The influence of four kinds of Schiff bases on a strain of Escherichia coli was studied by microcalorimetry.Differences in their capabilities of suppressing the metabolism of this bacterium were observed.The results s...The influence of four kinds of Schiff bases on a strain of Escherichia coli was studied by microcalorimetry.Differences in their capabilities of suppressing the metabolism of this bacterium were observed.The results show that the extent and duration of the inhibitory effect on the metabolism as judged from the multiplication rate constant,k,varies with different Schiff bases.The multiplication rate constant k,of Escherichia coli(in log phase)in the presence of Mo salicylioaldehyde thiadizole,Mo piperonaldehyde thiosemicarbazone and Mo 3 methoxy salicylicaldehyde thiadizole decreases with the increase of concentrations of compounds c,and the relationships between k and c,maximum heat production rate p m and c,peak time of growth curves t p and c are of linearity.For Mo 6 nitro pieronalde thiosemicarbazone,the multiplication rate constant is constant irrespective of variation in concentration.The sequence of antibiotic activity of Schiff base is:Mo salicylioaldehyde thiadizole>Mo 3 methoxy salicylicaldehyde thiadizole>Mo piperonaldehyde thiosemicarbazone>6 nitro pieronalde thiosemicarbazone.展开更多
Background The emergence of pink bollworm(PBW),Pectinophora gossypiella(Saunders)(Lepidoptera:Gelechiidae),in cotton due to Bt resistance and concealed feeding habit has created a need for alternative,eco-friendly,and...Background The emergence of pink bollworm(PBW),Pectinophora gossypiella(Saunders)(Lepidoptera:Gelechiidae),in cotton due to Bt resistance and concealed feeding habit has created a need for alternative,eco-friendly,and cost-effective control methods.This study aimed to evaluate the bio-efficacy and reproductive potential of two native strains of entomopathogenic nematodes(EPNs),Heterorhabditis indica,namely CICR-HI-CL and CICR-HI-MN,against PBW larvae and pupae under in-vitro conditions.Results The larval assay revealed that strain CICR-HI-CL exhibited higher potency than strain CICR-HI-MN against 2nd,3rd,and 4thinstar larvae,with median lethal dose(LD50)values of 5.45,4.45,and 4.60 infective juveniles(IJs)per larva,respectively.In case of pupal bioassay,both EPN strains demonstrated greater virulence when applied directly(LD50values:29.65 and 73.88 IJs per pupa for strains CICR-HI-CL and CICR-HI-MN,respectively)compared to soil application(147.84 and 272.38 IJs per pupa).Both EPN strains successfully penetrated and reproduced on 4thinstar larvae,resulting in maximum production of 19.28 and 20.85 lakh IJs per larva in the next generation when inoculated at 30 IJs per larva.Conclusion The present study has generated useful information on the virulence and reproductive potential of two strains of EPN H.indica(CICR-HI-CL and CICR-HI-MN)against PBW,a dreaded pest of cotton.Higher virulence and reproductive potential of EPN strains demonstrated their ability to multiply,sustain and perpetuate on larval and pupal stages of PBW.The knowledge generated will help formulate effective management strategies for PBW with the inclusion of EPN as a potential biological control candidate.The soil-dwelling life stages viz.,last instar hibernating larvae and pupae of PBW can be the ideal weak links to make a successful use of H.indica for sustainable management of PBW in the cotton ecosystem.However,before taking these EPN strains to field for managing PBW,detailed studies investigating their biocontrol potential against PBW under field conditions are needed.展开更多
基金The Hubei Industrial Research Project(No.630-230896)
文摘The influence of four kinds of Schiff bases on a strain of Escherichia coli was studied by microcalorimetry.Differences in their capabilities of suppressing the metabolism of this bacterium were observed.The results show that the extent and duration of the inhibitory effect on the metabolism as judged from the multiplication rate constant,k,varies with different Schiff bases.The multiplication rate constant k,of Escherichia coli(in log phase)in the presence of Mo salicylioaldehyde thiadizole,Mo piperonaldehyde thiosemicarbazone and Mo 3 methoxy salicylicaldehyde thiadizole decreases with the increase of concentrations of compounds c,and the relationships between k and c,maximum heat production rate p m and c,peak time of growth curves t p and c are of linearity.For Mo 6 nitro pieronalde thiosemicarbazone,the multiplication rate constant is constant irrespective of variation in concentration.The sequence of antibiotic activity of Schiff base is:Mo salicylioaldehyde thiadizole>Mo 3 methoxy salicylicaldehyde thiadizole>Mo piperonaldehyde thiosemicarbazone>6 nitro pieronalde thiosemicarbazone.
基金the Indian Council of Agricultural Research,New Delhi for the grant in aid through ICAR-Central Institute for Cotton Research,Nagpur Institutional Project。
文摘Background The emergence of pink bollworm(PBW),Pectinophora gossypiella(Saunders)(Lepidoptera:Gelechiidae),in cotton due to Bt resistance and concealed feeding habit has created a need for alternative,eco-friendly,and cost-effective control methods.This study aimed to evaluate the bio-efficacy and reproductive potential of two native strains of entomopathogenic nematodes(EPNs),Heterorhabditis indica,namely CICR-HI-CL and CICR-HI-MN,against PBW larvae and pupae under in-vitro conditions.Results The larval assay revealed that strain CICR-HI-CL exhibited higher potency than strain CICR-HI-MN against 2nd,3rd,and 4thinstar larvae,with median lethal dose(LD50)values of 5.45,4.45,and 4.60 infective juveniles(IJs)per larva,respectively.In case of pupal bioassay,both EPN strains demonstrated greater virulence when applied directly(LD50values:29.65 and 73.88 IJs per pupa for strains CICR-HI-CL and CICR-HI-MN,respectively)compared to soil application(147.84 and 272.38 IJs per pupa).Both EPN strains successfully penetrated and reproduced on 4thinstar larvae,resulting in maximum production of 19.28 and 20.85 lakh IJs per larva in the next generation when inoculated at 30 IJs per larva.Conclusion The present study has generated useful information on the virulence and reproductive potential of two strains of EPN H.indica(CICR-HI-CL and CICR-HI-MN)against PBW,a dreaded pest of cotton.Higher virulence and reproductive potential of EPN strains demonstrated their ability to multiply,sustain and perpetuate on larval and pupal stages of PBW.The knowledge generated will help formulate effective management strategies for PBW with the inclusion of EPN as a potential biological control candidate.The soil-dwelling life stages viz.,last instar hibernating larvae and pupae of PBW can be the ideal weak links to make a successful use of H.indica for sustainable management of PBW in the cotton ecosystem.However,before taking these EPN strains to field for managing PBW,detailed studies investigating their biocontrol potential against PBW under field conditions are needed.
