| Real root tips of white pitaya (Hylocereus undatus) as material, the chromosome preparation skill was
improved by the wall digestion hypotonic method and the karyotype was analyzed. The results showed that the
optimum chromosome preparation was achieved with root from the germination of seeds on coarse gravels, pretreated
by the mixture of 0.2% colchicine and 0.002 mol/L 8-hydroxyquinoline for 1 h, and dissociated by 1 mol/L HCl for
13 min at 60%. The chromosome number of white pitaya is 2n =2x =22. The 22 chromosomes are all middle
chromosome, so that the karyotype formula of white pitaya is 2n=2x=22=22m, belonging to 1A karyotype. The range
of chromosome relative length is from 6.95%to 12.97%and the karyotype asymmetrical coefficient is 52.67%. |
