Abstract:Genetic construction of wheat germplasms resistant to BYDV (Barley Yellow Dwarf Virus)were analyzed by Genome In Situ Hybridization (GISH),the results showed that:(1)Wheat /Thinopyrum intermedium a partial amphiploid Zhong 4 awnless (2n=56) have 20 pairs of wheat chromosomes,five pairs of Th. inte