Hybrid sterility is a major hindrance to utiliz-ing the heterosis in indica-japonica hybrids. To isolate a gene Sc conferring the hybrid sterility, the locus was mapped us-ing molecular markers and an F2 population de...Hybrid sterility is a major hindrance to utiliz-ing the heterosis in indica-japonica hybrids. To isolate a gene Sc conferring the hybrid sterility, the locus was mapped us-ing molecular markers and an F2 population derived from a cross between near isogenic lines. A primary linkage analysis showed that Sc was linked closely with 4 markers on chro-mosome 3, on which the genetic distance between a marker RG227 and Sc was 0.07 cM. Chromosome walking with a rice TAC genomic library was carried out using RG227 as a starting probe, and a contig of ca. 320 kb covering the Sc locus was constructed. Two TAC clones, M45E14 and M90J01 that might cover the Sc locus, were partially se-quenced. By searching the rice sequence databases with se-quences of the TACs and RG227 a japonica rice BAC se-quence, OSJNBb0078P24 was identified. By comparing the TAC and BAC sequences, six new PCR-based markers were developed. With these markers the Sc locus was further mapped to a region of 46 kb. The results suggest that the BAC OSJNBb0078P24 and TAC M45E14 contain the Sc gene. Six ORFs were predicted in the focused 46-kb region.展开更多
文摘Hybrid sterility is a major hindrance to utiliz-ing the heterosis in indica-japonica hybrids. To isolate a gene Sc conferring the hybrid sterility, the locus was mapped us-ing molecular markers and an F2 population derived from a cross between near isogenic lines. A primary linkage analysis showed that Sc was linked closely with 4 markers on chro-mosome 3, on which the genetic distance between a marker RG227 and Sc was 0.07 cM. Chromosome walking with a rice TAC genomic library was carried out using RG227 as a starting probe, and a contig of ca. 320 kb covering the Sc locus was constructed. Two TAC clones, M45E14 and M90J01 that might cover the Sc locus, were partially se-quenced. By searching the rice sequence databases with se-quences of the TACs and RG227 a japonica rice BAC se-quence, OSJNBb0078P24 was identified. By comparing the TAC and BAC sequences, six new PCR-based markers were developed. With these markers the Sc locus was further mapped to a region of 46 kb. The results suggest that the BAC OSJNBb0078P24 and TAC M45E14 contain the Sc gene. Six ORFs were predicted in the focused 46-kb region.
