遗传 ›› 2005, Vol. 27 ›› Issue (3): 429-434.

• 研究报告 • 上一篇    下一篇

木立芦荟小孢子母细胞减数分裂与花粉育性关系的初步研究

吕 琳1;2;何聪芬2;董银卯2;刘家熙1   

  1. 1.首都师范大学生物系,100037;2.北京工商大学化工学院 北京市植物资源研究开发重点实验室 北京100037
  • 收稿日期:2004-05-19 修回日期:2004-06-21 出版日期:2005-06-10 发布日期:2005-06-10
  • 通讯作者: 何聪芬

Preliminary Studies on the Relationship between Meiosis of Pollen Mother Cells and Pollen Abortion of Aloe arboresens Mill.

LÜ Lin1,2;HE Cong-Fen2;DONG Yin-Mao2;LIU Jia-Xi1   

  1. (1.Department of Biology, Capital Normal University, Beijing 100037,China;2.The college of Chemistry and Environment Engineering, Beijing Technology and Business University,Beijing Key Lab of Plant Resources Research and Development, Beijing,100037,China
  • Received:2004-05-19 Revised:2004-06-21 Online:2005-06-10 Published:2005-06-10
  • Contact: HE Cong-Fen

摘要: 文章从减数分裂过程、小孢子发育两方面,探讨了木立芦荟(Aloe arboresens Mill.)花粉败育的原因。木立芦荟花粉母细胞染色体数目为2n=14,由四对长染色体和三对短染色体组成,属二型性核型。其减数分裂异常,发现存在单价体和多价体、染色体桥、落后染色体、不均等分离、微核等。同时观察到木立芦荟染色体具有极度的粘质性,使减数分裂各阶段的染色体不易散开。统计各种异常现象出现的频率并分析了这些异常现象形成的可能机制及对正常小孢子形成的影响,推测染色体间的丝状粘连可能是木立芦荟小孢子母细胞减数分裂异常并导致败育花粉产生的主要因素。成熟花粉粒中90%以上为败育花粉,属碘败型。

关键词: 减数分裂, 花粉败育, 小孢子母细胞, 木立芦荟

Abstract: The main reason for pollen abortion in Aloe arboresens Mill. was studied through the observation of meiosis and the microspore development of its pollen mother cells(PMCs). There are 14 chromosomes in the PMC of Aloe arboresens Mill., containing four pairs of long chromosomes and three pairs of short ones, and this karyotype belongs to dichotocarpism. Abnormalities observed were fallen into four categories:(1) Univalents, they were caused by failure in pairing, asynapsis and precocious cancellation of terminal chiasma. Oriented univalent pair was distributed at two poles normally in anaphase, while non-oriented univalent pair only at one pole. Another factor leading to univalents was that chromosomes were paired but without substantial exchange. (2) Multivalents. They might be produced by translocation heterozygote.(3) Chromosome bridges. There were three kinds of bridges in anaphaseⅠand anaphaseⅡ: single and double chromosome bridge as well as “diagonal bridge”.(4) A few cells were found with lagged chromosomes, micronuclei and unbalanced segregation of the chromosomes. In the later stages of meiosis, well-spread chromosomal configurations were rare because of the extremely sticky nature of the chromosome. The number and ratio of abnormalities were analysed and the relationship between abnormalities and pollen sterility were discussed. It is concluded that the sticky nature of the chromosome is the main reason for abnormal meiosis of Aloe arboresens Mill.PMC and pollen sterility. More than 90% of matured pollen grains were sterile.

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