Flowering schedule in a perennial plant; life-history trade-offs, seed predation, and total offspring fitness
Flowering schedule in a perennial plant; life-history trade-offs, seed predation, and total offspring fitness
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DOI：
10.1890/14-1860.1
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发表时间：
2015-08-01
期刊：
影响因子：
4.8
通讯作者：
Dahlgren, Johan P.
中科院分区：
文献类型：
--
作者：
Ehrlen, Johan;Raabova, Jana;Dahlgren, Johan P.
一个季节内繁殖的最佳时间可能受到几个非生物和生物因素的影响。这些因素有时会影响适应度的不同组成部分，使评估网选择困难。我们使用的后代适合度的估计，以研究如何扩散前的种子捕食影响选择开花时间表在一个草本植物的双峰开花模式，猕猴桃。在个人，种子从花上的早期顶生花序有较高的发芽率，并产生较大的幼苗比种子从花上晚基生花序。生殖价值，估计使用人口积分预测模型和占未来性能的大小依赖性差异，是两倍以上的完整的种子从早期的花朵比从晚花的种子。然而，晚花的果实比早花的果实更容易逃脱种子捕食。早花和晚花的繁殖值平衡在63%的捕食强度。在15个自然种群中，分配到晚花的选择强度与平均种子捕食强度呈正相关。我们的研究结果表明，开花时间表的最佳形状，在早花和晚花之间的分配，是由后代数量和质量之间的权衡，以及种群之间的拮抗相互作用的变化影响平衡这种权衡。与此同时，他们还说明，表型选择分析如果不能解释后代适应性的差异，可能会产生误导。
Optimal timing of reproduction within a season may be influenced by several abiotic and biotic factors. These factors sometimes affect different components of fitness, making assessments of net selection difficult. We used estimates of offspring fitness to examine how pre-dispersal seed predation influences selection on flowering schedule in an herb with a bimodal flowering pattern, Actaea spicata. Within individuals, seeds from flowers on early terminal inflorescences had a higher germination rate and produced larger seedlings than seeds from flowers on late basal inflorescences. Reproductive value, estimated using demographic integral projection models and accounting for size-dependent differences in future performance, was two times higher for intact seeds from early flowers than for seeds from late flowers. Fruits from late flowers were, however, much more likely to escape seed predation than fruits from early flowers. Reproductive values of early and late flowers balanced at a predation intensity of 63%. Across 15 natural populations, the strength of selection for allocation to late flowers was positively correlated with mean seed predation intensity. Our results suggest that the optimal shape of the flowering schedule, in terms of the allocation between early and late flowers, is determined by the trade-off between offspring number and quality, and that variation in antagonistic interactions among populations influences the balancing of this trade-off. At the same time they illustrate that phenotypic selection analyses that fail to account for differences in offspring fitness might be misleading.