Cytological Study of Begonia Sections Jackia, Platycentrum and Reichenheimia (Begoniaceae) with Chromosome Numbers 2n=34 and 38

Previous chromosome information for 2n=34 and 2n=38 is restricted to one species in the Asian Begonia sect. Jackia with 2n=34, and six species in sect. Platycentrum with 2n=38, respectively. We present here the first chromosome counts of two species B. sublobata and B. emeiensis with 2n= 34 in respective sections of Jackia and Platycentrum and one species B. chingii with 2n=38 in sect. Reichenheimia, and the first karyotype analyses of them as well as two re-examined species of B. chitoensis and B. myanmarica with 2n= 38 in sect. Platycentrum. We discussed the chromosome evolution of 2n= 34 and 2n= 38 in Asian Begonia sections Jackia, Platycentrum and Reichenheimia.