Abstract:

The effective meiosis period and treating duration of pollen chromosome doubling were researched, based on mastering the meiosis law of microsporocy te of Populus tomentosa ×P. bolleana. The results indicated (1) A certain proportion of the bigger pollen grains could be gotten from the male flower buds induced by cochicine solution, the highest proportion was up to 88% and these bigger pollen grains contained 38 chromosomes by microscopic examination, and could normally germinate by both the common medium and the vivi-fertilization; (2) Generally, so long as the buds were cultured with water for 40 hours, the colour of anther changed from light green to yellowish-green, not to get red, i. e. during the period from the end of bouquet stage to the beginning of diplotene, in which the best doubling effect could be obtained. (3) During the suitable treating duration, there was correlation between the treating frequency and the amount of obtained pollen, considering the 2n pollen ratio and the amount of obtained pollen, the better treating frequency was from 3 to 5 times, the interval between two treatments should be 5 ~ 7 hours.

Key words: Populus tomentosa ×P. bolleana, Pollen chromosome doubling, Meiosis, Effective treating period, Colchicine