Physical Location of Rice Gm-6, Pi-5(t) Genes in O. officinalis with BAC-FISH

A fluorescence in situ  hybridization (FISH) procedure was adopted to physically map two rice BAC clones 24E21 and 4F22 linked to Gm-6  and Pi-5(t)  in O. officinalis . FISH results showed that the two BAC clones were located at 4L. The percentage distance from the centromere to the hybridization sites was 72±2.62 for 24E21 and 54±5.43 for 4F22, the detection rates were 52.70% and 61.2%. The results obtained from the BAC and plasmid clones, RG214 and RZ565 of cultivated rice and O. officinalis  were the same. This suggested that the markers, RG214 and RZ565 of cultivated rice and O. officinalis  were in the same BAC clones. The homologous sequences of Gm-6  and Pi-5(t) in O. officinalis  were positions that signals existed on the 4L. Many signals were observed when no Cot-1 DNA blocked. This also showed that repetitive sequences were some homolgous between cultivated rice and O. officinalis . The identification of chromosome 4 of O. officinalis  is based on Jena et al. (1994). In our study, we discussed the possibility of physical map in O. officinalis  with rice BAC clones.