[Objective] To study the long-term ultra-dry storage method and genetic stability of vegetable seeds.[Method] Seeds of Lycopersicum esculentum,Raphanus satuvus and Apium graveolen.were chosen as material.The changes o...[Objective] To study the long-term ultra-dry storage method and genetic stability of vegetable seeds.[Method] Seeds of Lycopersicum esculentum,Raphanus satuvus and Apium graveolen.were chosen as material.The changes of seed vigor,viability and genetic stability after ultra-storage were discussed by studying the seed potentiality,shoot length,germination percentage and the chromosome aberration rate of root tip cells.[Results] Maintaining the low moisture content,different vegetable species had different storage effects of the long-term storage seeds under normal temperature.The Lycopersicum esculentum and Raphanus satuvus seeds were more suitable to ultra-dry storage at normal temperature,and could keep good genetic stability,while the seeds of Apium graveolen had bad performance.[Conclusion] This study established the foundation of studying ultra-dry storage of vegetable seeds.展开更多
[Objectives] This study was conducted to better understand the variation law of sugarcane clones during tissue culture process,and to provide a reference for rapid propagation and detection of healthy sugarcane seedli...[Objectives] This study was conducted to better understand the variation law of sugarcane clones during tissue culture process,and to provide a reference for rapid propagation and detection of healthy sugarcane seedlings.[Methods] The genetic stability of tissue culture clones of three sugarcane varieties was analyzed using the AFLP molecular marker technique.[Results]The average number of polymorphic loci was 19. 58 for each primer pair,and the percentage of polymorphic loci was 41. 74%. Compared with the donor varieties,all tissue culture materials were mutated. There were 3-16 missing bands,with an average of 5. 2 bands,and there were 0-17 increased bands,with an average of 3. 3 bands. The total number of missing and increased bands was 4-33,with an average of 8. 5. The band difference rates were in the range of 0. 009 4%-0. 077 6%,with an average of 0. 020 6%. The genetic similarity coefficients between materials ranged from 0. 685 6 to 0. 998 2,with an average of 0. 818 4. The three sugarcane varieties and their tissue culture clones were clustered into three groups.[Conclusions] Although variations occur in tissue culture,the variations are not too obvious,and the genetic stability is relatively high. It is recommended to minimize the number of subculture generations and cultivation time to reduce the occurrence of variation during tissue culture for rapid propagation of sugarcane seedlings.展开更多
To regenerate adventitious shoots from the cotyledon proximal parts of Citrullus lanatus (Thunb.) Matsum. and Nakai ssp. mucosospermus (Fursa) oleaginous type, different concentrations of MS mineral elements, sucrose,...To regenerate adventitious shoots from the cotyledon proximal parts of Citrullus lanatus (Thunb.) Matsum. and Nakai ssp. mucosospermus (Fursa) oleaginous type, different concentrations of MS mineral elements, sucrose, 6-benzylaminopurine (BAP) and agar were tested. Shoot induction proved to depend on the interaction between levels of sucrose, BAP and MS mineral elements in the medium. The medium containing 3/2 strength of MS mineral elements, 35 g/l sucrose and 1 mg/l BAP solidified with 6 g/l agar allowed the production of numerous shoots without a callus phase. After 3 weeks of culture, 76.7% of the cotyledon proximal parts induced shoots with an average of 12.26 shoots per explant and a mean shoot length of 17.13 mm. The induced shoots were directly rooted and thus complete plants ready for acclimatization were obtained using a two steps procedure. Depending on the genotype, the shoot induction from cotyledon proximal parts ranged from 54% to 96%. Rooted plantlets were acclimatized and transferred to field, where they grew well, developed flowers and fruits like seeded plants. The assessment of the genetic stability of the in-vitro-regenerated plantlets by means of an Amplified Fragment Length Polymorphism (AFLP) analysis with the combination of 5 primers revealed no differences between regenerated plantlets and mother plants.展开更多
