Abstract: PCR p rimerswere designed based on the conserved domain of some sucrose phosphate syn
thase genes in GenBank. The target cDNA fragmentwas amp lified from the total RNA isolated from melon fruit
of 25 days after pollination with RT-PCR and then was cloned into pMD18-T vector. The sequence showed that
the amino acid sequence encoded by this fragment showed a 98.9% similarity to that of the corresponding re
gion of sucrose phosphate synthase gene in tomato. The accession number of this gene in GenBank was
DQ355797. Northern blotwas performed to analyze the exp ression pattern of sucrose phosphate synthase in dif2
ferent development stages of melon fruit. The result showed that sucrose phosphate synthase began to exp ress
in fruit 25 days after pollination and the expression level of this gene increased with melon fruitmature.

Key words: Melon, Sucrose phosphate synthase gene, Cloning, Gene expression