Figure 4.
The evolutionary scenario of nine chromosomes of the Rosaceae ancestor. Pear and apple have the same chromosome karyotypes and same chromosomal evolution mode. The Pyreae tribe went through a recent WGD. The Amygdaleae tribe, such as strawberry in the Rosoideae subfamily, has no recent WGD but has chromosome fragmentation and recombination from nine to seven. It is estimated that the ancestor of Rosaceae had nine chromosomes. To demonstrate the evolutionary process from the eudicot ancestor to the Rosaceae ancestor, strawberry was compared with grape.