Genetically modified wheat has not been commercially utilized in agriculture largely due to regulatory hurdles associated with traditional transformation methods. Development of marker-free transgenic wheat plants wil...Genetically modified wheat has not been commercially utilized in agriculture largely due to regulatory hurdles associated with traditional transformation methods. Development of marker-free transgenic wheat plants will help to facilitate biosafety evaluation and the eventual environmental release of transgenic wheat varieties. In this study, the marker-free transgenic wheat plants previously obtained by Agrobacterium-mediated co-transformation of double T-DNAs vector were identified by fluorescence in situ hybridization(FISH) in the T1 generation, and their genetic stability and agronomic traits were analyzed in T2 and T3 generations. FISH analysis indicated that the transgene often integrated into a position at the distal region of wheat chromosomes. Furthermore, we show that the GUS transgene was stably inherited in the marker-free transgenic plants in T1 to T3 generations. No significant differences in agronomic traits or grain characteristics were observed in T3 generation, with the exception of a small variation in spike length and grains per spike in a few lines. The selection marker of bar gene was not found in the transgenic plants through T1 to T3 generations. The results from this investigation lay a solid foundation for the potential application of the marker-free transgenic wheat plants achieved through the co-transformation of double T-DNAs vector by Agrobacterium in agriculture after biosafty evaluation.展开更多
Shandong province,located in the Lower Yellow River,is one of the birthplaces of ancient Chinese civilization.However,the comprehensive genetic histories of this region have remained largely unknown until now due to a...Shandong province,located in the Lower Yellow River,is one of the birthplaces of ancient Chinese civilization.However,the comprehensive genetic histories of this region have remained largely unknown until now due to a lack of ancient human genomes.Here,we present 21 ancient genomes from Shandong dating from the Warring States period to the Northern Dynasties.Unlike the early Neolithic samples from Shandong,the historical samples are most closely related to post-Late Neolithic populations of the Middle Yellow River Basin,suggesting a population turnover in Shandong from the Neolithic Age to the Historical era.In addition,we detect a close genetic affinity between the historical samples in Shandong and present-day Han Chinese,showing long-term genetic stability in Han Chinese,at least since the Warring States period.展开更多
Background:Spinocerebellar ataxia type 2(SCA2)is a neurodegenerative disease marked by significant clinical and genetic heterogeneity,primarily caused by expanded CAG mutations in the ATXN2 gene.The unstable expansion...Background:Spinocerebellar ataxia type 2(SCA2)is a neurodegenerative disease marked by significant clinical and genetic heterogeneity,primarily caused by expanded CAG mutations in the ATXN2 gene.The unstable expansion of CAG repeats disrupts the genetic stability of animal models,which is detrimental to disease research.Methods:In this study,we established a mouse model in which CAG repeats do not undergo microsatellite instability(MSI)across generations.A humanized ATXN2 cDNA with four CAA interruptions within 73 CAG expansions was inserted into the Rosa26 locus of C57BL/6J mice.A 23 CAG control mouse model was also generated to verify ATXN2 integration and expression.Results:In our model,the number of CAG repeats remained stable during transmission,with no CAG repeat expansion observed in 64 parent-to-offspring transmissions.Compared with SCA2-Q23 mice,SCA2-Q73 mice exhibited progressive motor impairment,reduced Purkinje cell count and volume(indicative of cell atrophy),and muscle atrophy.These observations in the mice suggest that the behavioral and neuropathological phenotypes may reflect the features of SCA2 patients.RNA-seq analysis of the gastrocnemius muscle in SCA2-Q73 mice showed significant changes in muscle differentiation and development gene expression at 56 weeks,with no significant differences at 16 weeks compared to SCA2-Q23 mice.The expression level of the Myf6 gene significantly changed in the muscles of aged mice.Conclusion:In summary,the establishment of this model not only provides a stable animal model for studying CAG transmission in SCA2 but also indicates that the lack of long-term neural stimulation leads to muscle atrophy.展开更多
