BACKGROUND AND AIMS Understanding how plant allometry, plant architecture, and phenology contribute to fruit production can identify those plant traits that maximize fruit yield. In this study, we compared these variables and fruit yield for two shrub species, Vaccinium angustifolium and Vaccinium myrtilloides to test the hypothesis that phenology is linked to the plants' allometric traits, which are predictors of fruit production. METHODS We measured leaf and flower phenology and the aboveground biomass of both Vaccinium sp. in a commercial wild lowbush blueberry field (Quebec, Canada) over a two-year crop cycle; one year of pruning followed by one year of harvest. Leaf and flower phenology were measured, and the allometric traits of shoots and buds were monitored over the crop cycle. We hand-collected the fruits of each plant to determine fruit attributes and biomass. KEY RESULTS During the harvesting year, the leafing and flowering of V. angustifolium occurred earlier than that of V. myrtilloides. This difference was related to the allometric characteristics of the buds due to differences in carbon partitioning by the plants during the pruning year. Through structural equation modeling, we identified that the earlier leafing in V. angustifolium was related to a lower leaf bud number, while earlier flowering was linked to a lower number of flowers per bud. Despite differences in reproductive allometric traits, the vegetative biomass still determined the reproductive biomass in a log-log scale model. CONCLUSIONS Growing buds are competing sinks for nonstructural carbohydrates. Their differences in both number and characteristics, e.g., number of flowers per bud, influence levels of fruit production and explain some of the phenological differences observed between the two Vaccinium species. For similar aboveground biomass, both Vaccinium species had similar reproductive outputs in terms of fruit biomass, despite differences in reproductive traits such as fruit size and number.

中文翻译：

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植物异速生长如何影响两种牛痘属植物的芽物候和果实产量

背景和目标了解植物异速生长、植物结构和物候学如何促进水果生产可以识别那些使水果产量最大化的植物性状。在这项研究中，我们比较了两种灌木物种的这些变量和果实产量，Vaccinium angustifolium 和 Vaccinium myrtilloides，以检验物候与植物异速生长性状相关的假设，这些异速生长性状是果实产量的预测因子。方法我们测量了两种牛痘的叶和花物候以及地上生物量。在两年作物周期内的商业野生低灌木蓝莓田（加拿大魁北克）中；一年的修剪，然后是一年的收获。测量了叶和花的物候，并在整个作物周期监测芽和芽的异速生长性状。我们手工收集了每种植物的果实，以确定果实的属性和生物量。主要结果 在收获年中，狭叶柳的生叶和开花早于桃金娘。这种差异与芽的异速生长特性有关，原因是修剪年份植物对碳分配的差异。通过结构方程模型，我们发现 V. angustifolium 较早的叶子与较低的叶芽数有关，而较早的开花与较低的每个芽的花数有关。尽管生殖异速生长性状存在差异，但植物生物量仍然在对数对数比例模型中决定了生殖生物量。结论 正在生长的芽是非结构性碳水化合物的竞争汇。它们在数量和特征上的差异，例如每个芽的花数，影响果实产量水平，并解释了在两个越桔物种之间观察到的一些物候差异。对于相似的地上生物量，尽管果实大小和数量等繁殖性状存在差异，但两种牛痘物种在果实生物量方面具有相似的繁殖产出。