CHOI, KYEUNG* AND KI-JOONG KIM. Department of Biology, Yeungnam University, Kyeungsan, Kyeungbuk, Korea 712-742. - Molecular phylogeny of Quercus (Fagaceae): emphasizing the phylogeny of the Asian species.
The genus Quercus comprises approximately 500 species
distributed throughout the Northern Hemisphere. There are three major
distribution centers in the world including North America, Europe and
Eastern Asia. The Eastern Asia show the highest species diversity and
almost 250 species are recognized in this region. Many primitive
species of Quercus are also recognized in this region. In order
to elucidate the phylogeny and distribution patterns of the Asian
Quercus species, we reconstructed the phylogeny of the
Quercus species based on the three noncoding region sequences
of chloroplast genome and ITS sequences of nuclear rDNA. The combined
noncoding region phylogeny of chloroplast genome show the good
resolution among most species groups. However, the species
relationships among very closely related species were unresolved. The
phylogeny are more congruent to the geographical distribution patterns
of the species than the infrageneric classification system even though
the phylogeny largely congruent to the currently recognized subgenus,
section, and series. The ITS phylogeny also largely congruent to the
chloroplast DNA phylogeny, however, more than two copies of ITS
sequences are recognized from a same individual. We cloned and
sequenced two or three ITS types from several species. Thus, more
cautious data interpretation are required from the ITS sequences.
Key words: biogeography, chloroplast genome, phylogeny, Quercus, unclear ITS