Genetic Composition And Nutrient Analysis Of The Progeny Of Female F₁Hybrid （Blunt Snout Bream×Topmouth Culter）×Male Blunt Snout Bream

BTB is a new type of hybrid fish of BT (♀) and Blunt snout bream (♂), BT refers to diploid female fertility hybrid individuals (blunt snout bream♀×topmouth culter♂) in heterologous hybrid strains between Blunt Snout Bream (abbr. BSB) and Topmouth Culter (abbr. TC). This research investigates45S rDNA ITS sequences of BTB and the chemical composition of muscle nutrients of BTB, TC, BSB, BT. Analyzes results in this study include content of moisture, fat, protein, ash, and carbohydrate, as well as calorific value, fatty acid composition and amino acid composition.、45S rDNA ITS sequences of BTB are cloned and compared with their parents. Using specific primers for amplification, we get the sequence of BTB’s5.8S, ITS1and ITS2sequences. The amplified BTB45S rDNA ITS sequences fragments of different sizes come from BSB and TC. Comparative sequence analysis shows that there are base deletion, duplication and substitution in BTB ITS sequences, which shows hybridization may lead to the occurrence of a certain BTB genetic variation.2、By nutritional analysis of BTB, TC, BSB and BT, we find BTB as omnivorous fish has no nutritional value lower than TC. Compared to other three species, we observed that BTB has a lower fat and higher water content (p<0.05). In terms of protein, BTB has greater protein content than three other kinds. The total amount of carbohydrate is significantly lower than the other three kinds of fish (p<0.05). we also observed that BSB, TC, BT, BTB has a similar content value of the total energy.3、Through the fatty acid composition analysis with the meteorological MS, we find BTB muscle fatty acid data are higher than the BSB and BT. As hybrids of BSB and TC, the data of BT is basically between the two fishes; while hybrid BTB is closer to TC fatty acid composition and some of the data was significantly higher than it. Four fish both have a high proportion of unsaturated fatty acids. In oleic acid, a-linolenic acid (ALA), EPA, DPA, DHA, etc., this content advantage of BTB is the most significant. BSB has a higher total CLA content than the other three fish.4、Using amino acid hydrolysis, the amino acid composition levels of17kinds are measured. BTB abundant amino acids and has a high proportion of the amino acid flavor compared with their parents and indirect parent.The above results provide evidence of biochemical aspects to prove that BTB is a fish with good taste and high nutritional value quality. In fisheries development, BTB as a new hybrid with extensive promotion and application value, proved that built distant hybridization and heterologous strains is indeed an effective tool to integrate existing natural species, fast cultivate more excellent traits, richer variety of new hybridization of fish.