To detect retrospectively the phenotype and stability of the E-protein gene in Japanese Encephalitis （JE） virus strain SA14-14-2 used in the live-attenuated JE vaccine prepears, the viral titer was titrated by plaqu...To detect retrospectively the phenotype and stability of the E-protein gene in Japanese Encephalitis （JE） virus strain SA14-14-2 used in the live-attenuated JE vaccine prepears, the viral titer was titrated by plaque formation in BHK-21 cell cultures, and the neuro-virulence of viruses was assayed in mice with body weight of 12-14 g by intracerebral inoculation. Meanwhile, the total RNA of virus gene was extracted and amplified by RT-PCR with the designed primers, and then it was purified and cloned to the expression vector pGEM-T. The recombinant plasmid was purified and sequenced. It was found that the loss of viral titer of vaccines stored in -20℃ for longer than 10 years was less than 0.5 Lg PFU/ml. No mice inoculated intracerebrally showed signs of illness or even death. The size of plagues of the vaccine virus remained to be small, and the E genes of primary virus seed SA14-14-2 and the vaccines prepared at different years （1987-2001） were unchanged, in- cluding the 8 critical amino acid sites which were different from the parent wild virus strain SA14 and the related neuro-virulence. These results indicate that the genotypic and biological characteristics of the attenuated JE virus strain SA14-14-2 and its vaccines sion noted. prepared are quite stable without any reversion noted.展开更多
Objective In China, 24 cases of human infection with highly pathogenic avian influenza(HPAI) H5 N6 virus have been confirmed since the first confirmed case in 2014. Therefore, we developed and assessed two H5 N6 candi...Objective In China, 24 cases of human infection with highly pathogenic avian influenza(HPAI) H5 N6 virus have been confirmed since the first confirmed case in 2014. Therefore, we developed and assessed two H5 N6 candidate vaccine viruses(CVVs).Methods In accordance with the World Health Organization(WHO) recommendations, we constructed two reassortant viruses using reverse genetics(RG) technology to match the two different epidemic H5 N6 viruses. We performed complete genome sequencing to determine the genetic stability. We assessed the growth ability of the studied viruses in MDCK cells and conducted a hemagglutination inhibition assay to analyze their antigenicity. Pathogenicity attenuation was also evaluated in vitro and in vivo.Results The results showed that no mutations occurred in hemagglutinin or neuraminidase, and both CVVs retained their original antigenicity. The replication capacity of the two CVVs reached a level similar to that of A/Puerto Rico/8/34 in MDCK cells. The two CVVs showed low pathogenicity in vitro and in vivo, which are in line with the WHO requirements for CVVs.Conclusion We obtained two genetically stable CVVs of HPAI H5N6 with high growth characteristics,which may aid in our preparedness for a potential H5N6 pandemic.展开更多
Populus alba is a large woody deciduous plant.The plant has been introduced to shooting,then multiplication of rooting on Murashige and Skoog(MS)medium.This work was designed to estimate the effect of two factors(low ...Populus alba is a large woody deciduous plant.The plant has been introduced to shooting,then multiplication of rooting on Murashige and Skoog(MS)medium.This work was designed to estimate the effect of two factors(low levels of 1-Naphthaleneacetic acid NAA and sucrose)on P.alba response resulting in 6 treatments compared to the control,with twelve measured responses.There was a significant difference in some measurements in morphology,like plantlets fresh-weight,shoot-,root-length,and leaf number.In the physiological measurements,there were significant differences in all the measured parameters.The low concentrations of sucrose and media composition/power(MS grams/L)led to starvation in plants;however,these conditions led to enhancement in some morphological and physiological parameters to overcome the starvation effect,compared to the control.The RAPD-PCR molecular marker(four decamers)was used to evaluate the new individuals’genetic variation(instability),resulting in a total polymorphism percentage of 50.83%.It was formerly known that the plantlets were identical to each other and to the mother plant.In this study,however,the use of distinct media power,hormonal and sucrose levels resulted in molecular variation reflected in P.alba’s morphological and physiological responses.展开更多
