异源三倍体百合减数分裂染色体行为的研究

采用细胞遗传学方法，对Longiflorum×Asiatic系列异源三倍体百合 ‘Bonsoir’（2n=3x=36）小孢子母细胞减数分裂进行了研究和分析。结果显示,有64.31% 的花粉具有活力，且有活力的花粉大小范围在986.33~3 491.68 μm2之间，并呈双峰分布。形成败育花粉的主要原因如下:高度不规则的染色体配对、落后染色体、染色体桥、不均等分离、微核等现象。另外，减数分裂中期Ⅱ纺锤体的异常定向导致了末期Ⅱ二分体和三分体的形成，产生未减数的配子，如融合纺锤体和三极纺锤体；但平行纺锤体和垂直纺锤体不参与未减数配子的形成。一些小孢子母细胞在胞质分裂过程中未形成细胞板，导致单分体的形成以及二分体和三分体的增加，提高了未减数配子的频率。通过对小孢子发生过程中各种现象的观察，对异源三倍体百合在育种中的应用进行讨论。 

Meiotic chromosome behavior in allotriploid cultivar of Lilium hybrids.

The meiosis process and pollen vitality of Longiflorum×Asiatic hybrid ’Bonsoir’ (2n=3x=36) were studied by cytogenetic methods.The results showed that 64.31% pollen grains were viable,and sizes of the viable pollen grains ranged from 986.33 to 3 491.68 μm2,with a bimodal frequency distribution.During meiosis,some phenomena resulted in sterile pollen grains,such as the irregular chromosome associations in meiosis prophase,lagging chromosomes,chromosome bridges,unbalanced segregation,micronucleus,etc.Abnormal orientation of metaphase Ⅱ spindles contributed to production of dyads and triads,which produced unreduced microspores,such as fused spindles and triangle spindles.But parallel and vertical orientation of spindles was not connected with dyad formation.Concerning the cytokinesis,in some pollen mother cells(PMCs),a failure of the reductional wall led to monads,dyads and triads,and finally increased the rate of unreduced pollens.The perspective of this allotriploid in the polyploidy breeding program of Lilium was discussed.