菊属植物多倍体基因组的产生及其进化动态

本项目拟运用分子标记和染色体原位杂交技术对菊属植物中主要多倍体类群的基因组结构和染色体组组成进行研究，揭示不同倍性植株的遗传学特点，分析多倍化前后有关遗传物质的动态变化规律，结合现有的形态和细胞地理学资料，推测该属植物主要多倍体类型的产生过程和机制，了解多倍体基因组的进化动态及其物种形成的关系。

Polyploid is widely acknowledged as a major mechanism of adaptation and speciation in plants. Recent estimates suggest that 70% of all angiosperm have experienced one or more episodes of polyploidization. However, it remains unclear how polyploidy facilitates evolution and adaptation. In this study, the 2n and 4n genomes of Dendranthema indicum were compared using RAPD and ISSR methods. The ITS sequences of rDNA gene and three non-coding regions of chloroplast DNA for each sample were cloned and sequenced. The results showed the existence of obviously genetic differences between 2n and 4n genomes, and between the different populations of tetraploid as well, suggesting that the tetraploid of D. indicum might have formed recurrently from different populations of their progenitors, and and the two diploids (D. indicum var. nankingense and D. indicum var. aromaticum) are not the direct ancestors of the tetraploid.