Genetic and expressional stability of Bt toxin gene is crucial for the breeding of insect-resistant transgenic cotton varieties and their commercialization. Genomic Southern blot analysis of R3, R4 and R5 generations ...Genetic and expressional stability of Bt toxin gene is crucial for the breeding of insect-resistant transgenic cotton varieties and their commercialization. Genomic Southern blot analysis of R3, R4 and R5 generations of bivalent transgenic insect-resistant cotton plants was done in order to determine the integration, the copy number and the inheritance stability of Bt toxin gene in the transgenic cotton plants. The results indicated that there was a 4.7 kb positive band in the Southern blot when the genomic DNA of the bivalent transgenic insect-resistant cotton plants and the positive control (the plasmid) were digested with HindⅢ respectively. This result proved that the Bt toxin gene had been integrated into the genome of the cotton in full length. There is only one XhoⅠ restriction site in the Bt toxin gene. Southern blot analysis indicated that many copies of Bt toxin gene had been integrated into the genome of the cotton when the genomic DNA of transgenic plants was digested with XhoⅠ. Among them, there were four copies (about 17.7, 8, 5.5 and 4.7 kb in size) existing in all the tested plants of R3, R4 and R5 generations. The preliminary conclusion was that there were more than four copies of Bt toxin gene integrated into the genome of the cotton, among them, more than one copy can express and inherit steadily. This result provides a scientific basis for the breeding of the bivalent insect-resis- tant transgenic cotton plants and its commercialization.展开更多
基金Supported by Beijing Nova Program (2008B37)Beijing Municipal Scientific Research Foundation for the Returned Overseas ChineseScholars (20080006)~~
文摘[Objective] To study the long-term ultra-dry storage method and genetic stability of vegetable seeds.[Method] Seeds of Lycopersicum esculentum,Raphanus satuvus and Apium graveolen.were chosen as material.The changes of seed vigor,viability and genetic stability after ultra-storage were discussed by studying the seed potentiality,shoot length,germination percentage and the chromosome aberration rate of root tip cells.[Results] Maintaining the low moisture content,different vegetable species had different storage effects of the long-term storage seeds under normal temperature.The Lycopersicum esculentum and Raphanus satuvus seeds were more suitable to ultra-dry storage at normal temperature,and could keep good genetic stability,while the seeds of Apium graveolen had bad performance.[Conclusion] This study established the foundation of studying ultra-dry storage of vegetable seeds.
基金Supported by Action Fund for the Guangdong Academy of Sciences Special Funds for Building Top-ranking Research Institutions in China(2019GDASYL-0104013)Science and Technology Program of Guangzhou(201804010418)+1 种基金National Key R&D Program of China(2018YFD1000503)China Agriculture Research System of Sugar(CARS201707)
文摘[Objectives] This study was conducted to better understand the variation law of sugarcane clones during tissue culture process,and to provide a reference for rapid propagation and detection of healthy sugarcane seedlings.[Methods] The genetic stability of tissue culture clones of three sugarcane varieties was analyzed using the AFLP molecular marker technique.[Results]The average number of polymorphic loci was 19. 58 for each primer pair,and the percentage of polymorphic loci was 41. 74%. Compared with the donor varieties,all tissue culture materials were mutated. There were 3-16 missing bands,with an average of 5. 2 bands,and there were 0-17 increased bands,with an average of 3. 3 bands. The total number of missing and increased bands was 4-33,with an average of 8. 5. The band difference rates were in the range of 0. 009 4%-0. 077 6%,with an average of 0. 020 6%. The genetic similarity coefficients between materials ranged from 0. 685 6 to 0. 998 2,with an average of 0. 818 4. The three sugarcane varieties and their tissue culture clones were clustered into three groups.[Conclusions] Although variations occur in tissue culture,the variations are not too obvious,and the genetic stability is relatively high. It is recommended to minimize the number of subculture generations and cultivation time to reduce the occurrence of variation during tissue culture for rapid propagation of sugarcane seedlings.
