Study on Pollen Chromosome Doubling in Zenjimaru Persimmon

<正> The factors influencing pollen chromosome doubling in Zenjimaru persimmon were studied, based on the knowledge of meiosis process of pollen mother cells. The results showed: (1) the suitable concentration of colchicine was 0.3-0. 5%; (2) the best doubling effect could be obtained during the period from the diplotene stage to the diakinasis stage, and the highest proportion was up to 40.6%; (3) considering giant pollen ratio and proportion of staminate-flower collection, the better treating frequency was 3 times; (4) giant pollen, which formed mainly from dyad and had bigger cell nucleus volume, was unreduced and hexaploid.