Microsatellite marker analysis of an anther-derived potato family: Skewed segregation and gene-centromere mapping

Segregation patterns of polymorphic simple sequence repeat (SSR) primer pairs were investigated in monoploid potato families derived from anther culture. A total of 14 primers developed from the sequences in the database, as well as from a genomic library of potato, was used. Distorted segregation was observed for seven (50%) polymorphic loci among monoploids derived from an interspecific hybrid. Similar distortion was observed for only one of five loci that could be contrasted between the two monoploid families. Segregation distortion was less common in the sexually derived backcross population between the interspecific hybrid and either of its parents. One locus could be putatively linked to a lethal allele because it showed distorted segregation in both monoploid families, a group of 70 heterozygous diploids derived from unreduced gametes through anther culture, and a backcross population. These diploids were used to map the polymorphic SSR markers with respect to the centromeres using half-tetrad analysis. The majority of the SSR loci mapped more than 33 cM from the centromere, suggesting the occurrence of a single crossover per chromosome arm.