Isolation and Genetic Polymorphism Analysis of Pear SFBB super(-g) Genes

By using PCR-based molecular method, four new pear SFBB super(-g) genes were isolated from 8 pear cultivars known as S-genotypes. Length of PCR products from eight pear cultivars was around 1 200 bp. Sequencing the specific PCR fragments revealed four new SFBB super(-g) genes that were respectively named as SFBB super(16-g) (EU422956), SFBB super(17-g) (EU422957), SFBB super(28-g) (EU422960) and SFBB super(35-g) (EU422958). As for different SFBB super(-g) genes, variation in amino acid was higher in F-box region and variable region 1, and lower in variable region 2 to 4. Phylogenetic analysis showed that there was a high level of difference between Japanese pear (Pyrus pyrifolia) SFBB super(-g) genes and Xinjiang pear (P. sinkiangensis) SFBB super(-g) genes, as well as Japanese pear SFBB super(-g) genes and Chinese white pear(P. bretschneideri) SFBB super(-g) genes. The results might reflect their genetic relationships among the species.