Data from: Karyotype and genome size variation in genus Ajuga L. (Ajugoideae–Lamiaceae)

Chromosome number changes and karyotype evolution play an important role
in plant genome diversification and eventually in speciation. The genus
Ajuga L. (Lamiaceae) has approximately 50 species distributed in temperate
to subtropical regions. Four of these species are currently recognized in
Korea (A. decumbens Thunb., A. multiflora Bunge, A. nipponensis Makino and
A. spectabilis Nakai). Understanding the karyotype evolution in Ajuga has
been hampered by the small size of their chromosomes and symmetrical
karyotypes. Here we used classic Feulgen staining to establish chromosome
numbers and construct karyotypes of the four species of Ajuga recognized
in Korea and flow cytometry was used to study their variation in genome.
The chromosome number of all investigated plants was 2n = 32. Still, the
2C DNA content ranged from 2.18 pg (A. decumbens) to 4.53 pg (A.
multiflora). While the chromosome numbers were the same for all
investigated species, the genome size variation could potentially be used
as a taxonomic marker.