文摘To regenerate adventitious shoots from the cotyledon proximal parts of Citrullus lanatus (Thunb.) Matsum. and Nakai ssp. mucosospermus (Fursa) oleaginous type, different concentrations of MS mineral elements, sucrose, 6-benzylaminopurine (BAP) and agar were tested. Shoot induction proved to depend on the interaction between levels of sucrose, BAP and MS mineral elements in the medium. The medium containing 3/2 strength of MS mineral elements, 35 g/l sucrose and 1 mg/l BAP solidified with 6 g/l agar allowed the production of numerous shoots without a callus phase. After 3 weeks of culture, 76.7% of the cotyledon proximal parts induced shoots with an average of 12.26 shoots per explant and a mean shoot length of 17.13 mm. The induced shoots were directly rooted and thus complete plants ready for acclimatization were obtained using a two steps procedure. Depending on the genotype, the shoot induction from cotyledon proximal parts ranged from 54% to 96%. Rooted plantlets were acclimatized and transferred to field, where they grew well, developed flowers and fruits like seeded plants. The assessment of the genetic stability of the in-vitro-regenerated plantlets by means of an Amplified Fragment Length Polymorphism (AFLP) analysis with the combination of 5 primers revealed no differences between regenerated plantlets and mother plants.
基金the Ministry of Agriculture of China for the National Transgenic Research Program (2016ZX08010004)the Chinese Academy of Agricultural Sciences for the Agricultural Science and Technology Innovation Program (ASTIP-2060302-2-19)
文摘Genetically modified wheat has not been commercially utilized in agriculture largely due to regulatory hurdles associated with traditional transformation methods. Development of marker-free transgenic wheat plants will help to facilitate biosafety evaluation and the eventual environmental release of transgenic wheat varieties. In this study, the marker-free transgenic wheat plants previously obtained by Agrobacterium-mediated co-transformation of double T-DNAs vector were identified by fluorescence in situ hybridization(FISH) in the T1 generation, and their genetic stability and agronomic traits were analyzed in T2 and T3 generations. FISH analysis indicated that the transgene often integrated into a position at the distal region of wheat chromosomes. Furthermore, we show that the GUS transgene was stably inherited in the marker-free transgenic plants in T1 to T3 generations. No significant differences in agronomic traits or grain characteristics were observed in T3 generation, with the exception of a small variation in spike length and grains per spike in a few lines. The selection marker of bar gene was not found in the transgenic plants through T1 to T3 generations. The results from this investigation lay a solid foundation for the potential application of the marker-free transgenic wheat plants achieved through the co-transformation of double T-DNAs vector by Agrobacterium in agriculture after biosafty evaluation.
基金funded by the Shandong Province Humanities and Social Sciences Project“Sorting and Research on Human Bones of Han Dynasty Excavated from the Medical Center Cemetery in Linzi”granted to Zhigang Wu(2022-JCLS-12)the National Key Research and Development Program(2023YFC3303701-02)+5 种基金the National Natural Science Foundation of China(32270667)the Natural Science Foundation of Fujian Province of China(2023J06013)the Major Project of the National Social Science Foundation of China granted to Chuan-Chao Wang(21&ZD285)Open Research Fund of State Key Laboratory of Genetic Engineering at Fudan University(No.SKLGE-2310)Open Research Fund of Forensic Genetics Key Laboratory of the Ministry of Public Security(2023FGKFKT07)Major Special Project of Philosophy and Social Sciences Research of the Ministry of Education(2022JZDZ023).
