Morphological characteristics and AFLP markers for classifying an Italian genepool of evergreen azaleas

In the present study, a morphological and genetic characterisation was carried out to investigate origins, classification and diversity of evergreen azaleas grown in historical gardens and nurseries of the Lake Maggiore area (Northern Italy). Ninetythree genotypes (locally classified in the groups Indica, Japonica and Amoena) were described by means of 10 variables referring to flower and leaf morphology and were DNA-typed by means of the AFLP technique. Eighty-four species and cultivars, chosen among distinguishable groups within the evergreen azaleas (Belgian, Hirado, Kurume and Satsuki), were also included in this study as a reference for classification to reveal the origins of the Italian accessions. Similarities of the fingerprint patterns were evaluated as an estimate for genetic conformity and for relatedness performing ordination analyses (UPGMA clustering and PCO). Morphological and AFLP data were compared by means of the Mantel test. Assignment tests both on the level of the groups as on individual plant level for the reference and Italian genotypes were applied to evaluate further the relatedness of the groups or individual accessions. Results demonstrated that the AFLP technique together with morphological characterisation could be a useful tool for clarifying the origin and classification of evergreen azalea genepools. Comparing the reference and Italian genotypes, conclusions about the classification of the evergreen azalea cultivars located in the Lake Maggiore area could be drawn.