种内杂交有杂交优势也存在遗传不兼容现象。对遗传不兼容机理研究，不仅可加深对生殖隔离和物种形成的理解，而且可规避种内杂交的负面因素，充分利用杂种优势。在栽培甘蓝型油菜种内杂交过程中，申请者利用染色体精确辨认技术发现杂交F1植株减数分裂中期I发生同源染色体不配对和减数分裂后期I染色体错分离，导致非整倍体配子形成，结实率显著减少和花粉活性的降低。以及后代出现非整倍体和新的表型性状。本项目将利用现代细胞遗传学和分子生物学技术，通过对减数分裂各时期进行染色体精确识别和观察，寻找引起减数分裂同源染色体不配对和分离异常的原因，了解同源染色体不配对引起遗传不兼容的发生机制。本项目的完成将有助于增进种内杂交遗传不兼容现象的理解。

Intraspecific hybrids exist the phenomena both heterosis and genetic incompatibilities. Understanding the mechanism of genetic incompatibility can not only deepen our comprehension of reproductive isolation and speciation, but also avoid the negative factors of intraspecific crosses, and full utilization heterosis. During the studies of the hybrid process between cultivated Brassica napus, we found that the homologous chromosomes did not pair with high ratio at meiotic metaphase I and chromosomes mis-segregated at meiotic metaphase I in the F1 hybrids, which leaded to the formations of aneuploid gametes. The seed yields and the pollen activities were significantly reduced in F1 hybrids. Most offspring of the hybrids were aneuploidy and showed new phenotypic traits. In this project we will investigate the causes of homologous chromosome un-pairing at meiotic metaphase I, and understand the mechanism of genetic incompatibilities using the techniques of modern cytogenetics and molecular biology. The completion of this project will significantly improve our knowledge about genetic incompatibilities in intraspecific crosses of B. napus.