Genetic relationship and genetic diversity among Typha taxa from East Asia based on AFLP markers

The genetic relationship and diversity among four Typha taxa in East Asia were evaluated using amplified fragment length polymorphism (AFLP) markers. Three AFLP selective primer combinations generated a total of 707 amplification products, of which 704 (99.6%) were polymorphic. The unweighted pair-group method with arithmetic mean (UPGMA) dendrogram and principal component analysis (PCA) plot confirmed the taxonomic status of four separate species. East Asian Typha taxa separated into two groups: the first with Typha angustifolia and the second with T. orientalis, T. laxmanni, and T. latifolia with a high bootstrap value for UPGMA (93%) and a low first score for PCA (25%). The two clusters corresponded with two sections based on the bracteoles in the female flower: section Bracteolatae and section Ebracteolatae. T. angustifolia showed the highest genetic diversity among the four Typha taxa (percentage of polymorphic loci [PPL] = 71%, H_o = 0.157), whereas T. latifolia had the lowest genetic diversity (PPL = 40%, H_o = 0.117). Genetic diversity was related to the presence of the gap between male and female inflorescences. A positive correlation between genetic distance and geographic distance was clearly found in the two species with continuous inflorescences (T. latifolia and T. orientalis). This positive correlation was not observed in the other species with discontinuous spikes (T. angustifolia and T. laxmanni).