龙须草核型分析和花粉母细胞减数分裂的细胞学研究  

Karyotype Analysis and Pollen Mother Cells Meiosis Observation in Eulaliopsis binata

作　　者：刘传虎[1] 张秋平[1] 姚家玲[1] 陈春丽[1] 

机构地区：[1]华中农业大学生命科学技术学院,武汉430070

出　　处：《中国农业科学》2007年第1期27-33,共7页Scientia Agricultura Sinica

基　　金：国家自然科学基金项目(39980016)

摘　　要：【目的】研究和确定禾本科无融合生殖植物——龙须草(Eulaliopsisbinata)的染色体数目并进一步判断其倍性。【方法】采用根尖压片法确定龙须草的染色体数目,通过分析龙须草核型和花粉母细胞减数分裂过程中染色体行为确定其倍性水平。【结果】龙须草根尖细胞染色体数目为40条,核型公式为2n=40=18m+2sm,属于1B型。龙须草花粉母细胞减数分裂为连续型胞质分裂,终变期染色体构型为20Ⅱ。在其减数分裂过程观察到中期Ⅰ出现不配对染色体(34.3%),后期Ⅰ出现落后染色体,变幅为1～3个(32.4%),末期Ⅱ～四分体时期可观察到明显的微核(20%)等异常现象。【结论】龙须草是异源四倍体植物,具有40条染色体。[Objective] The study was conducted to confirm the chromosome number in Eulaliopsis binata, which is an apomictic Graminae plant, and to further identify its ploidity. [Method] The number of chromosomes in E, binata was calculated by a root tip squashing method. The ploidity was analyzed by karyotyping and chromosome behavior observation during the meiosis process of pollen mother cells. [ Result ] Results showed that the number of chromosomes in E. binata was 40. Its Karyotype was formulated as 2n=40=18m＋2sm, which indicates a Stebbins＇s 1B type. The meiosis in E, binata undergoes successive cytokinesis. There are 20 bivalents appearing at the stage of diakinesis. Further study observed some abnormal events including unpaired chromosomes （34.3%） at metaphase Ⅰ, one or three lagging chromosomes （32.4%） at anaphase I and also some micronuclei during the tetrad period. [ Conclusions] The results identified E. binata a heterotetraploid plant with 40 chromosomes.

关 键 词：龙须草 染色体 核型 减数分裂 异源四倍体 

分 类 号：S157.433[农业科学—土壤学] S561[农业科学—农业基础科学]