云南松小孢子母细胞减数分裂的研究

以小孢子材料为对象,全程观察并分析了云南松减数分裂各个时期染色体行为及特征.云南松减数分裂构型为11.72II0 0.24II1 0.04I,配对指数为98.67%,环状二价体的频率和配对指数高于其他裸子植物.染色体交叉平均数目(2.42)和染色体异常分裂现象频率(4%)远低于其他裸子植物.云南松在减数分裂过程中染色体的行为表现出高度保守性,与其高度保守的有丝分裂核型较一致.这也说明云南松所在的松属是松科中较原始的类群.

Microsporogenesis and Meiotic Behavior of Pinus yunnanensis Franch

The meiotic behavior of Pinus yunnanensis was investigated using pollen mother cells(PMCs).The average configuration of Pinus yunnanensis was 11.72II0 0.24 II1 0.04I and the pairing index was 98.67%.The number of ring bivalent per PMC and the meiotic index were higher,while the number of chiasma per bivalent and the frequency of irregularities were lower in Pinus yunnanensis than in other gymnosperms studied before.It was shown that the genome of Pinus yunnanensis were highly stable and that there was slight differentiation among homologous chromosomes in Pinus yunnanensis,confirming the previous mitotic analyses.It was also proved that Pinus was more primordial than other taxa in Pinaceae.