Karyology of Ten Species of Impatiens (Balsaminaceae) from SW. Yunnan, China

Abstract

Ten species of Impatiens collected from southwest Yunnan were examined karyologically. Eight of them were analyzed for the first time. As a result, five different chromosome numbers were counted : 2n=12 in I. aureliana; 2n=16 in I. begoniifolia, I. mengtszeana, I. yingjiangensis; 2n=17 in I. mengtszeana; 2n=18 in I. racemosa, I. ruiliensis, I. siculifera, I. tongbiguanensis, I. uliginosa; 2n=20 in I. rubrostriata. No significant difference in karyotype was found among species with the same chromosome number. The karyotypes of species with 2n=12,2n=17,2n=18,and 2n=20 are bimodal, while those with 2n=16 are monomodal. On the basis of these karyological characteristics, relationships of these Chinese species to other species occurring in adjacent regions are discussed.