Variation of pollen and meiosis of microsporocyte in an allotriploid white poplar [(Populus to-mentosa × P. Bolleana) × (P. Alba × P. Glandulosa)] were investigated by the squashed technique. Numerous meiotic abnormalities, including precocious migration of chromosomes to the poles, lagging chromosomes, and micronuclei were found, which indicated highly genetic imbalance of this allotriploid. A great number of precocious cytokinesis was found during the second meiotic division. There were dyads and triads in meiotic products,and the diameters of the pollen grains of the allotriploid white poplar ranged from 22. 6 to 62. 6 jum,with a bimodal frequency distribution. That indicated the production of some unreduced pollen grains,which were fertile.%通过醋酸洋红压片等方法观察毛新杨×银腺杨杂种三倍体小孢子母细胞减数分裂及花粉形态,以探讨杂种三倍体雄配子的育性及其细胞学机制.结果显示:(1)在小孢子母细胞减数分裂过程中可观察到部分染色体提前分向两极、落后染色体、微核等一系列染色体异常行为,表明该三倍体存在染色体的高度不平衡性.(2)在减数第二次分裂过程中存在大量胞质分裂提前现象；减数分裂产物中发现有少量二分体、三分体的存在,同时毛新杨×银腺杨杂种三倍体花粉粒的直径变化范围为22.6～62.6 μm,呈现双峰分布,由此推测有一定数量的具可育性的未减数花粉产生.
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