【作者】 刘仁虎；

【导师】 孟金陵；

【作者基本信息】 华中农业大学 ， 植物遗传育种， 2004， 博士

【摘要】 本研究采用单向方差分析的方法鉴定了一批对杂种优势有显著贡献的分子标记，在0.01水平上1999年和2000分别检测到126和215个阳性标记，其中93个具有很好的重复性。研究表明该种间F₁杂种优势的产生不仅受杂合位点的影响，受纯合位点的影响也很大，而且杂合位点和纯合位点对杂种优势的贡献都有两面性，即都存在有利或不利的杂合位点和有利或不利的纯合位点。在杂种中，一般有利纯合位点的比例和不利纯合位点的比例差不多，而有利杂合位点的比例往往比不利杂合位点的比例高得多。因此，现有杂种优势的产生多数是由于杂合位点的贡献，而纯合位点的效应尚未得到有效利用。根据这一结果，本研究首次提出将杂种优势在有利杂合位点、不利杂合位点、有利纯合位点和不利纯合位点进行分解的数学模型，显著提高了所解释杂种优势的表现型方差，更合理的揭示了杂种优势复杂的遗传基础的部分内容。而且，研究还表明采用该模型能显著提高杂种优势预测的准确性，为杂种优势的预测和利用提供了新的思路。另外本研究还筛选了30个对杂种优势有“超级”贡献的分子标记，可能对在育种中进行分子标记辅助选择有重要意义。 另外，本研究还在菌核病抗性相关基因的筛选和鉴定方面进行了展开，利用拟南芥cDNA芯片在油菜中筛选了一批与菌核病抗性有关的基因，并采用生物信息学的手段对这些基因的功能和特点进行了分析，推测了其在抵御菌核病入侵的作用机理。 其次，本研究在数据分析过程中还根据需要设计了一批计算机软件，包括遗传连锁图绘制软件、单标记分析软件、分子标记偏分离检测程序、两位点分析软件、AFLP计算机模拟软件等。更多还原

【Abstract】 Laboratory screening with DNA-based markers and field measurements of biomass production were carried out on mach of the 120 trigenomic hybrids, obtained by interspecific hybridization between Brassica napus (AACC) and B. campestris (A’A’). The objective of this study was to elucidate the relationship between molecular markers and biomass heterosis of the interspecific hybrid between B. napus and B. campestris, which has been explored practically in rapeseed production for many years. The experiment was first carried out on sixty-five trigenomic hybrids in 1999. The average over-mid-parent heterosis of biomass production was around 30%, and the highest value was 175.4%. In the following year, the observation was expanded to 120 trigenomic hybrids and the best average over-mid-parent heterosis was 93%. A total of 1477 DNA fragments, generated by Southern hybridization with 50 Brassica cDNA clones and 25 Arabidopsis EST clones, was scored across their parental lines. One hundred twenty-six and 215 fragments were identified as significantly associated with biomass production respectively in the two successive years. Using these active markers, a statistical model to resolve the heterosis is proposed and a new way to make use of the subgenomic heterosis is also discussed.In another experiment, we screened a set of Sclerotinia stem rot resistance related genes in Brassica napus using Arabidopsis cDNA microarray and designed a set of computer software for data analysis.更多还原