Abstract: Chromosome numbers and karyotypes of 10 wild bramble (Rubus L. ) species ( varieties) from Southwest of China had been studied by using common root-tip squashing method. The results showed that they were all diploidy with 2n = 2x = 14, but R. buergeri with 2n = 8x = 56, R. lambertianus var. glaber,
R. multibracteatus and R. setchuenensis with 2n = 4x = 28, and R. parvifolius with aploidy series of 2n = 2x = 14, 2n = 3x = 21 and the mixoploid of 2n = 4x = 28 and 2n = 2x = 14. The results showed also that all the karyotypes belonged to “1A”type, but“2A”type in R. ellipticus var. obcordatus, their karyotype formulae were as follows: R. niveus, 2n = 2x = 14 = 14m; R. ellipticus var. obcordatus, 2n = 2x = 14 = 12m (2SAT) + 2 sm (2SAT) ; R. parvifolius, 2n = 2x = 14 = 14m (2SAT) , 2n = 3x = 21 = 21m (3SAT) , 2n = 4x = 28 = 24m + 4 sm (4SAT) and 2n = 2x = 14 = 12m + 2 sm (2SAT) ; R. am abilis, 2n = 2x = 14 = 12m ( 2SAT) + 2 sm; R. coreanus, 2n = 2x = 14 = 14m (2SAT) and 2n = 2x = 14 = 14m; R. corchorifolius, 2n = 2x = 14 = 14m; R. lambertianus var. glaber, 2n = 4x = 28 = 24m + 4 sm; R. multibracteatus, 2n = 4x = 28 = 24m + 4 sm; R.setchuenensis, 2n = 4x = 28 = 28m; R. buergeri, 2n = 8x = 56 = 56m. Among them, it was reported firstly that the chromosome numbers of two species R. ellipticus var. obcordatus and R. amabilis, the mixoploid forms of 2x and 4x in R. parvifolius and karyotypes of the 8 species R. niveus, R. ellipticus var. obcordatus, R. amabilis, R. corchorifolius, R. lambertianus var. glaber, R. multibracteatus, R. setchuenensis and R. buergeri.

Key words: bramble, Rubus L., chromosome, mixoploid, karyotype