中文摘要：

减数分裂在有性生物的生命周期中起着非常重要的作用,其过程高度保守。减数分裂过程中,染色体配对、联会和重组是遗传变异的源泉、有性生物进化的推动力,也是减数分裂研究的热点之一。在植物减数分裂研究中,还不可能直接观察到染色体在减数分裂过程中的交换情况,往往是通过交换后群体的遗传分析来推测。文章通过图示基因型方法分析了来自花药培养的32个水稻双单倍体（DH）株系,发现少数株系某些染色体部分区段为杂合状态,并利用STS分子标记对杂合状态的真实性进行了验证,推测杂合区段的出现可能与染色体的修复不完全或修复错误有关。研究结果为解释植物减数分裂的机理提供了直接证据。

英文摘要：

Meiosis is a highly conservative process,which plays important role in the life cycles of all sexually reproduc-tive organisms,while the pairing,synapsis,and recombination are the key events in this process and have become the hot-spots in meiosis studies.At present,we cannot observe the process of cross and recombination of chromosomes directly in plant meiosis,and generally conclude the process by analysis the genetic population.In the present study,we analyzed 32 DH lines using graphical genotypes,and found 4 chromosomes out of 32 DH lines had regional heterozygosis,which was further confirmed using STS markers.We suggested that it may cause by repair incompletion or mis-repair of chromsome.These results provid some directly evidence for explaining the mechanism of plant meiosis.