Abstract：A Newcastle disease virus field strain PB9601 was isolated from a pigeon in Beijing which can form typical pathological changes through regression experiment after plaque-purification. NDV PB9601 was determined as a virulent strain with MDT of 50.5h , ICPI of 1.65, IVPI of 2.36 respectively. The F and HN gene were cloned and sequenced. The sequence analysis of F gene indicated that the amino acid sequence is 111 KRQKRF 117 in the F protein cleavage site in PB9601 strain which is identical to virulent strains of NDV. The homology analysis of F and HN gene sequences compared to reference isolates from GenBank indicated that: PB9601 belongs to genotype VI with YN-03 and TW-98；The F protein amino acid sequence has homologies of 88.6%,91.0%,90.6% with LaSota,V4,F48E9 and of 92.1%, 95.5%, 98.6% with isolates GX-05,YN-03,TW-98 in China and of93.3%、91.9%、94.6%、95.1%、93.6% with isolates Capital3-97、Tigre6-99、1166-00、IT-227-82、2736-00 abroad. When HN genes were compared, PB9601 demonstrated higher homologies of 91.9%, 93.3%, 94.6%, 95.1%, 93.6% with isolated strains Tigre6-99, Capital3-97, 1166-00, IT-227-82, 2736-00 abroad , but lower homologies of 87.2% ,89.2%, 87.6% with LaSota , F48E9 and V4.The above results show PB9601 has obvious regional and genus traits compared with isolated strains LaSota ,F48E9 and V4 .
