Department of Crop Sciences, Georg-August-University Göttingen, Von-Siebold-Str. 8, 37075, Göttingen, Germany.
Theor Appl Genet. 2010 Mar;120(5):921-31. doi: 10.1007/s00122-009-1221-0. Epub 2009 Dec 2.
Linkage disequilibrium was investigated in canola quality winter rapeseed to analyze (1) the prospects for whole-genome association analyses and (2) the impact of the recent breeding history of rapeseed on linkage disequilibrium. A total of 845 mapped AFLP markers with allele frequencies >or=0.1 were used for the analysis of linkage disequilibrium in a population of 85 canola quality winter rapeseed genotypes. A low overall level of linkage disequilibrium was found with a mean r (2) of only 0.027 over all 356,590 possible marker pairs. At a significance threshold of P = 2.8 x 10(-7), which was derived by a Bonferroni correction from a global alpha-level of 0.1, only 0.78% of the marker pairs were in significant linkage disequilibrium. Among physically linked marker pairs, the level of linkage disequilibrium was about five times higher with more than 10% of marker pairs in significant linkage disequilibrium. Linkage disequilibrium decayed rapidly with distance between linked markers with high levels of linkage disequilibrium extending only for about 2 cM. Owing to the rapid decay of linkage disequilibrium with distance association analyses in canola quality rapeseed will have a significantly higher resolution than QTL analyses in segregating populations by interval mapping, but much larger number of markers will be necessary to cover the whole genome. A major impact of the recent breeding history of rapeseed on linkage disequilibrium could not be observed.
对油菜冬季优质品种进行连锁不平衡分析，以研究（1）全基因组关联分析的前景，（2）油菜近期选育历史对连锁不平衡的影响。利用一个由 85 个油菜冬季优质品种组成的群体，对 845 个具有等位基因频率大于等于 0.1 的 AFLP 图谱标记进行连锁不平衡分析。结果发现，连锁不平衡程度总体较低，356590 个可能的标记对中平均 r2 仅为 0.027。在通过 Bonferroni 校正得到的全局显著水平α为 0.1 时，达到 P = 2.8 x 10(-7)的显著水平的标记对仅占 0.78%。在物理连锁的标记对中，连锁不平衡水平约高 5 倍，超过 10%的标记对达到显著连锁不平衡。连锁不平衡随连锁标记之间的距离迅速衰减，高度连锁不平衡的标记对之间的连锁距离约为 2cM。由于连锁不平衡随距离迅速衰减，因此与区间作图的 QTL 分析相比，油菜优质品种的关联分析的分辨率将显著提高，但为了覆盖整个基因组，需要更多的标记。油菜近期选育历史对连锁不平衡的影响并不显著。
