We showed previously that relations

We showed previously that relationships among the parents can be modeled by including
pedigree information, which results in the GCA variance being properly adjusted to reflect the variance among unrelated samples of the reference population. ASReml internally makes this adjustment by using the numerator relationship matrix to model the additive effects of the parents. However, ASReml does not automatically adjust the SCA variance to account for the possibility that some progenies that appear to be half-sibs based on the immediate generation pedigree may in fact have a closer relationship and share dominance effects. Returning to the pine diallel example, progeny from the cross of parent 590 × 634 are closer than half-sibs to progenies from 626 × 634 (2θ = 0.3125) because parents 590 and 626 are both progenies of ancestor 333. Furthermore, progenies within the cross of 590 × 626 are more closely related than full-sibs, their additive relationship is 2θ = 0.625. ASReml accounts for the increased additive
relationships in these cases when it uses the pedigree information on the parents. It does not,however, account for the small covariance between the dominance effects of families 590 × 624 and 626 × 624 (Δ = 0.0625), or the slightly increased dominance covariance between progenies within the 590 × 626 family (Δ = 0.28125). Ignoring these relationships leads to biased estimates of the dominance variance based on the diallel SCA variance estimate. In the example shown, the bias is expected to be small since the changes in affected coefficients are small.

結果 (中文) 1:

我们以前表明父母之间的关系可以被建模为包括血统信息，结果在被正确的调整，以反映的参考人口之间不相关的样本方差的一般配合力方差。ASReml 内部作此调整通过使用分子关系矩阵来父母的添加剂影响的模型。然而，ASReml 不会自动调整 SCA 方差占一些似乎是半同胞基于立即代系谱可能事实上的后代有更密切的关系和分享显性效应的可能性。回到松双列的例子，从父 590 × 634 十字架的后代比都密切半同胞对后代从 626 × 634 (2t = 0.3125) 因为父母 590 和 626 祖先 333 两个后代。此外，后代内 590 × 626 十字架是比全同胞更密切相关，其添加剂的关系是 2t = 0.625。增加添加剂的的 ASReml 帐户在这些情况下，当它使用的谱系信息上父母的关系。这不，然而，占显性效应的家庭 590 × 624 和 626 × 624 之间的小协方差 (Δ = 0.0625)，或略有增加的优势后代 590 × 626 家庭内部之间的协方差 (Δ = 0.28125)。忽略这些关系导致的显性的变异基于双列 SCA 方差估计的有偏估计。在示例中所示，偏置预计要小，因为在受影响系数变化较小。

結果 (中文) 3:

我们以前的父母之间的关系可以模拟包括系谱信息导致GCA方差作适当调整以反映无关的参考人群样本的方差。ASReml内使这个调整利用分子关系矩阵模型父母的加性效应。然而，ASReml并没有自动调整SCA方差占的可能性，一些看起来是半同胞基于立即代系谱实际上可能后代有更密切的关系和共享的显性效应。回到松双列杂交的例子，从母590×634杂交后代都比半同胞后代从626×634（2θ= 0.3125）因为父母590和626是333代祖先。此外，590×626杂交后代中有更密切的关系比全同胞，他们的关系是2θ= 0.625添加剂。ASReml占增加添加剂在这些情况下的关系，当它使用家谱信息的父母。这不，但是，对于家庭590×624和626×624显性效应之间的协方差小账户（Δ= 0.0625），或略有增加的显性协方差之间的后代在590×626家庭（Δ= 0.28125）。忽略这些关系导致的估计偏差的显性方差基于双列SCA方差估计。在所示的例子中，偏置预计是小的，因为受影响的系数的变化是小的。