[Construction of a microsatellite linkage map in a DH population]

A doubled haploid population (DH) consisting of 86 lines derived by anther culture of Peiai64s/E32, a two-line hybrid rice variety with high heterosis, was used to construct a microsatellite or SSLP linkage map of rice chromosomes. A total of 302 PCR primers for SSLP analysis on these chromosomes were chosen from a map published by Cornell University (designated CUMAP) and 127 (42.05%) of them were found polymorphic between the two parents. Those polymorphic PCR primers were used for population genotyping. The map (designated PEMAP) comprises 122 microsatellite maker loci,covering a total length of 1213.4 cM. The PEMAP is highly comparable with the CUMAP. Most of the markers were mapped onto the same chromosomes and aligned in the same order. Serious segregation distortion was observed in this DH population,with 34 (27.8%) markers showing significant deviation. It is noted that all markers on chromosomes 1,3,10 and 11 were biased to Peiai64s, while those on chromosomes 4,6,7,8 and 9 were opposite.