Creation of second generation Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) hybrids based on parents from geographically distant locations did not appreciably increase variance in height, frost damage and bud break. New and favorable trait combinations between height and the two adaptive traits were found in the F2 populations. Increased genetic variance and new trait combinations can improve selection efficiency in terms of selection response and increased adaptability. This project tested a novel method for generating higher genetic variance and new trait combinations in Douglas-fir populations. Parents from Southern British Columbia (BC), Washington (WA), Oregon (OR), and Northern BC (NBC) were crossed within each provenance; then selections from BC were crossed with the other sources to create three F1 interpopulation generations. Unrelated random selections from the same F1 population were subsequently crossed to produce three F2 populations. The parental, F1 and F2 generations were concurrently grown in three field tests and were evaluated for height, frost damage, and bud break date. Significant segregation variances were found only in the BCxNBC cross for height in two sites and frost damage in one site and in the BCxOR cross for bud break in one site. In the BCxNBC cross, correlations between breeding values for height and frost damage changed from 0.71 in F1 to − 0.04 in F2 and between height and bud break from − 0.71 to − 0.26. In the BC-OR cross, correlations between height and bud break changed from − 0.71 in F1 to − 0.49 in F2. Our results suggest that creation of wide-cross hybrids may not be very effective in increasing segregation variance in traditional tree improvement programs but in some cases may be considered to increase diversity of trait combinations.

中文翻译：

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沿海花旗松 (Pseudotsuga menziesii (Mirb.) Franco) 宽杂交中 F2 代分离方差和生长、霜害和芽破之间关系的估计

基于来自地理位置遥远的亲本的第二代道格拉斯冷杉 (Pseudotsuga menziesii (Mirb.) Franco) 杂种的创建并没有明显增加高度、霜害和芽断裂的差异。在 F2 种群中发现了身高和两个适应性性状之间新的有利性状组合。增加的遗传变异和新的性状组合可以提高选择反应和适应性方面的选择效率。该项目测试了一种在花旗松种群中产生更高遗传变异和新性状组合的新方法。来自不列颠哥伦比亚省南部 (BC)、华盛顿 (WA)、俄勒冈州 (OR) 和不列颠哥伦比亚省北部 (NBC) 的父母在每个来源内交叉；然后将来自 BC 的选择与其他来源交叉以创建三个 F1 种群间代。来自相同 F1 群体的不相关随机选择随后被交叉以产生三个 F2 群体。亲本、F1 和 F2 代在三个田间试验中同时生长，并评估高度、霜害和萌芽日期。仅在 BCxNBC 杂交中发现了两个地点的高度和一个地点的霜害以及 BCxOR 杂交中一个地点的芽断裂的显着分离差异。在 BCxNBC 杂交中，高度和冻害的育种值之间的相关性从 F1 中的 0.71 变为 F2 中的 − 0.04，高度和芽破之间的相关性从 − 0.71 变为 − 0.26。在 BC-OR 交叉中，高度和芽破之间的相关性从 F1 中的 - 0.71 变为 F2 中的 - 0.49。