A Comparative Study of the Karyotypes from Four Egg—type Fowl Breeds

By adopting the method based on colchicines-hypotonic-air drying technique with bone mar-ro cells,the paper presents the chromosome of four egg-type fowl breeds.The diploid chromosome 2n-78,chromosomal morphology are very similar and sex chromosome type are ZZ(♂)and ZW(♀) in four egg-type fowl breeds.Accrding to standard of Leven in 1964,the euchromosome and sex chromosome of four breeds are measured and compared in relative length arm ratio and centromere index of each chromosome including all the microchromosome.The morphology of these chromosome is described as follows:pair1,2,8 and ZW are metacentric,pair 4 and 6 are submetacentric,and the rest is telocentric.