用AFLP标记饱和大豆SSR遗传连锁图

Saturating Soybean SSR Based Genetic Linkage Map with AFLP Markers

本研究将52个AFLP标记整合到由宛煜嵩等(2005)构建的含有227个SSR标记的大豆遗传连锁图上,绘制成一张基于SSR-AFLP标记的大豆遗传连锁图,总遗传图距为2512cM,相邻标记间的平均距离为9.0cM。AFLP标记的整合使得图谱的总图距增长了32%。在D1a、E、F、G、K连锁群上,AFLP标记主要整合在连锁群的末端,其中G连锁群尤为明显,末端增加了19个AFLP标记,使得G连锁群的长度由原来的121.2cM增加到259.1cM,相邻标记间的平均距离由原来的7.129cM变为7.197cM;在A2、B1、C2、D2、H、J、L、N、O连锁群,由于加入了AFLP标记使得这些连锁群的标记密度有所增加,改善了标记分布的均匀性。A2连锁群上添加了1个AFLP标记,消除了1个间隙;D2连锁群上添加了2个AFLP标记,提高了原来的一个超过40cM的区间(Satt301和Satt186)标记密度;J连锁群上添加了2个AFLP标记,消除了2个间隙。AFLP标记整合后,大多数连锁群上的SSR标记的顺序和遗传图距几乎与宛煜嵩等(2005)构建的大豆遗传连锁图上的顺序和图距一致,只有M、N和O3个连锁群上的SSR标记顺序发生了一些变化,如M连锁群上的Satt590、Satt201和Satt150及O连锁群上的Satt241和Satt479发生换位;N连锁群上的几个SSR标记的位置发生随机换位。我们认为构建一张理想的遗传图谱,需要来源于不同遗传背?

We integrated 52 AFLP markers to a soybean genetic linkage map comprising of 227 SSR loci that was published by Wan et al.(2005), thus constructed a soybean SSR-AFLP marker based genetic linkage map, spanning 2512cM of Kosambi map distance across 20 linkage groups with the average distance of 9.0cM between adjacent markers. The total length of new SSR-AFLP map is 32% longer than that of the old one, SSR map, due to the integration of AFLP markers. AFLP markers were mainly integrated at the terminals of linkage groups Dla, E, F, G, and K, respectively. Especially in linkage group G, 19 AFLP loci were added to its terminal so that the length of group G increased from 121.2cM to 259.1cM and the average distance between adjacent markers increased from 7.129cM to 7.197cM. Therefore, The joining of AFLP markers increased the density of linkage groups, and improved the uniformity of markers in the linkage groups A2, B1, C1, C2, H, J, L, N, and O. One AFLP marker added in linkage group A2 filled one gap. Two AFLP markers in linkage group D2 filled the big interval which was more than 40cM (Satt301 and Satt186). In addition, two AFLP markers in linkage group J filled two gaps. Most SSR markers in new SSR-AFLP linkage map are accordant to those of SSR linkage map constructed by Wan et al. (2005) except for linkage groups M, N, and O. For instance, Satt590, Satt201, and Satt150 displayed transposition in the linkage group M as well as Satt241 and Satt479 in the linkage group O. Some SSR loci displayed transposition randomly in the linkage group N. We found that constructing a perfect genetic linkage map demands basically different populations with different genetic backgrounds and various types of genetic markers. Although AFLP marker cannot be a complete solution for the problems of big intervals, gaps, and markers' clustering distribution in the linkage groups, it is worth to discuss that AFLP as an ideal molecular marker is useful for constructing the highly density genetic linkage map.