小钻‘白城杨2号’小孢子发生及花粉大小变异  

Microsporogenesis and Variation in Pollen Size of Populus×xiaozhuanica ‘Baicheng-2’

作　　者：戴斐[1] 董黎[1] 王俊豪[1] 宋少宇[1] 尚峰男[1] 王君[1] 

机构地区：[1]北京林业大学林木育种国家工程实验室/林木花卉遗传育种教育部重点实验室/生物科学与技术学院,北京100083

出　　处：《西北植物学报》2013年第5期939-945,共7页Acta Botanica Boreali-Occidentalia Sinica

基　　金：北京林业大学大学生创新创业训练项目(120405);高等学校全国优秀博士学位论文专项资金(201267)

摘　　要：利用醋酸洋红染色压片技术,以温室水培小钻‘白城杨2号’(Populus×xiaozhuanica W.Y.Hsu et Liangcv.‘Baicheng-2’)为材料,对其小孢子发生过程中染色体行为及花粉大小变异进行研究。结果表明:(1)‘白城杨2号’小孢子母细胞减数分裂过程中染色体行为存在一定比例的异常现象,包括终变期单价体、中期Ⅰ染色体提前分离、后期Ⅰ和Ⅱ落后染色体和染色体桥、末期Ⅰ和Ⅱ微核、中期Ⅱ纺锤体定位异常以及胞质分裂异常等,这些异常现象的发生与‘白城杨2号’杂种起源有密切关系。(2)‘白城杨2号’小孢子母细胞减数分裂过程中核仁数目存在动态变化,末期Ⅰ和Ⅱ的子核中最多可看到8个小核仁,可能与杨属树种的多倍体起源有关,其染色体组中可能包含8对具核仁组织者区的染色体。(3)‘白城杨2号’产生空瘪花粉率为3.67%,饱满花粉直径在21.3～52.2μm之间,频率分布总体呈近似高斯分布,0.69%的花粉直径超过37μm,表明其可能产生少量未减数的2n花粉。Chromosome behavior during microsporogenesis and variation of pollen size of Populus X ai- aozhuanica W. Y. Hsu et Liang cv. ＇Baicheng-2＇ in greenhouse were studied by aceto carmine squash tech nique. The results were as follows：（1） Some meiotic abnormalities, such as univalent in diakinesis, preco cious migrated chromosomes in metaphase I ,lagging chromosomes and bridges in anaphase I andⅡ ,mi- cronuclei in telophase Ⅰ and Ⅱ,abnormal orientation of spindles in metaphase Ⅱ and aberrant cytokinesis, were found with certain frequencies,which could be related with the hybrid origin of the ＇Baicheng-2. （2） The nucleolus number changed dynamically from one to eight. In daughter nuclei of some telophase I andⅡ cells,at most 8 small nucleoli were observed,which was probably related with polyploid origin of the ge nus Populus. The genome of the ＇Baieheng-2 may have 8 pairs of chromosomes with nucleolus organizer regions. （3） The ＇Baicheng 2＇ produced 3.67 empty and shrunken pollen grains. The diameter of plump grains ranged from 21.3 to 52.2 μm,and the frequency of pollen diameter followed a similar Gaussian distribution. However,the diameters of 0.69% pollen grains were more than 37μm,suggesting a few of unre duced 2n pollen might be produced.

关 键 词：'白城杨2号’ 小孢子发生 染色体行为 核仁 未减数花粉 

分 类 号：Q944.58[生物学—植物学]