Cylasformicarius is one of the most important pests of sweet potato worldwide, causing considerable ecological and economic damage.This study improved the effect of comprehensive management and understanding of geneti...Cylasformicarius is one of the most important pests of sweet potato worldwide, causing considerable ecological and economic damage.This study improved the effect of comprehensive management and understanding of genetic mechanisms by examining the functional genomics of C. formicarius.Using Illumina and PacBio sequencing, this study obtained a chromosome-level genome assembly of adult weevils from lines inbred for 15 generations.The high-quality assembly obtained was 338.84 Mb, with contig and scaffold N50 values of 14.97 and 34.23 Mb, respectively.In total, 157.51 Mb of repeat sequences and 11 907 protein-coding genes were predicted.A total of 337.06 Mb of genomic sequences was located on the 11 chromosomes, accounting for 99.03%of the total length of the associated chromosome.Comparative genomic analysis showed that C. formicarius was sister to Dendroctonus ponderosae, and C. formicarius diverged from D. ponderosae approximately 138.89 million years ago (Mya).Many important gene families expanded in the C. formicarius genome were involved in the detoxification of pesticides, tolerance to cold stress and chemosensory system.To further study the role of odorant-binding proteins (OBPs) in olfactory recognition of C. formicarius, the binding assay results indicated that Cfor OBP4–6 had strong binding affinities for sex pheromones and other ligands.The high-quality C. formicarius genome provides a valuable resource to reveal the molecular ecological basis, genetic mechanism, and evolutionary process of major agricultural pests;it also offers new ideas and new technologies for ecologically sustainable pest control.展开更多
[Objectives] This study was conducted to expand the insect resistance spectrum of tea saponin, and its control effect on Cylas formicarius and the potential as an insecticide for pest control were explored. [Methods] ...[Objectives] This study was conducted to expand the insect resistance spectrum of tea saponin, and its control effect on Cylas formicarius and the potential as an insecticide for pest control were explored. [Methods] The olfactory avoidance rate of C. formicarius to tea saponin aqueous solution was determined by Y-type olfactometer;the feeding avoidance rate of C. formicarius to tea saponin was determined by the selective method;the antifeedant rate of C. formicarius to tea saponin was determined by non-selective method;and the development duration and mortality of C. formicarius under the influence of tea saponin were determined by artificial feeding method. [Results] C. formicarius had no significant olfactory tendency to every concentration of tea saponin, and the olfactory avoidance rate of 20.0% tea saponin aqueous solution was only 9.14%. Tea saponin had a feeding avoidance effect on C. formicarius, and the avoidance rate increased with the increase of tea saponin concentration. At 6 h, the feeding avoidance rates of 0.5%, 1.0%, 5.0%, 10.0% and 20.0% tea saponin on C. formicarius were 58.14%, 77.77%, 88.23%, 95.00% and 97.65 %, respectively;and the feeding avoidance effect at 6 h was significant, and the feeding avoidance rate was higher than that of 1 h. Tea saponin had a significant antifeedant effect on C. formicarius, and the longer the feeding time, the higher the antifeedant rate. At 72 h, the antifeedant rates of 0.5%, 1.0%, 5.0%, 10.0 % and 20.0% tea saponin to C. formicarius were 63.01%, 67.54%, 97.14 %, 96.42% and 98.57%, respectively. The larval development duration of C. formicarius was shortened with the increase of tea saponin concentration, and the larval death occurred. The development duration of larvae under the influence of 1.0% tea saponin was the shortest, which was 4.01 d shorter than that of the control, and the mortality was the highest, which was 26.65%. [Conclusions] Tea saponin had neither olfactory avoidance effect nor olfactory attracting effect to C. formicarius, but had obvious feeding avoidance effect and strong antifeedant effect. Tea saponin can shorten the development duration of the larvae of C. formicarius and cause the death of the larvae.展开更多
Sweet potato [Ipomoea batatas （L.） Lam.] is an important food crop in the world as well as in Vietnam. It is well known as a recalcitrant crop for gene transformation and tissue culture because of its genotype depen...Sweet potato [Ipomoea batatas （L.） Lam.] is an important food crop in the world as well as in Vietnam. It is well known as a recalcitrant crop for gene transformation and tissue culture because of its genotype dependent in vitro responses. In present study, Agrobacterium-mediated transformation of cry8Db from Bacillus thuringiensis into KB 1 sweet potato variety has been studied. The C58cv strain carrying a pBl 121 backbone which contained cry8Db delta-endotoxin gene regulated under 35 S CaMV prom oter, and the selection marker gene, neomycin phosphotransferase （npt11） gene, was subjected for plant transformation. Callus induced from shoot tips and leaf explants were inoculated and cocultured with A. tumefaciens. The selection occurred during callus producing and plant regenerating steps. A total of 201 transgenic putative plant lines were produced, and 21 transgenic lines were positively confirmed by PCR and finalized by Southern blot. Four putative transgenic lines confirming a single copy of the crySEIb gene were transferred into soil pots in greenhouse. Biological activity evaluation for the insecticidal capacity of these transgenic lines under controlled conditions showed that the level of infestation by sweet potato weevils （Cylasformicarius） in untransformed plants was higher than that of transgenic lines.展开更多
