The Study of B Chromosomes In Drosophila albomicans 2.The Reiation Between B Chromosomes and The Vitality of Kunming Population

The relation between B chromosomes and the vitality of Drosophila albomicans were analysed.The results showed that B chromosomes of D.albomicans serves two regulated functions during growth and development proecss.Their characters showed that B chromosomes exist inkaryotype of isofemale line as unitary shape,1B or 2Bs,that stimulate the action of growth and incresase the vitality on the one hand,and multiple B chromosomes exist to form the karyotype polymorphism resulted in restrictive action for growth and development on the other hand.