Congener species with incomplete reproductive barriers that coexist along environmental gradients may be prone to ecological divergence, in spite of the potential for hybridization in sympatry. We analyzed distribution patterns of isozymes, plastid, and nuclear DNA sequences at regional and local scales in three timber Cedrela species of the subtropics in the northern Argentina (Cedrela angustifolia, C. balansae, and C. saltensis), to test whether populations of distinct species have diverged in montane habitats in relation to their ecological characteristics. Cedrela balansae and C. angustifolia can be identified by diagnostic isozyme alleles. Nuclear ITS sequences yielded intraindividual polymorphism; ambiguous bases were shared between C. balansae and... |