Abstract:

A cDNA library was successfully constructed via suppression subtractive hybridization between fruit epicarp (experimental group, tester) and pulp (control group, the driver) of Ponkan(Citrus reticulata Blanco). Results showed that most of the clones had inserting fragments which length ranged from 100 bp to 500 bp. Four hundred and eleven ESTs were successfully sequenced and searched against NCBI GenBank, The results indicated that 377 ESTs had significant similarities with known genes. All the ESTs were divided into 126 genes according to the gene annotation. These ESTs were mainly involved in pigment synthesis, energy metabolism, primary metabolism, secondary metabolism, defense against stresses, signal transduction, transcription, flavor formation, oil synthesis, peel softening, antioxidant metabolism et c. There were 63 uni-ESTs which accounted for 49.2% of the total ESTs and another 34 ESTs had no matching homologous sequences found.

Key words: citrus, suppression subtractive hybridization(SSH), cDNA library, expressed sequence tag, clone, differentially expressed genes