Efficiencies of F2 and backcross generations for bulked segregant analysis using dominant markers
Efficiencies of F2 and backcross generations for bulked segregant analysis using dominant markers
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DOI：
10.2135/cropsci2000.403626x
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发表时间：
2000-05-01
期刊：
影响因子：
2.3
通讯作者：
Caligari, PDS
中科院分区：
文献类型：
--
作者：
Mackay, IJ;Caligari, PDS
批量分离分析(BSA)越来越多地被用作数量性状座位(QTL)的筛查，已被认为在回交(BC)群体中比在F-2群体中更容易检测到。然而，对于显性标记，在F-2中分离的座位数量将是BC的两倍，并且F-2和BC的假阳性结果的概率不同。这项研究是通过对所选群体的基因组成的理论估计来重新检验BC和F-2群体用于BSA的相对价值。结果表明，将分离在F-2中的标记座位数增加一倍，QTL到最近标记的预期距离大约减半，而F-2的体积大小可以减少到BC的近一半，但仍有相同的假阳性概率。结果表明，在相同的重组频率下，BC检测QTL的能力略优于F-2。然而，如果考虑到最接近的标记到QTL的可能距离，F-2是更有利的世代。总体而言，对于优势标记系统来说，F-2是进行BSA的最佳世代。
Bulked segregant analysts (BSA) is being used increasingly as a screen for quantitative trait loci (QTL), which have been suggested to be more easily detected in backcross (Bc) populations than in the F-2. However, for dominant markers the number of loci segregating in the F-2 will be double that in the Bc, and the probability of false-positive results differs between F-2 and Bc generations. This study was conducted to re-examine the relative value of Bc and F-2 populations for use in BSA by using theoretical estimates of the genotypic composition of the selected bulks. It is shown that doubling the number of marker loci segregating in the F-2 roughly halves the expected distance from the QTL to the nearest marker, while the bulk size in the F-2 can be reduced to nearly one-half that of the Bc and still give the same probability of a false positive. The results show that for the same recombination frequency, the Bc is slightly superior to the F-2 in its ability to detect QTL. However, if the likely distance of the nearest marker to the QTL is taken into account, the F-2 is the more favorable generation. Overall, for dominant marker systems, the F-2 is therefore the best generation in which to conduct BSA.