Received: August 31, 2011 Revised: September 15, 2011 Accepted: September 19, 2011
Abstract
Various aneuploidy and polyploidy have been reported in the genus Aconitum L. (ca. 300 species worldwide, Ranunculaceae), and there is a demonstrated association between major lineage diversification and polyploidy. This study reports chromosome counts of eight Aconitum from Korea, including the first counts for A. japonicum Thunb. subsp. napiforme (H. Lev. & Vaniot) Kadota (2n = 32) and A. longecassidatum Nakai (2n = 16). The study also includes chromosome numbers for two taxa on the Critically Endangered species list in Korea. Among Korean native species, chromosome numbers in Aconitum subgenus Aconitum range from 2n = 16 to 2n = 64 with diverse levels of polyploidy (2x, 4x, and 8x), whereas Aconitum subg. Lycoctonum exhibits only diploids (2n = 16). Greater chromosome number diversity in subg. Aconitum than subg. Lycoctonum might explain higher species diversity within the former subgenus (more than 250 species worldwide). Investigating chromosome number diversity of Aconitum in a phylogenetic framework will be a critical step to understand species richness of the genus.