Application of isozyme electrophoresis for purity testing and cultivar identification of F₁ hybrids of Brassica oleracea

Six isozyme genes were analyzed in seed samples of 65 commercial F₁ hybrids of four horticultural groups of Brassica oleracea (cabbage, Brussels sprouts, sprouting broccoli and cauliflower). Results obtained from electrophoretic assays led to the following conclusions: 1) the electrophoretic test of F₁ hybrid purity was possible in 59 (91%) of the hybrids analyzed, since their inbred parents were apparently fixed each for a different allele in at least on of the loci studied; 2) forty-eight (74%) of the hybrids were individually distinguished by their isozyme phenotype; 3) high levels of segregation in the inbred parents were inferred from the analysis of a sample of seeds of each hybrid.