Abstract: To investigate the characteristics of the S gene in almond, we degenerative primers according to conservative sequence of S gene in rosaceous plant and got 10 S gene fragments by PCR application from 8 almond cultivars in China. All sequenceswere aligned with S genes in GeneBank by BLAST software. The result indicated that all 10 fragments contained domain encoding 5 high conservation regions (C1, C2, C3, RC4, C5) and hypervariable region (RHV) of rosaceous S2RNase . RHV and intron characterized S gene furthermore. Homology analysis showed that the amino acid sequence between putative peptides from above S gene fragments and that from S-RNase of rosaceous p lant were 67% - 96% of homology. Almond should be assigned to plum subspecific group s with cherry and apricot.

Key words: Almond, Self-incompatibility, S gene, PCR, Sequence