Study On Insemination Biology In Hybridization Between Oreochromis Aurea (♀) And Siniperca Chuatsi (♂), And Studies On Karyotypes Of Their Offpring

1. Study on insemination Biology in hybridization between Oreochromis aurea (♀)and Siniperca chuatsi( ♂ )The insemination biology in hybridization between Oreochromis aurea (♀ )and Siniperca chuatsi ( ♂ ) reveals that the sperm of S. chuatsi can enter the egg cytoplasm of O. aurea, then grow into spermaster and finally form the male pronucleus. After a while, the female and male pronucleus contact and fuse each other, and ultimately become zygote nucleus. Although the hybridization between O. aurea (♀ ) and S. chuatsi (♂) is distant hybridization, this study shows that the whole process obeys the normal fertilization process and egg splits. Observing the embryonic development of the hybrid and its parents(Oreochromis aurea and Siniperca chuatsi ), we discover that the embryonic development rate of the hybrid is much closer before the early-blastula and is little slower in the late-bias tula to that of O. aurea, but is considerably different to that of S.chuati.2. The search for the blood lymphocytic cell cultivation of the tilapia and the preparation of chromosomesGet blood from the vein under lateral line scales of tilapia by injection syringes with depo-heparin. Use the whole culture medium of RPMI1640 to culture the blood cell in vitro. With researching the inoculation time after get blood ,the content of colchicines and adding time ,permeating time and temperature and so on ,establish a set of fairly matural experimental method to cultivate the blood lymphocytic cell of the tilapia. The result showed that the blood cell was cultivated in CO2 incubator under a temperature of 30° C for 72-96h . Colchicines were added until it reached concentration of about 0.05ug/ml working for 2-3h before the end of cell cultivation, and the lymphocytes were permeated for 30 minwith KCL. The good chromosome specimens were prepared by the routine methods of hypotonicity ,fixing and coloration. And it would get good chromosome yet when the blood cell was reserved for about 10 days in 4℃ refrigeerrator.3. Studies on karyotypes of Oreochromis aurea (♀) Siniperca chuatsi (♂) and their offpringThrough several years' research ,we successfully obtained the progenies of the distant hybridization between Oreochromis aurea (♀ )and Siniperca chuatsi (♂ ).And their karyotypes were studied. The result obtained indicate that the diploid chromosome number of O.aurea (♀) is 2n =44,chromosome fomula :6sm+24st+14t,arm number (NF)=50;the diploid chromsorne number of S.chuatsl ( ♂ ) is 2n=48,chromsome fomula: 8sm+4st+36t,NF=56; the diploid chromsome number of their progenies is 2n=44,chrosome fomula :6sm+26st+12t,NF=50.The result of comparison is that they are quite close to each other in terms of classification status.