用SSR标记提高水稻分子连锁图谱密度

Saturating a Molecular Linkage Map of Rice with SSR Markers

本课题组利用圭 6 30 /台湾粳的DH群体 ,建立了一个水稻RFLP连锁图。该图谱含 175个标记 ,总长 12 2 4 6cM ,相邻标记间平均距离为 7 0cM。但该图标记分布不够均匀 ,存在较多空白区 ,且在第 4和第 8染色体上分别存在一个断点。本研究试图在原有RFLP图谱的基础上 ,添加一些SSR标记 ,以使该图谱标记更加密集和均匀 ,并消除两个断点。共筛选了 36 1对RM引物 ,获得了 183对多态标记 ,在 12条染色体上共整合了 5 7个RM标记 ,染色体连锁图总长度为 1811 2cM ,比原图谱增长了 4 7 9% ,相邻标记间平均距离为 7 8cM ,与原图谱相近。不过 ,两条染色体上的两个断点仍无法消除 。

We had constructed an RFLP marker lingkage map of rice based on a doubled haploid (DH) population derived from a cross between an indica rice variety Gui-630 and a japonica rice variety Taiwanjing. The map contains 175 RFLP markers and covers a total length of 1224 6cM with an average distance of 7 0cM between adjacent markers. But markers on the map are not evenly distributed and there are two breaking points on chromosomes 4 and 8. This study aimed to avoid the two breaking points and make markers distributed denser and more evenly in the map by adding some SSR markers. A total of 361 pairs of SSR primers were used to screen polymorphic markers between the parents. 183 pairs of the primers showed polymorphism and 57 SSR markers were added into the map. The new map covers a total length of 1811 2cM, 47 9% longer than the original map; the average distance between adjacent markers is 7 8cM, similar to the original map. However, the two broken points still exist, implying that the two regions might be less polymorphic and of high recombination frequency.