文摘Shandong province,located in the Lower Yellow River,is one of the birthplaces of ancient Chinese civilization.However,the comprehensive genetic histories of this region have remained largely unknown until now due to a lack of ancient human genomes.Here,we present 21 ancient genomes from Shandong dating from the Warring States period to the Northern Dynasties.Unlike the early Neolithic samples from Shandong,the historical samples are most closely related to post-Late Neolithic populations of the Middle Yellow River Basin,suggesting a population turnover in Shandong from the Neolithic Age to the Historical era.In addition,we detect a close genetic affinity between the historical samples in Shandong and present-day Han Chinese,showing long-term genetic stability in Han Chinese,at least since the Warring States period.
基金CAMS Innovation Fund for Medical Sciences,Grant/Award Number:CIFMS,2021-I2M-1-024The Joint Fund for the Department of Science and Technology of Yunnan Province-Kunming Medical University,Grant/Award Number:202201AY070001-007+1 种基金Open Research Fund Project of Yunnan Provincial Key Laboratory of Pharmacology of Natural Medicines,Grant/Award Number:YKLPNP-G2403The Science and Technology Leading Talent Program of Yunnan Province,Grant/Award Number:202405AB350002。
文摘Background:Spinocerebellar ataxia type 2(SCA2)is a neurodegenerative disease marked by significant clinical and genetic heterogeneity,primarily caused by expanded CAG mutations in the ATXN2 gene.The unstable expansion of CAG repeats disrupts the genetic stability of animal models,which is detrimental to disease research.Methods:In this study,we established a mouse model in which CAG repeats do not undergo microsatellite instability(MSI)across generations.A humanized ATXN2 cDNA with four CAA interruptions within 73 CAG expansions was inserted into the Rosa26 locus of C57BL/6J mice.A 23 CAG control mouse model was also generated to verify ATXN2 integration and expression.Results:In our model,the number of CAG repeats remained stable during transmission,with no CAG repeat expansion observed in 64 parent-to-offspring transmissions.Compared with SCA2-Q23 mice,SCA2-Q73 mice exhibited progressive motor impairment,reduced Purkinje cell count and volume(indicative of cell atrophy),and muscle atrophy.These observations in the mice suggest that the behavioral and neuropathological phenotypes may reflect the features of SCA2 patients.RNA-seq analysis of the gastrocnemius muscle in SCA2-Q73 mice showed significant changes in muscle differentiation and development gene expression at 56 weeks,with no significant differences at 16 weeks compared to SCA2-Q23 mice.The expression level of the Myf6 gene significantly changed in the muscles of aged mice.Conclusion:In summary,the establishment of this model not only provides a stable animal model for studying CAG transmission in SCA2 but also indicates that the lack of long-term neural stimulation leads to muscle atrophy.
文摘To detect retrospectively the phenotype and stability of the E-protein gene in Japanese Encephalitis （JE） virus strain SA14-14-2 used in the live-attenuated JE vaccine prepears, the viral titer was titrated by plaque formation in BHK-21 cell cultures, and the neuro-virulence of viruses was assayed in mice with body weight of 12-14 g by intracerebral inoculation. Meanwhile, the total RNA of virus gene was extracted and amplified by RT-PCR with the designed primers, and then it was purified and cloned to the expression vector pGEM-T. The recombinant plasmid was purified and sequenced. It was found that the loss of viral titer of vaccines stored in -20℃ for longer than 10 years was less than 0.5 Lg PFU/ml. No mice inoculated intracerebrally showed signs of illness or even death. The size of plagues of the vaccine virus remained to be small, and the E genes of primary virus seed SA14-14-2 and the vaccines prepared at different years （1987-2001） were unchanged, in- cluding the 8 critical amino acid sites which were different from the parent wild virus strain SA14 and the related neuro-virulence. These results indicate that the genotypic and biological characteristics of the attenuated JE virus strain SA14-14-2 and its vaccines sion noted. prepared are quite stable without any reversion noted.
