Cross- and self-compatibility in various species of the genus Rosa

Summary

Self- and cross-compatibility was evaluated under field conditions in 48 taxa belonging to all sections of subgenus Rosa and subgenus Platyrhodon in the genus Rosa. Four species exhibited fruit set through self-pollination out of the 28 diploid species tested. In contrast, nine out of 12 tetraploid species, all of pentaploid species, and four out of five hexaploid species exhibited fruit set through self-pollination. Thus, it may be generally said that the self-incompatibility in the genus Rosa breaks down with polyploidization. The relationship between self-incompatibility and ploidy level is discussed.