The Application Of Distant Hybridization In The Variety Improvement Of Tilapia And Study On Biological Properties Of F1 Progeny

Using hormone to stimulate blue tilapia to ovulate, the breakthrough of artificial propagation of blue tilapia brought mature eggs. These mature eggs fertilized with the sperm of mandarin fish and obtained hybrids Fl. The embryo development of hybrids Fl was same as the control before Middle stage of gastrula. After Middle stage of gastrula, the hybrid embryo development slow or stop. Most of them had Haploid syndrome and died. Only about 2%o fry lived.Genetic relationships between the parental fishes blue tilapia^ mandarin fish and their hybrids Fl were assayed with RAPD technique using 32 random primers, of which 16 random primers generated obviously amplified products. About 401 DNA bands were observed with 11 primers both in the checked parents and the offspring. There exit 1 to 7 DNA bands being amplified with single primer in each sample, and the sizes of them were varied from 200bp to 3500bp. In 11 random primers, there are 3 primers amplified 3 special bands to identify that the Fl progeny was the result of allogynogenesis. The genetic similarity rate was 91.30% among the Fl progeny and the Fl progeny was 85.77% similar to mother tilapia and 4.87% to father mandarin fish. Genetic similarity indices demonstrated that the offspring of blue tilapia(♀) X mandarin fish(♂) were extremely similar to blue tilapia, at the same time, it is revealed on gene level that the Fl does not undergo complete maternal heredity, and the Fl has probably inherited some paternal genome DNA.