Genetic relationships among diverse spray- and standard-type chrysanthemum varieties and their derived radio-mutants determined using AFLPs

Gamma-ray irradiation is an important tool in ornamental plant breeding, particularly to induce flower-color variation. Standard-type chrysanthemum ‘Migok’ and spray-type ‘Argus’ have seven and four gamma-ray mutants, respectively, with novel flower colors. Genetic relationships among 26 chrysanthemum varieties or mutants were analyzed using amplified fragment length polymorphisms (AFLPs) with 20 fluorescently-labeled E+3/M+3 primer combinations (PCs). Clustering analysis was carried out using similarity coefficients and unweighted pair group method with arithmetic averages (UPGMA). The 20 PCs produced 2,837 bands, 95.6% of which were polymorphic. E-ACC/M-CAG had the most polymorphic bands (199) and high polymorphic information content, marker index, and resolving power values. Similarity coefficients ranged from 0.63 to 0.97 overall but were 0.73–0.83 in the 11 radio-mutants. The 26 varieties and radio-mutants were divided into four major UPGMA groups; the 11 radio-mutants formed two subgroups and 10 standard-type varieties or radio-mutants were closely clustered into another. The most promising mutant-specific marker candidates were PC E-ACG/M-CAG (47.5%) and E-ACA/M-CAT (44%) for the ‘Migok’ and ‘Argus’ families, respectively.