基金This study was supported by the National Major Science and Technology Project for Control and Prevention of Major Infectious Diseases in China[No.2018ZX10711001,2018ZX10305409-004-002]Emergency Prevention and Control Project of Ministry of Science and Technology of China[No.10600100000015001206].
文摘Objective In China, 24 cases of human infection with highly pathogenic avian influenza(HPAI) H5 N6 virus have been confirmed since the first confirmed case in 2014. Therefore, we developed and assessed two H5 N6 candidate vaccine viruses(CVVs).Methods In accordance with the World Health Organization(WHO) recommendations, we constructed two reassortant viruses using reverse genetics(RG) technology to match the two different epidemic H5 N6 viruses. We performed complete genome sequencing to determine the genetic stability. We assessed the growth ability of the studied viruses in MDCK cells and conducted a hemagglutination inhibition assay to analyze their antigenicity. Pathogenicity attenuation was also evaluated in vitro and in vivo.Results The results showed that no mutations occurred in hemagglutinin or neuraminidase, and both CVVs retained their original antigenicity. The replication capacity of the two CVVs reached a level similar to that of A/Puerto Rico/8/34 in MDCK cells. The two CVVs showed low pathogenicity in vitro and in vivo, which are in line with the WHO requirements for CVVs.Conclusion We obtained two genetically stable CVVs of HPAI H5N6 with high growth characteristics,which may aid in our preparedness for a potential H5N6 pandemic.
文摘Populus alba is a large woody deciduous plant.The plant has been introduced to shooting,then multiplication of rooting on Murashige and Skoog(MS)medium.This work was designed to estimate the effect of two factors(low levels of 1-Naphthaleneacetic acid NAA and sucrose)on P.alba response resulting in 6 treatments compared to the control,with twelve measured responses.There was a significant difference in some measurements in morphology,like plantlets fresh-weight,shoot-,root-length,and leaf number.In the physiological measurements,there were significant differences in all the measured parameters.The low concentrations of sucrose and media composition/power(MS grams/L)led to starvation in plants;however,these conditions led to enhancement in some morphological and physiological parameters to overcome the starvation effect,compared to the control.The RAPD-PCR molecular marker(four decamers)was used to evaluate the new individuals’genetic variation(instability),resulting in a total polymorphism percentage of 50.83%.It was formerly known that the plantlets were identical to each other and to the mother plant.In this study,however,the use of distinct media power,hormonal and sucrose levels resulted in molecular variation reflected in P.alba’s morphological and physiological responses.
基金supported by the National"863"High-Tech Program,the Special Foundation of the Ministry of Agriculture for"Developing Cotton Production"and the Chinese Foundation for Agriculture Science and Education.
文摘Genetic and expressional stability of Bt toxin gene is crucial for the breeding of insect-resistant transgenic cotton varieties and their commercialization. Genomic Southern blot analysis of R3, R4 and R5 generations of bivalent transgenic insect-resistant cotton plants was done in order to determine the integration, the copy number and the inheritance stability of Bt toxin gene in the transgenic cotton plants. The results indicated that there was a 4.7 kb positive band in the Southern blot when the genomic DNA of the bivalent transgenic insect-resistant cotton plants and the positive control (the plasmid) were digested with HindⅢ respectively. This result proved that the Bt toxin gene had been integrated into the genome of the cotton in full length. There is only one XhoⅠ restriction site in the Bt toxin gene. Southern blot analysis indicated that many copies of Bt toxin gene had been integrated into the genome of the cotton when the genomic DNA of transgenic plants was digested with XhoⅠ. Among them, there were four copies (about 17.7, 8, 5.5 and 4.7 kb in size) existing in all the tested plants of R3, R4 and R5 generations. The preliminary conclusion was that there were more than four copies of Bt toxin gene integrated into the genome of the cotton, among them, more than one copy can express and inherit steadily. This result provides a scientific basis for the breeding of the bivalent insect-resis- tant transgenic cotton plants and its commercialization.
