Analysis of Fitness Predominance for Gaoyou DuckÃÂs Double-Yolk Egg

One pair of recessive major gene and several modifiers dominated the major gene of Gaoyou duckÂ’s double-yolk egg. The fitness of double-yolk egg trait was analyzed by population genetics one the basis of special environment and natural geography. The results showed that the doubleyolk egg trait fitness was 8.23 under artificial selection during the year 2000 to 2002. The equilibrium of high intensive artificial selection and natural selection resulted in the trait of Gaoyou duckÂ’s double-yolk egg.