Olaciregui Analiza P Alves Clinton D Pilcher 《Pest management science》2018,74(3):746-754
BACKGROUND
Transgenic maize (Zea mays L.) event TC1507 (Herculex® I insect protection), expressing Cry1F δ‐endotoxin derived from Bacillus thuringiensis var. aizawai, was commercialized in 2003 in the Americas. Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) susceptibility to Cry1F was monitored annually across several regions in Argentina using diagnostic concentration bioassays. Reduced performance of TC1507 maize against S. frugiperda was reported in 2013. A resistant population was established in the laboratory and the dominance of Cry1F resistance was characterized.RESULTS
During 2012–2015, high‐survivorship of several populations was observed in the resistance monitoring program. Reciprocal crosses of a Cry1F‐resistant population with a Cry1F‐susceptible population were evaluated to calculate effective dominance (DML) based on mortality levels observed at 100 µg/ml Cry1F. Two additional dominance levels (DLC and DEC) were calculated using lethal (LC50) or effective concentration (EC50) derived from concentration–response bioassays. Estimates indicated that Cry1F resistance in S. frugiperda in Argentina was either highly recessive (DML = 0.005) or incompletely recessive (DLC < 0.26 and DEC < 0.19).CONCLUSION
This study is the first documented confirmation and characterization of S. frugiperda Cry1F field‐evolved resistance in Argentina. The resistance to Cry1F in S. frugiperda populations collected in Argentina, is autosomal and incompletely recessive similar to the resistance reported in Brazil. © 2017 The Authors. Pest Management Science published by John Wiley © Sons Ltd on behalf of Society of Chemical Industry. 相似文献6.
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Segregation of non‐target‐site resistance to herbicides in multiple‐resistant Alopecurus myosuroides plants 下载免费PDF全文
下载免费PDF全文 Non‐target‐site resistance (NTSR) comprises a set of mechanisms conferring resistance to multiple modes of action. Investigation of the number of loci involved in NTSR will aid in the understanding of these resistance mechanisms. Therefore, six different multiple herbicide‐resistant Alopecurus myosuroides plants with different herbicide history were crossed in two generations with a susceptible wild type. Seeds from the backcrossing generation were studied for their segregation rate for resistance to five herbicides with four different modes of action (HRAC groups C2, A, B and K3). Taking into account that NTSR is a set of quantitative traits, the numbers of loci controlling NTSR were estimated using a normal mixture model fitted by the NLMIXED procedure of SAS. Each herbicide was controlled by a different number of loci comparing the six plants. In most of the cases, chlorotoluron resistance was controlled by one locus, whereas resistance to fenoxaprop‐P‐ethyl needed one or two loci. Resistance to pinoxaden was in all plants conferred by two loci. Cross‐resistance of fenoxaprop‐P‐ethyl and pinoxaden was found in all backcrossings, indicating that at least one of the two loci is responsible for both resistances. Resistance to mesosulfuron + iodosulfuron was conferred by a minimum of two loci. Results indicated that a minimum of five different loci can be involved in a multiple NTSR plant. Furthermore, the plant‐specific accumulation of NTSR loci was demonstrated. Such behaviour should be taken into account when evaluating the development and further spread of herbicide resistance. 相似文献
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Effects of seasonal changes in cotton plants on the evolution of resistance to pyramided cotton producing the Bt toxins Cry1Ac and Cry1F in Helicoverpa zea 下载免费PDF全文
下载免费PDF全文 Yves Carrière Ben A Degain Gopalan C Unnithan Virginia S Harpold Shannon Heuberger Xianchun Li Bruce E Tabashnik 《Pest management science》2018,74(3):627-637
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Cry1Ba3、Cry1Ia8蛋白对Cry1Ac抗性小菜蛾的杀虫活性研究 总被引：4，自引：2，他引：2
利用2种苏云金芽胞杆菌原毒素Cry1Ba3、Cry1Ia8及其组合,分别对Cry1Ac抗性种群小菜蛾幼虫进行生物活性测定。结果表明Cry1Ba3、Cry1Ia8对2种目标试虫均有高毒力,LC50分别为0.2175、0.6706μg/mL;Cry1Ba3毒力3倍于Cry1Ia8。2种蛋白混配的结果也表现出高毒力,LC50为0.4375μg/mL,没有显著的协同增效作用,也不存在拮抗。敏感与抗性小菜蛾种群生测结果统计分析比较,结果表明这2种蛋白及其组合与Cry1Ac并无交互抗性。 相似文献
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BACKGROUND: Extensive adoption of transgenic Bt corn in recent years for stalk borer control has increased risk of resistance evolution in the target pest populations. A Bt‐resistant strain of the sugarcane borer, Diatraea saccharalis, was approximately 100‐fold more tolerant to Cry1Ab toxin than the susceptible counterpart. To gain a better understanding of the molecular mechanisms of Bt resistance, the Cry1Ab‐susceptible (Cry1Ab‐SS) and Cry1Ab‐resistant (Cry1Ab‐RR) strains of D. saccharalis were subjected to a microarray analysis. RESULTS: Results showed that the expression levels of many genes were significantly different between the Cry1Ab‐RR and Cry1Ab‐SS strains. Microarray analysis of 7145 cDNAs revealed 384 differentially expressed genes. A total of 273 genes were significantly upregulated 2–51.6‐fold, and 111 genes were significantly downregulated 2–22.6‐fold in the Cry1Ab‐RR strain. The upregulation of three potential resistance‐related genes, coding for a glutathione S‐transferase (GST), a chymotrypsin‐like protease (CHY) and a lipase (LP), was confirmed using real‐time PCR, indicating a reproducibility of the microarray data. Ontology analysis revealed that more than twice the number of metabolic‐related genes were upregulated compared with downregulated genes with the same biological function. Up to 35.2% of the upregulated genes in the resistant strain were associated with catalytic activity, while only 9.5% of the downregulated genes were related to the same catalytic molecular function. CONCLUSION: The large portion of metabolic‐ or catalytic‐related genes with significant upregulations indicated a potential large increase in metabolic or catalytic activities in the Cry1Ab‐RR strain. This cDNA microarray gene expression data could be used to characterize and identify new genes that may be associated with Bt resistance in D. saccharalis. Copyright © 2012 Society of Chemical Industry 相似文献
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