Cloning and Sequence Analysis of Candidate Disease Resistance Genes from Dongxiang Common Wild Rice (O. rufipogon Griff.)

A strategy is described here for isolation of candidate disease resistance (R) genes from Dongxiang common wild rice (O. rufipogon Griff). This method integrates the techniques of candidate gene analogs cloning, the construction of wild rice transformation competent genomic library and the R gene enrichment library, the colony in-situ hybridization experiment, and the sequence analysis of function genes. In this research, a transformation competent genomic library with a volume of 1.58 x 10(5) clones was constructed for Dongxiang common wild rice and an enrichment library of R genes was further constructed with a volume of 3072 clones, from which 17 positive clones were isolated. The end-clone sequencing of 9 representative positive clones reveals that 6 can be located at or near to the existed R genes or the predicted R genes. Sequences analysis of 6 clones suggests that 5 contain the conserved domain of R genes, indicating the strategy is feasible and simple to clone new R genes from wild rice species.