[Objective] The aim was to study the genetic diversities between Xiaogan water chestnut and wild chestnut with randomly amplified polymorphic DNA (RAPD) technology. [Method] Genetic diversities of the local cultivat...[Objective] The aim was to study the genetic diversities between Xiaogan water chestnut and wild chestnut with randomly amplified polymorphic DNA (RAPD) technology. [Method] Genetic diversities of the local cultivated water chestnut,wild chestnut,Lepironia articulata and Scirpus planiculmis Fr. Schmidt were analyzed by RAPD technology. [Result] Among the screened random primers 841,842,807 and 840,the polymorphism of amplification product of 841 was evident,and the obtained bands in electrophoresis were clear and showed good repeatability. Cluster analysis result showed that the affinity of cultivated water chestnut and wild water chestnut was nearer than that between Lepironia articulata and Scirpus planiculmis. [Conclusion] The research provides theoretical basis for cultivating high-quality new varieties of water chestnut.展开更多
The genetic diversity of both wild and reared Pseudosciaena crocea (Richardson) collected from Guan Jing Yang in Ningde, China in May 1999 was investigated by random amplified polymorphic DNA (RAPD) in the present stu...The genetic diversity of both wild and reared Pseudosciaena crocea (Richardson) collected from Guan Jing Yang in Ningde, China in May 1999 was investigated by random amplified polymorphic DNA (RAPD) in the present study. The polymorphism and mean difference of the wild population as revealed by RAPD were 18.9% and 0.0960 respectively, and those of the reared stocks were relatively lower, with 16.7% in polymorphism and 0.0747 in mean difference. The genetic distance between the two stocks was 0.0041. From the comprehensive investigation, the main reasons for the loss of genetic diversity were probably overfishing, small number of parents as broodstocks and the debatable artificial ranching. Results from this study also showed that the large yellow croaker populations distributed along Fujian coastal waters including Guan Jing Yang still potentially wide genetic variability. It is suggested that genetic management and prevention should be scientifically conducted in order to maintain and improve the genetic diversity of the P. crocea population .展开更多
A comparative study on the phenotypic and genetic characteristics among Acidithiobacillus ferrooxidans (AF2), a typic strain ATCC23270 and a previously isolated strain AF3 was performed. AF2 can use ferrous ion (F...A comparative study on the phenotypic and genetic characteristics among Acidithiobacillus ferrooxidans (AF2), a typic strain ATCC23270 and a previously isolated strain AF3 was performed. AF2 can use ferrous ion (Fe^2+) or elemental sulfur (S^0) as sole energy source, but oxidizes So more effectively than Fe^2+, which is different from ATCC23270 and AF3. The G+C content of AF2 is 51.8% (molar fraction), however, ATCC23270 and AF3 strains have G+C content of 63.7% and 64.8% (molar fraction), respectively. The DNA-DNA hybridization results show that AF2 has 41.53% and 52.38% genome similarity to ATCC 23270 and AF3, respectively, but AF3 has a high genome similarity of 89.86% to ATCC 23270 strain. Rusticyanin (rus) and subunit III of aa3-type cytochrome oxidase (coxC) genes are not detected in AF2, but Fe^2+ oxidase (iro) gene can be detected. To understand the genomic organization of iro gene, a cosmid library of AF2 genome was constructed and iro gene-containing clone was screened. The sequencing result shows that although the nucleotide sequence of iro gene in AF2 is completely identical to that of ATCC 23270 strain, its genomic organization is different from that of ATCC 23270. In AF2, iro is located at downstream ofpurA gene, while it is located at downstream ofpetC-2 gene in ATCC 23270 strain. These results indicate that AF2 is a novel strain ofA. ferrooxidans, and that phenotypic differences among the strains ofA. ferrooxidans are closely correlated with their genetic polymorphisms.展开更多
基金Supported by Natural Science Foundation of Hubei Province(2005ABA084)Major Projects of Hubei Provincial Department of Education (04Z002)~~
文摘[Objective] The aim was to study the genetic diversities between Xiaogan water chestnut and wild chestnut with randomly amplified polymorphic DNA (RAPD) technology. [Method] Genetic diversities of the local cultivated water chestnut,wild chestnut,Lepironia articulata and Scirpus planiculmis Fr. Schmidt were analyzed by RAPD technology. [Result] Among the screened random primers 841,842,807 and 840,the polymorphism of amplification product of 841 was evident,and the obtained bands in electrophoresis were clear and showed good repeatability. Cluster analysis result showed that the affinity of cultivated water chestnut and wild water chestnut was nearer than that between Lepironia articulata and Scirpus planiculmis. [Conclusion] The research provides theoretical basis for cultivating high-quality new varieties of water chestnut.
文摘The genetic diversity of both wild and reared Pseudosciaena crocea (Richardson) collected from Guan Jing Yang in Ningde, China in May 1999 was investigated by random amplified polymorphic DNA (RAPD) in the present study. The polymorphism and mean difference of the wild population as revealed by RAPD were 18.9% and 0.0960 respectively, and those of the reared stocks were relatively lower, with 16.7% in polymorphism and 0.0747 in mean difference. The genetic distance between the two stocks was 0.0041. From the comprehensive investigation, the main reasons for the loss of genetic diversity were probably overfishing, small number of parents as broodstocks and the debatable artificial ranching. Results from this study also showed that the large yellow croaker populations distributed along Fujian coastal waters including Guan Jing Yang still potentially wide genetic variability. It is suggested that genetic management and prevention should be scientifically conducted in order to maintain and improve the genetic diversity of the P. crocea population .
基金Project(200805032) supported by the Scientific Research Program of Marine Public Welfare Industry of China
文摘A comparative study on the phenotypic and genetic characteristics among Acidithiobacillus ferrooxidans (AF2), a typic strain ATCC23270 and a previously isolated strain AF3 was performed. AF2 can use ferrous ion (Fe^2+) or elemental sulfur (S^0) as sole energy source, but oxidizes So more effectively than Fe^2+, which is different from ATCC23270 and AF3. The G+C content of AF2 is 51.8% (molar fraction), however, ATCC23270 and AF3 strains have G+C content of 63.7% and 64.8% (molar fraction), respectively. The DNA-DNA hybridization results show that AF2 has 41.53% and 52.38% genome similarity to ATCC 23270 and AF3, respectively, but AF3 has a high genome similarity of 89.86% to ATCC 23270 strain. Rusticyanin (rus) and subunit III of aa3-type cytochrome oxidase (coxC) genes are not detected in AF2, but Fe^2+ oxidase (iro) gene can be detected. To understand the genomic organization of iro gene, a cosmid library of AF2 genome was constructed and iro gene-containing clone was screened. The sequencing result shows that although the nucleotide sequence of iro gene in AF2 is completely identical to that of ATCC 23270 strain, its genomic organization is different from that of ATCC 23270. In AF2, iro is located at downstream ofpurA gene, while it is located at downstream ofpetC-2 gene in ATCC 23270 strain. These results indicate that AF2 is a novel strain ofA. ferrooxidans, and that phenotypic differences among the strains ofA. ferrooxidans are closely correlated with their genetic polymorphisms.