Premise of research. A trade-off between seed mass and seed output defines a central axis of ecological variation among plant species. While an observed negative seed mass–seed output relationship is hypothesized to reflect universal constraints on resource allocation in all plants, domestication has likely altered this relationship.Methodology. I use a data set of seed mass and seed output (measured on a per-plant basis) for 41 of the world’s most widespread crops and 1190 wild plant species to evaluate whether and how domestication has influenced seed mass–seed output relationships in crops. I do so by evaluating (i) whether crops differ systematically from wild plants in terms of their position along a seed mass–seed output axis (assessed using standardized major axis regression models) and (ii) whether crops influence the phylogenetic signals in seed mass and seed output observed among plants (assessed using phylogenetic analyses of Pagel’s λ coupled with randomization tests).Pivotal results. Compared with patterns among wild plants, virtually all crops express higher seed mass for a given seed output. This trend is especially pronounced and statistically significant in crops that have been selected for seed production, though the pattern is also pronounced and statistically significant across nonseed crops. The strength of the phylogenetic signal in seed mass and seed output—which is strong and statistically significant across all plants in the data set—was reduced when crops were included in the analyses.Conclusions. Evolved relationships between seed mass and seed output in plants are influenced by both conscious and unconscious artificial selection, such that artificial selection relaxes strong constraints on trait trade-offs within crops as compared with wild plants. These differences represent a key aspect of how the functional biology of crops differs fundamentally from that of wild plants along “universal” plant trait spectra.

中文翻译：

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作物与种子质量－植物种子产量的权衡

研究前提。种子质量与种子产量之间的权衡决定了植物物种之间生态变异的中心轴。虽然观察到的负种子与种子的产量关系被假定为反映了所有植物对资源分配的普遍限制，但驯化可能改变了这种关系。方法。我使用了41种世界上最普遍的作物和1190种野生植物的种子质量和种子产量的数据集（以单株为基础进行测量），以评估驯化是否以及如何影响作物种子与种子的产量关系。我这样做是通过评估（i）作物在种子质量-种子输出轴上的位置是否与野生植物系统地不同（使用标准化的长轴回归模型进行评估）和（ii）作物是否影响种子质量中的系统发生信号以及在植物之间观察到的种子产量（通过对Pagelλ的系统发育分析和随机测试进行评估）。重要结果。与野生植物中的模式相比，在给定的种子产量下，几乎所有农作物都表现出更高的种子质量。这种趋势在选择种子生产的农作物中尤为明显，在统计上也很显着，尽管这种模式在非种子作物上也很明显并且在统计学上很显着。当将农作物包括在分析中时，系统发生信号在种子质量和种子输出中的强度（在数据集中所有植物中均很强且具有统计意义）会降低。结论。有意和无意的人工选择都影响植物中种子质量和种子产量之间不断发展的关系，因此与野生植物相比，人工选择放宽了作物内性状权衡的严格限制。这些差异代表了作物功能生物学与野生植物在“通用”植物性状谱上的根本不同之处。