Fast and Simple Monitoring of Introgressive Gene Flow from Wild Beet into Sugarbeet

Weed beet, so-called bolters, can arise either from self dedomestication of sugarbeet or from hybridisation with wild sea beet relatives. Previous investigations indicated that weed beet may evolve from hybridisation between wild and cultivated beet when they occur in close proximity. Beet seed can persist several years in soil allowing the formation of a seed bank that subsequently releases weed beet again. Microsatellite markers were used to trace hybridisation events within weed beet populations from 12 fields in Brandenburg, Germany. Seeds derived from bolter offspring were analyzed at three microsatellite loci and population allelic patterns were compared with sugarbeet varieties and wild beet as reference genotypes. The results demonstrate past hybridisation and introgression of wild beet alleles, even in the seeds of the bolters. The use of only three highly polymorphic microsatellites provides a simple and fast method to monitor individuals for feral or wild beet characters that may cause adverse effects if recombination with GM beets were to occur.