Houle Gilles
Département de Biologie, Université Laval, Sainte-Foy, Québec, Canada G1K 7P4.
New Phytol. 2002 Jun;154(3):689-694. doi: 10.1046/j.1469-8137.2002.00418.x.
• Internal conflicts in the allocation of resources lead to trade-offs or compromises that can influence fitness and the evolution of specific life-history traits. • Here, the reproductive schedule of Floerkea proserpinacoides plants, a spring ephemeral annual of the deciduous forests of eastern North America, was manipulated to determine the presence of potential conflicts between growth and reproduction, and the advantage of early reproduction. • Plants on which flowering was delayed had a greater relative growth rate (RGR) and vegetative biomass than control plants after 8 wks (when control plants started to senesce). Delayed-flowering plants took 1 week longer to senesce, which allowed them to mature almost as many seeds as did control plants in 8 wks. • However, late flowering in F. proserpinacoides may be maladaptive. With reduced light availability through canopy closure, early flowering plants can rapidly divert most of the resources accumulated in the stem and leaves to seed maturation. Thus, the advantage of maintaining a higher RGR by delaying flowering is associated with the greater disadvantage of necessitating more time to mature seeds.
• 资源分配中的内部冲突会导致权衡或妥协,进而影响适合度和特定生活史特征的进化。• 北美东部落叶林的一种春季短命一年生植物——弗罗尔凯草(Floerkea proserpinacoides)的繁殖时间表被人为操控,以确定生长与繁殖之间潜在冲突的存在,以及早期繁殖的优势。• 开花被延迟的植株在8周后(此时对照植株开始衰老)比对照植株具有更高的相对生长速率(RGR)和营养生物量。延迟开花的植株衰老时间延长了1周,这使得它们在8周内成熟的种子数量几乎与对照植株一样多。• 然而,弗罗尔凯草延迟开花可能是不利的。随着树冠郁闭导致光照可用性降低,早期开花的植株能够迅速将茎和叶中积累的大部分资源转移到种子成熟上。因此,通过延迟开花维持较高RGR的优势与需要更多时间使种子成熟的更大劣势相关联。