Objective:To evaluate the potential efficacy of seed extracts of Annona squamosa and Annona muricata used as natural insecticides to control adult and larvae of the vectors Aedes albopictus and Culex quinquefasciatus ...Objective:To evaluate the potential efficacy of seed extracts of Annona squamosa and Annona muricata used as natural insecticides to control adult and larvae of the vectors Aedes albopictus and Culex quinquefasciatus under laboratory conditions.Methods:Aqueous and oil extracts of the two plants were prepared from dried seeds.Preliminary identifications of the chemical components of each seed extracts were performed using microreactional and GCP techniques.Larvae and adults of Aedes albopictus and Culex quinquefasciatus were collected from the breeding sites in coastal and highlands regions of Madagascar.WHO standardized tests of susceptibility for larvae and imaginal stage of mosquitoes were realized to determine mortality and LC_(50) of mosquitoes.Results:Chemical identifications showed that these extracts contain alkaloids and flavonoids compounds that probably confer their biological insecticidal proprieties.CPG analysis showed also the presence of various fatty acids.On adult mosquitoes,significant insecticidal effects were observed with both aqueous and oil extracts of the two plant seeds compared to mortality induced by deltamethrin,an insecticide used as reference.Extracts of Annona muricata induced high mortality rate to both species of mosquito compared to extracts of Annona squamosa at all concentrations tested.The LC_(50) of seed extracts ranged from 1%to 5%for adults and 0.5%to 1%for larvae.Conclusions:The seed extracts of these two plants may be used as mosquito controlling agents and offer a new approach to a less costly,practical and environmentally friendly control of vector borne diseases.展开更多
The upstream regulatory region of a seed specific gene was isolated from the genomic DNA of Brassica napus by PCR amplification. The cloned fragment contained 1755 nucleotides, and shared a sequence homology of 99.6%...The upstream regulatory region of a seed specific gene was isolated from the genomic DNA of Brassica napus by PCR amplification. The cloned fragment contained 1755 nucleotides, and shared a sequence homology of 99.6% with the reported data. The coding region of oleic acid desaturase gene was then cloned from Arabidopsis thaliana. The sequencing analysis indicated that the sequence of the PCR product was just the same as reported before. In addition, the plant expression vector harboring the seed specific promoter and trans Fad2 gene was constructed.展开更多
基金Supported by the grants FRB-CD-AOOI-07-012 and CMIRA Coopera 2011 from Region Rhne-Alpes 11MIF-MAVINGUI-10851
文摘Objective:To evaluate the potential efficacy of seed extracts of Annona squamosa and Annona muricata used as natural insecticides to control adult and larvae of the vectors Aedes albopictus and Culex quinquefasciatus under laboratory conditions.Methods:Aqueous and oil extracts of the two plants were prepared from dried seeds.Preliminary identifications of the chemical components of each seed extracts were performed using microreactional and GCP techniques.Larvae and adults of Aedes albopictus and Culex quinquefasciatus were collected from the breeding sites in coastal and highlands regions of Madagascar.WHO standardized tests of susceptibility for larvae and imaginal stage of mosquitoes were realized to determine mortality and LC_(50) of mosquitoes.Results:Chemical identifications showed that these extracts contain alkaloids and flavonoids compounds that probably confer their biological insecticidal proprieties.CPG analysis showed also the presence of various fatty acids.On adult mosquitoes,significant insecticidal effects were observed with both aqueous and oil extracts of the two plant seeds compared to mortality induced by deltamethrin,an insecticide used as reference.Extracts of Annona muricata induced high mortality rate to both species of mosquito compared to extracts of Annona squamosa at all concentrations tested.The LC_(50) of seed extracts ranged from 1%to 5%for adults and 0.5%to 1%for larvae.Conclusions:The seed extracts of these two plants may be used as mosquito controlling agents and offer a new approach to a less costly,practical and environmentally friendly control of vector borne diseases.
文摘The upstream regulatory region of a seed specific gene was isolated from the genomic DNA of Brassica napus by PCR amplification. The cloned fragment contained 1755 nucleotides, and shared a sequence homology of 99.6% with the reported data. The coding region of oleic acid desaturase gene was then cloned from Arabidopsis thaliana. The sequencing analysis indicated that the sequence of the PCR product was just the same as reported before. In addition, the plant expression vector harboring the seed specific promoter and trans Fad2 gene was constructed.