STUDIES ON KARYOTYPES OF PYRUS IN CHINA(1)

In this paper the karyotypes of 5 pear species in China were analysed. The result indicates that the karyotype of Pyrus phacocarpa, 2n=2x=34=24m+10sm(2SAT), is similar to that of P. betulaefolia, 2n=2x=34=24m+10sm, and thus they belong to the same group of species; the karyotypes of P. sinkiangensis and P. hopeihensis are identical, 2n = 2x = 34 = 16m + 18sm(2SAT), and are similar to that of P. serrulata, making up another group of species. In the two groups of species the former is relatively primitive and the latter seems to be a secondary one, derived from natural hybridization.