Influencing Factors of Tabletting Chromosome of Broussonetiapapyrifeaand Karyotype Analysis

In October of 2017, 5000 seeds were collected from Broussonetiapapyrifea in Guangzhou, Guangdong province, and in February of 2018, germination breaking was carried out.Caryotype analysis was implemented by pellet method.The result showed that the highest mitotic index was obtained from 7-day radicals at 10:00 and 10:30 during March 2 to May 9 of 2018.The morphology of chromosome was clearer when the radicals were treated with ice water for 12 hours.The dispersion of chromosomes was the best when 10 minutes was dissociated.The chromosome numbers of B.papyrifera were 26, diploid, and the karyotype formula was 2 n=2 x=26 m, and the karyotype belonged to 2A type.