Efficient breeding programs are difficult to implement in honeybees due to their biological specificities (polyandry and haplo-diploidy) and complexity of the traits of interest, with performances being measured at the colony scale and resulting from the joint effects of tens of thousands of workers (called direct effects) and of the queen (called maternal effects). We implemented a Monte Carlo simulation program of a breeding plan designed specifically for Apis mellifera’s populations to assess the impact of polyandry versus monoandry on colony performance, inbreeding level and genetic gain depending on the individual selection strategy considered, i.e. complete mass selection or within-family (maternal lines) selection. We simulated several scenarios with different parameter setups by varying initial genetic variances and correlations between direct and maternal effects, the selection strategy and the polyandry level. Selection was performed on colony phenotypes. All scenarios showed strong increases in direct breeding values of queens after 20 years of selection. Monoandry led to significantly higher direct than maternal genetic gains, especially when a negative correlation between direct and maternal effects was simulated. However, the relative increase in these genetic gains depended also on their initial genetic variability and on the selection strategy. When polyandry was simulated, the results were very similar with either 8 or 16 drones mated to each queen. Across scenarios, polyandrous mating resulted in equivalent or higher gains in performance than monoandrous mating, but with considerably lower inbreeding rates. Mass selection conferred a ~ 20% increase in performance compared to within-family selection, but was also accompanied by a strong increase in inbreeding levels (25 to 50% higher). Our study is the first to compare the long-term effects of polyandrous versus monoandrous mating in honeybee breeding. The latter is an emergent strategy to improve specific traits, such as resistance to varroa, which can be difficult or expensive to phenotype. However, if used during several generations in a closed population, monoandrous mating increases the inbreeding level of queens much more than polyandrous mating, which is a strong limitation of this strategy.

中文翻译：

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考虑一妻多夫、直接和母体对蜂群性能影响的蜜蜂育种计划的模拟研究

由于蜜蜂的生物学特性（一夫多妻和单倍体二倍体）和感兴趣的性状复杂，难以在蜜蜂中实施有效的育种计划，性能是在群体规模上衡量的，并且是由数万名工人的共同作用产生的。称为直接效应）和女王（称为母体效应）。我们实施了专为蜜蜂种群设计的育种计划的蒙特卡罗模拟程序，以根据所考虑的个体选择策略（即完整的大规模选择或家庭内选择）评估一妻多夫与一夫多妻对群体性能、近交水平和遗传增益的影响（母系）选择。我们通过不同的初始遗传方差和直接和母体效应、选择策略和一妻多夫水平之间的相关性，模拟了具有不同参数设置的几种场景。对菌落表型进行选择。所有情景都显示，经过 20 年的选择，蜂王的直接育种值大幅增加。一夫一妻制导致的直接遗传收益明显高于母体遗传收益，尤其是在模拟直接效应和母体效应之间存在负相关时。然而，这些遗传增益的相对增加还取决于它们最初的遗传变异性和选择策略。当模拟一妻多夫时，结果与每只蜂王交配 8 或 16 只雄蜂的结果非常相似。跨场景，与单雄性交配相比，一妻多夫交配在性能方面产生了同等或更高的收益，但近亲繁殖率要低得多。与家庭内选择相比，大规模选择使性能提高了约 20%，但也伴随着近亲繁殖水平的强劲增加（高出 25% 至 50%）。我们的研究是第一个比较蜜蜂育种中一妻多夫与一夫多妻交配的长期影响的研究。后者是改善特定性状的紧急策略，例如对瓦螨的抗性，这可能很难或昂贵的表型。然而，如果在封闭种群的几代中使用，单雄性交配比多雄性交配更能提高皇后的近亲繁殖水平，这是这种策略的一个很大的局限性。与家庭内选择相比，大规模选择使性能提高了约 20%，但也伴随着近亲繁殖水平的强劲增加（高出 25% 至 50%）。我们的研究首次比较了蜜蜂育种中一妻多夫与一夫多妻交配的长期影响。后者是改善特定性状的紧急策略，例如对瓦螨的抗性，这可能很难或昂贵的表型。然而，如果在封闭种群的几代中使用，单雄性交配比多雄性交配更能提高皇后的近亲繁殖水平，这是这种策略的一个很大的局限性。与家庭内选择相比，大规模选择使性能提高了约 20%，但也伴随着近亲繁殖水平的强劲增加（高出 25% 至 50%）。我们的研究是第一个比较蜜蜂育种中一妻多夫与一夫多妻交配的长期影响的研究。后者是改善特定性状的紧急策略，例如对瓦螨的抗性，这可能很难或昂贵的表型。然而，如果在封闭种群的几代中使用，单雄性交配比多雄性交配更能提高皇后的近亲繁殖水平，这是该策略的一个严重限制。我们的研究是第一个比较蜜蜂育种中一妻多夫与一夫多妻交配的长期影响的研究。后者是改善特定性状的紧急策略，例如对瓦螨的抗性，这可能很难或昂贵的表型。然而，如果在封闭种群的几代中使用，单雄性交配比多雄性交配更能提高皇后的近亲繁殖水平，这是这种策略的一个很大的局限性。我们的研究是第一个比较蜜蜂育种中一妻多夫与一夫多妻交配的长期影响的研究。后者是改善特定性状的紧急策略，例如对瓦螨的抗性，这可能很难或昂贵的表型。然而，如果在封闭种群的几代中使用，单雄性交配比多雄性交配更能提高皇后的近亲繁殖水平，这是这种策略的一个很大的局限性。