Analysis of Introgressed Segments in Near isogenic Lines for F1 Pollen Sterility in Rice (Oryza sativa)

One hundred and fifty eight microsatellite markers showing polymorphism among parents were used to survey the introgressed segments in the 50 near isogenic lines of F1 pollen sterility. Two hundred and sixty introgressed segments were detected in 50 near isogenic lines, each carrying 5.2 introgressed segments on an average. Among the 260 segments, one hundred carrying F1 pollen sterility loci concentrated on the region of F1 pollen sterility genes, and the remaining one hundred and sixty without F1 pollen sterility loci distributed randomly over 12 chromosomes. Both the average number and length of the introgressed segments decreased along with the increase of backcross generations. The number of introgressed segments was less than four and the length was less than 20 cM in the near isogenic lines after backcrossing for four or more times.