A highly recombined, high-density, eight-founder wheat MAGIC map reveals extensive segregation distortion and genomic locations of introgression segments.
A highly recombined, high-density, eight-founder wheat MAGIC map reveals extensive segregation distortion and genomic locations of introgression segments.
复制标题
DOI：
10.1111/pbi.12504
复制
发表时间：
2016-06
影响因子：
13.8
通讯作者：
Mackay IJ
中科院分区：
文献类型：
--
作者：
Gardner KA;Wittern LM;Mackay IJ
多亲代高级杂交 (MAGIC) 群体作图为作物物种的标记和 QTL 作图提供了独特的机遇和挑战。我们构建了第一个小麦八亲本 MAGIC 遗传图谱，包含 18,601 个 SNP 标记。我们根据小麦基因组序列验证了我们的图谱的准确性，并发现与已发布的遗传图谱相比，准确性有所提高。我们的地图显示，由于创建种群所需的三代杂交，精度显着提高。这在染色体的着丝粒周围区域最为明显。 16% 的映射标记表现出分离扭曲 (SD)，其中许多发生在长 (>20 cM) 块中。一些最长和最扭曲的块与基因组的非着丝粒高标记密度区域共线，表明它们是从其他草种引入面包小麦基因库的基因渗入片段的候选者。我们详细研究了其中两个连锁块，并发现强有力的证据表明，4AL 染色体上的一个（显示针对创始人 Robigus 的 SD）是种间基因渗入片段。完整的地图可从 http://www.niab.com/pages/id/326/Resources 获取。
Multiparent Advanced Generation Intercross (MAGIC) mapping populations offer unique opportunities and challenges for marker and QTL mapping in crop species. We have constructed the first eight‐parent MAGIC genetic map for wheat, comprising 18 601 SNP markers. We validated the accuracy of our map against the wheat genome sequence and found an improvement in accuracy compared to published genetic maps. Our map shows a notable increase in precision resulting from the three generations of intercrossing required to create the population. This is most pronounced in the pericentromeric regions of the chromosomes. Sixteen percent of mapped markers exhibited segregation distortion (SD) with many occurring in long (>20 cM) blocks. Some of the longest and most distorted blocks were collinear with noncentromeric high‐marker‐density regions of the genome, suggesting they were candidates for introgression fragments introduced into the bread wheat gene pool from other grass species. We investigated two of these linkage blocks in detail and found strong evidence that one on chromosome 4AL, showing SD against the founder Robigus, is an interspecific introgression fragment. The completed map is available from http://www.niab.com/pages/id/326/Resources.