The Research Of Molecular Genetics About Carassius Auratus In Qihe River By ISSR And Cytb

Carassius auratus in Qihe River belonged to Cypriniformes,Cyprinidae ,Carassius Jarocki, which was the natural gynogenesis triploid crucian and produced in Henan province. It is very famous for its rapid growth, excellent taste and high benefits with rosy prospect. Just as these unique features of C.auratus in Qihe River, lots of scholars were interested in the research of its molecular genetics, evolution genetics and so on. This research adopts ISSR and Cytb techniques to analyse genetic diversity and genetic distance among C.auratus in Qihe River and the other C.auratus in wild which in order to konw about genetic evolution and the relations among others near species of C.auratus in Qihe River.According to this research we can offer the theoretical basal for the germplasm resources and genetic breeding.1. ISSR analysis of genetic diversity among C.auratus in Qihe River and the other two C.auratus populations in wildThe study about the genetic diversity of 3 populations which were C.auratus in Qihe River, C.auratus in Jindihe River and C.auratus in Qinhe River by using Inter-Simple Sequence Repeat(ISSR). The results were as follows: (1) A total of 94 discernible DNA fragments were observed by 8 primers analysed,among which 82 fragments being polymorphic, The percentage of polymorphic was 87.23%. (2) The genetic diversity of the population in C.auratus in Qihe River was comparatively low calculated in POPGENE, PPB was 61.70%, H of 0.2036, I of 0.3085. (3) The inter-populations Nei's genetic differentiation coefficient and gene flow were 0.1303 and 3.3359 respectively, indicating that the genetic differentiation among three populations had not reached the population level yet. (4) C.auratus in Jindihe River and C.auratus in Qinhe River stocks had the genetic distance relatively nearby, and C.aurutus in Qihe River stock had a degree of genetic differentiation and formed the genetic structure which was stable and independent.2. Genetic analysis of Cytb among C.auratus in Qihe River, eight C.auratus populations in wild and others near species of C.auratusMitochondrial DNA cytochrome b (Cytb) gene was amplified by PCR and sequenced bidirectional in C.auratus in Qihe River and eight C.auratus populations in wild. The results showed that there were no differences in sequences among the nine populations and the sequence was about 1140bp in full length. The Cytb gene sequence of C.auratus in Qihe River and the other six populations had no variation with the exception of C.auratus in Jiuli Lake and C.auratus in Datanggang Reservoir.The Cytb gene sequence of C.auratus in Qihe River contained 29.1%, 27.9%, 28.6%, 14.4% of T, C, A and G, respectively.The result of C.auratus in Qihe RiverA+T(57.7%) > G+C(42.3%) was similar to that in other seven populations with the exception of C.auratus in Jiuli Lake. The Cytb gene sequence of C.auratus in Qihe River showed that the bases had a obviously bias and had low content of G(14.4%), in the first position of codon only contained 9.3% and the third position of codon contained 14.0%, the second position basically did not have bias. The other eight populations also had the same features.The result of phylogenetic tree constructed by Neighbor-Joining method indicated that C.auratus in Qihe River had the closest phylogenetic relationship with the common C.auratus, had the second distance with C.auratus var. Pingxiangnensis, had far distance with C.gibelio in Japan, C.gibelio in Greece, C.langsdorfii in Japan and C.langsdorfii in Czech Republic, had the farest distance with C.carassius.