Based on Southern blot hybridization at low stringency using the Autographa califonica nuclear polyhedrosis virus( Ac NPV) p 74 gene as heterologous probe( Eco RⅠ fragment P of Ac NPV DNA containing partial p 74 gene)

the p 74 gene of Spodoptera litura NPV( Sl NPV) were localized on the XhoⅠ fragment P (4 900 bp) of the physical map of the viral genome. A 938 nt fragment( Bam HⅠ Eco RⅠ) of Xho Ⅰ fragment P was subcloned and sequenced. Two fragments

243 nt and 81 nt

from the determined sequence

shared 60% and 79% nucleotide identity with Ac NPV p 74 gene respectively. Another two fragments

264 nt and 100 nt

shared 60% and 71% nucleotide identity with Choristoneura fumiferana NPV( Cf NPV) p 74 gene respectively. Partial sequence of the 938 nt fragment showed 58%￣78% nucleotide sequence homology to Bombyx mori NPV( Bm NPV) and Orgyia pseudotsugata NPV( Op NPV) p 74 genes. Amino acid sequence encoded by the partial determined nucleotide sequence shared high amino acid sequence similarity with Ac NPV and Op NPV P74 proteins. The results indicate that the partial sequence of the 938 nt fragment is the Sl NPV P74 protein coding sequence.