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对毛白杨优良无性系进行了染色体检查和花粉观察，结果表明：（１）在毛白杨自然花粉中有形态较大的大花粉粒的存在，大花粉粒染色体计数为１ｎ＝２ｘ＝３８，证明这种大花粉粒为天然染色体未减数的２ｎ花粉；（２）毛白杨分布区中有天然三倍体（２ｎ＝３ｘ＝５７）的存在。现已检出５个毛白杨天然三倍体无性系，它们分别位于毛白杨分布区的北部、西部与南部，相距甚远，表明其存在具有普遍性；（３）毛白杨天然三倍体在材积生长、纤维特性、干型和抗性等方面具有优势，与生产群体相比，其材积生长的遗传增益平均超出５６４％，其中表现最佳的Ｂ３８３可超出１５４％。这些毛白杨天然三倍体的发现，对于杨树遗传育种的学术研究和毛白杨木浆、木片的产业化利用等具有重要意义，显示了毛白杨三倍体的巨大开发潜力和栽培价值。
Chromosome examination and pollen observation were carried out on the excellent clones of Populus tomentosa. The results showed that: (1) There were large pollen grains in the natural pollen of Populus tomentosa. The chromosome number of pollen grains was 1n = 2x = 38, which proved The large pollen grains are 2n pollen which is not deduced from natural chromosomes. (2) The natural triploid (2n = 3x = 57) exists in the distribution area of Populus tomentosa. Five Populus tomentosa natural triploid clones have been detected, which are located in the north, west and south of Populus tomentosa, respectively, far away from each other, indicating that its existence is universal; (3) Populus tomentosa natural triploid in Volume growth, fiber properties, dryness and resistance. The genetic gain of volume growth averaged over 56.4% compared with the production population, of which the best performing B383 was over 154%. The discovery of natural Triploid of Populus tomentosa plays an important role in the academic research of poplar genetic breeding and commercial utilization of poplar wood pulp and wood chips, which shows the tremendous development potential and cultivation value of Triploid Populus tomentosa.