[Comparison of genetic linkage maps based on F2F6 populations derived from rice subspecies cross]

A F2 population containing 180 lines, which was derived from the cross between the partially sequenced indica variety "Pei'ai 64S" and the completely sequenced japonica variety "Nipponbare" , was used to construct a genetic linkage framework map (referred to as F2 map), which included 138 microsatellite sites and covered 1737.81 cM of total genomic length, an average distance of 11.90 cM. Single seed descent F2:6 population with 330 lines was used to construct a genetic linkage map (known as F6 map) using 92 markers. The total genomic length and average distance were 2563.5 cM and 27.86 cM, respectively. The F2 and F6 maps differed in linkage groups, mapped markers, sequenced order of markers, ge-netic distance and average distance on the maps. Preliminary analysis about these difference was carried out.