Phylogenetic relationships of Begonia with emphasis on the Chinese species--Evidence from ITS sequences
Begonia is the largest genus of the family Begoniaceae, with approximately 1400 species widely distributed throughout the tropics (see Shui et al, 2002). Many Begonia species are commonly cultivated ornamental plants. The genus is divided into 63 sections with approximately 150 species occurring in China. Early classification divided the 51 Chinese species known at the time into 6 sections (Irmscher, 1939). This scheme was revised by subsequent authors at different times as the species number increased, resulting in highly incongruent classification for the Chinese species (Yü 1948; Liou 1983; Ku 1999; Shui et al. 2002).

The most recently scheme recognized nine sections for the 150 Chinese species (Shui et al 2002). The taxonomic controversy on the Chinese Begonia is largely due to the lack of knowledge of phylogenetic relationships among the species. Understanding species relationships is not only critical in classification, but also important to biologists interested in other biological researches of Begonia.

In the present study, we are conducting a comparative DNA sequencing study of the internal transcribed spacer of nuclear ribosomal gene (ITS) to infer phylogenetic relationships among Begonia species.