Gene clone and sequence analysis of 18S ribosomal DNA of Helicoverpa assulta (Guenée).

The complete nucleotide sequence of 18S rDNA gene from Helicoverpa assulta (Guenee) was cloned by PCR and its full length was 1904bp. The phylogenetic trees based on the full length, conserved regions and non-conserved regions of 18S rRNA gene were constructed and the homology of the full length of 18S rDNA gene with those of other known moths was compared. The result showed that the homology was above 92% on the 18S rDNA gene among moths. The phylogenetic tree constructed based on the variable regions could reflect the real evolving relationship of moths. The difference between Hass18S rDNA and Helicoverpa armigera (Hubner) 18S rDNA was only in 10 nucleotide acids.