Bajcz Alex W, Drummond Francis A
School of Biology and Ecology University of Maine at Orono Orono ME USA.
Ecol Evol. 2017 Jun 15;7(15):5645-5659. doi: 10.1002/ece3.3109. eCollection 2017 Aug.
Plant reproductive trade-offs are thought to be caused by resource limitations or other constraints, but more empirical support for these hypotheses would be welcome. Additionally, quantitative characterization of these trade-offs, as well as consideration of whether they are linear, could yield additional insights. We expanded our flower removal research on lowbush blueberry () to explore the nature of and causes of its reproductive trade-offs. We used fertilization, defoliation, positionally biased flower removal, and multiple flower removal levels to discern why reproductive trade-offs occur in this taxon and to plot these trade-offs along two continuous axes. We found evidence through defoliation that vegetative mass per stem may trade off with reproductive effort in lowbush blueberry because the two traits compete for limited carbon. Also, several traits including ripe fruit production per reproductive node and fruit titratable acidity may be "sink-limited"-they decline with increasing reproductive effort because average reproductive structure quality declines. We found no evidence that reproductive trade-offs were caused by nitrogen limitation. Use of reproductive nodes remaining per stem as a measure of reproductive effort indicated steeper trade-offs than use of the proportion of nodes remaining. For five of six traits, we found evidence that the trade-off could be concave down or up instead of strictly linear. . To date, studies have aimed primarily at identifying plant reproductive trade-offs. However, understanding how and why these trade-offs occur represent the exciting and necessary next steps for this line of inquiry.
植物繁殖权衡被认为是由资源限制或其他约束因素引起的，但这些假设若能得到更多实证支持将是很受欢迎的。此外，对这些权衡进行定量表征，以及考虑它们是否呈线性，可能会带来更多见解。我们扩展了对矮丛蓝莓（）的去花研究，以探索其繁殖权衡的本质和原因。我们使用施肥、去叶、位置偏向去花以及多个去花水平，来探究该分类群中繁殖权衡为何会发生，并沿着两个连续轴描绘这些权衡。我们通过去叶发现，矮丛蓝莓中每根茎的营养物质可能会与繁殖投入进行权衡，因为这两个性状会争夺有限的碳。此外，包括每个繁殖节点的成熟果实产量和果实可滴定酸度在内的几个性状可能是“库限制的”——它们会随着繁殖投入的增加而下降，因为平均繁殖结构质量会下降。我们没有发现繁殖权衡是由氮限制引起的证据。使用每根茎上剩余的繁殖节点数量作为繁殖投入的衡量指标，表明权衡比使用剩余节点比例更为明显。对于六个性状中的五个，我们发现有证据表明权衡可能是向下凹或向上凹，而不是严格呈线性。。迄今为止，研究主要旨在识别植物的繁殖权衡。然而，理解这些权衡如何以及为何发生是这一研究方向令人兴奋且必要的下一步。
