The Investigation Of Bothriocephalus Acheilognathi Infection And The Analysis Of Mitochondrial Gene Sequences Cox1 Of Water Area Around Dongting Lake

In order to provide a scientific basis for the control of Grass Carp Bothriocephalosis acheilognathi,this research investigated not only the infection of Grass Carp Bothriocephalosis acheilognathi at the farmer’s markets around Dongting Lake, but also the morphological observation and molecular identification of grass carp tape-warms,In the second chapter, the researcher explores tentatively on the morphological observation of Grass Carp Bothriocephalosis acheilognathi. Through the settings of different time of tablet press,dyeing, and dehydration,namely the carmine stain method, the outcome is that the most effective mode is specimen tablet pressing for 4 days,dyeing for 6hours and dehydrating for 30 minutes.In the third chapter of this paper, the investigation result is demonstrated to illustrate the infection status in the regions around Dongting Lake, such as Ningxiang, Yiyang, Yueyang, and Changde. As is shown in the result, the general infection rate is 7.14%, with the infection intensity ofl-104/unit.The intestines of the infected grass carps are seriously clogged and congested with clusters of severe infection.Thus, it can be concluded that the Grass Carp Bothtiocephalus acheilognathi exerts great hazard extents on grass carps.The fourth chapter deals with the sequence analysis on the coxl genes of the mitochondria of Grass Carp Bothtiocephalus acheilognathi at the six places.Through the analysis, the length of gene fragment was 448bp, with the intraspecific similarity all over 97.2%, whereas the interspecific similarity all lower than 73.5%.As is displayed on the germ-line development tree constructed by NJ method,homogeneity is situated on the same branch, which is separated from the branches of other Grass Carp Bothtiocephalus acheilognathi. The result agrees with the that of the morphological observation. It indicates that the analysis method based on the germ-line of coxl gene renders a result more accurate than other methods. Therefore, coxl genes can be used as reliable marks of molecular genetics of Grass Carp Bothtiocephalus acheilognathi.It is the first time that infectious status of the farmer’s markets around Dongting Lake is comprehensively and systematically investigated and molecular biology of Grass Carp Bothtiocephalus acheilognathi is studied, which lays a solid foundation for the classification,identification,diagnostics,molecular epidemiology and phylogenetics of Grass Carp Bothtiocephalus acheilognathi.