毛白杨异源三倍体形态和减数分裂观察

毛新杨×毛白杨［（Ｐｏｐｕｌｕｓｔｏｍｅｎｔｏｓａ×Ｐ．ｂｏｌｅａｎａ）×Ｐ．ｔｏｍｅｎｔｏｓａ］异源三倍体无性系综合形态特征为偏毛白杨，部分近于新疆杨（如长枝叶），只有长枝叶、雄花序等表现出了较明显的巨大性．其花粉母细胞减数分裂进程较毛白杨、毛新杨约快８～１２ｈ，且极不同步．三倍体染色体联会和分离的行为复杂，在中期Ⅰ除了出现三价体、二价体、单价体外，还可见到四价体和五价体；在后期Ⅰ、后期Ⅱ亦可见到较高频率的落后染色体，遗传上属于部分异源三倍体．这些毛白杨异源三倍体表现高度不育，但存在着无性系差异．花粉部分可育三倍体（Ｂ３０２）的存在，为相关的遗传分析及倍性育种实践提供了极其有用的材料

Morphology and Meiosis of Chinese White Poplar

This paper reported morphology and meiosis in the allotriploids of Chinese White Poplar( Populus tomentosa × P. bolleana )× P. tomentosa ]. All the hybrid's triploids showed giantism in leaf of long shoot and male catkin, and comprehensive morphological alike to their female parents, partial traits (for instance leaf of long shoot etc.) alike to P. bolleana.The meiosis duration of pollen mother cell(PMC) in allotriploids were 8～12h faster than P. tomentosa and P. bollena , and very non synchronism.It is also observed that the trivalents,bivalents,univalent and guadrivalents, pentavalents in MetaphaseⅠ,and the lagging chromosomes in AnaphaseⅠ andⅡ.By chromosomal synapses in meiosis of PMC of allotriploids and their parents, it is proved that this triploids is the segmental alloplyloid. The triploids showed hightest sterile, but only clone B302 produced little fertility pollen.