基金supported by the Natural Science Foundation of Guangxi Autonomous Region,China(2022GXNSFAA035558)the Technology Development Foundation of Guangxi Academy of Agricultural Sciences(2021ZX09)+2 种基金the China Agriculture Research System of MOF and MARA(CARS-10-B3 and CARS-10-C19)the Guangxi Innovation Team Construction Project(nycytxgxcxtd-11-03)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),China。
文摘Cylasformicarius is one of the most important pests of sweet potato worldwide, causing considerable ecological and economic damage.This study improved the effect of comprehensive management and understanding of genetic mechanisms by examining the functional genomics of C. formicarius.Using Illumina and PacBio sequencing, this study obtained a chromosome-level genome assembly of adult weevils from lines inbred for 15 generations.The high-quality assembly obtained was 338.84 Mb, with contig and scaffold N50 values of 14.97 and 34.23 Mb, respectively.In total, 157.51 Mb of repeat sequences and 11 907 protein-coding genes were predicted.A total of 337.06 Mb of genomic sequences was located on the 11 chromosomes, accounting for 99.03%of the total length of the associated chromosome.Comparative genomic analysis showed that C. formicarius was sister to Dendroctonus ponderosae, and C. formicarius diverged from D. ponderosae approximately 138.89 million years ago (Mya).Many important gene families expanded in the C. formicarius genome were involved in the detoxification of pesticides, tolerance to cold stress and chemosensory system.To further study the role of odorant-binding proteins (OBPs) in olfactory recognition of C. formicarius, the binding assay results indicated that Cfor OBP4–6 had strong binding affinities for sex pheromones and other ligands.The high-quality C. formicarius genome provides a valuable resource to reveal the molecular ecological basis, genetic mechanism, and evolutionary process of major agricultural pests;it also offers new ideas and new technologies for ecologically sustainable pest control.
基金Supported by National Modern Agricultural Industry Technology System Guangxi Industry Potato Innovation Team(nycytxgxcxtd-11-01)Guangxi Science and Technology Planning Project(GK AB16380046,GK AB18221101)
文摘[Objectives] This study was conducted to expand the insect resistance spectrum of tea saponin, and its control effect on Cylas formicarius and the potential as an insecticide for pest control were explored. [Methods] The olfactory avoidance rate of C. formicarius to tea saponin aqueous solution was determined by Y-type olfactometer;the feeding avoidance rate of C. formicarius to tea saponin was determined by the selective method;the antifeedant rate of C. formicarius to tea saponin was determined by non-selective method;and the development duration and mortality of C. formicarius under the influence of tea saponin were determined by artificial feeding method. [Results] C. formicarius had no significant olfactory tendency to every concentration of tea saponin, and the olfactory avoidance rate of 20.0% tea saponin aqueous solution was only 9.14%. Tea saponin had a feeding avoidance effect on C. formicarius, and the avoidance rate increased with the increase of tea saponin concentration. At 6 h, the feeding avoidance rates of 0.5%, 1.0%, 5.0%, 10.0% and 20.0% tea saponin on C. formicarius were 58.14%, 77.77%, 88.23%, 95.00% and 97.65 %, respectively;and the feeding avoidance effect at 6 h was significant, and the feeding avoidance rate was higher than that of 1 h. Tea saponin had a significant antifeedant effect on C. formicarius, and the longer the feeding time, the higher the antifeedant rate. At 72 h, the antifeedant rates of 0.5%, 1.0%, 5.0%, 10.0 % and 20.0% tea saponin to C. formicarius were 63.01%, 67.54%, 97.14 %, 96.42% and 98.57%, respectively. The larval development duration of C. formicarius was shortened with the increase of tea saponin concentration, and the larval death occurred. The development duration of larvae under the influence of 1.0% tea saponin was the shortest, which was 4.01 d shorter than that of the control, and the mortality was the highest, which was 26.65%. [Conclusions] Tea saponin had neither olfactory avoidance effect nor olfactory attracting effect to C. formicarius, but had obvious feeding avoidance effect and strong antifeedant effect. Tea saponin can shorten the development duration of the larvae of C. formicarius and cause the death of the larvae.
文摘Sweet potato [Ipomoea batatas （L.） Lam.] is an important food crop in the world as well as in Vietnam. It is well known as a recalcitrant crop for gene transformation and tissue culture because of its genotype dependent in vitro responses. In present study, Agrobacterium-mediated transformation of cry8Db from Bacillus thuringiensis into KB 1 sweet potato variety has been studied. The C58cv strain carrying a pBl 121 backbone which contained cry8Db delta-endotoxin gene regulated under 35 S CaMV prom oter, and the selection marker gene, neomycin phosphotransferase （npt11） gene, was subjected for plant transformation. Callus induced from shoot tips and leaf explants were inoculated and cocultured with A. tumefaciens. The selection occurred during callus producing and plant regenerating steps. A total of 201 transgenic putative plant lines were produced, and 21 transgenic lines were positively confirmed by PCR and finalized by Southern blot. Four putative transgenic lines confirming a single copy of the crySEIb gene were transferred into soil pots in greenhouse. Biological activity evaluation for the insecticidal capacity of these transgenic lines under controlled conditions showed that the level of infestation by sweet potato weevils （Cylasformicarius） in untransformed plants was higher than that of transgenic lines.
