Root tips and stem tips of blackberry tissue culture plantlet were used to observe the chromosomes number of European blackberry 'Thornfree'(Rubus fruticosus var.'Thornfree') by following the wall degradation hypotonic staining method.The main treatment parameters suitable for the observation of the chromosomes number of the blackberry were identified: the pre-disposal treatment time of mixed liquor of 0.02% colchicines and 2 mmol/L 8-hydroxyquino-line(1∶1) 2 h,the enzymolysis time of 2.5% cellulase and 2.5...