Investigate the genotypic basis of an observable phenotype using Rapid Cycling Brassica rapa (RCBr), also known by the trademark name Wisconsin Fast Plants. Wild-type plants grow with a distinctive purple stem due to the pigment anthocyanin. In some RCBr plants, a mutation disrupts the anthocyanin production pathway and leads to green stems. The gene responsible for the purple vs. green color is named Anthocyaninlessbecause the mutant form leads to decreased production of the pigment anthocyanin. Test the Anthocyanin gene from different plants to link genotype to phenotype.