Abstract:

Amplified fragment length polymorphism (AFLP) analysis was used to reveal the relationships of species in Malus. A total of 72 samples representing 34 species, varieties, and hybrid species, and 38 cultivars were assayed. Six pairs of primer combinations selected from 64 combinations tested produced 1 692 legible loci, of which 1 547 (91.4%) were polymorphic. The genetic similarity coefficient among these 72 samples varied from 0.54 to 0.82. Four groups of taxa were assigned based on the results of cluster analysis with the genetic similarity coefficient at 0.60. First one was Malus florentina. The second contained the taxa of Sect. Choromeles. The third included the taxa of Sect. Docyniopsis. The taxa in Sect. Sorbomalus, Sect. Gymnomeles and Sect. Malusof Malus were clustered into the last group. All cultivars of apples and flowering crabapples distributed in the last group originated in Asia. The wild species in Asia played a very important role in the development of cultivars in Malus. A new section (Sect. Florentinae Cheng M. H.) was supported by the AFLP result. Sections of Sect. Sorbomalus and Sect. Gymnomeleswere suggested to merge into Sect. Malus (except Malus florentina) based on the results.

Key words: AFLP, Malus, classification, phylogeny