Induction and identification of tetraploids of pear plants (Pyrus bretschneideri and Pyrus betulaefolia)

•Induction of tetraploids of ‘duli’ and ‘Xinli No.7′ with colchicine is feasible.•Tetraploids have desirable traits, such as dwarfism and enlarged leaves.•Both seeds and shoot tips could be used for pear tetraploid induction.•Mixed culture method is an effective way for pear tetraploid induction.