Reproductive Effort in Plants. 3. Effect of Reproduction on Vegetative Activity
Reproductive Effort in Plants. 3. Effect of Reproduction on Vegetative Activity
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DOI：
10.1086/284683
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发表时间：
1987-06
期刊：
影响因子：
--
通讯作者：
E. Reekie;F. Bazzaz
中科院分区：
文献类型：
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作者：
E. Reekie;F. Bazzaz
为解释植物间资源分配模式的差异而提出的各种理论的一个基本假设是，不同的结构或活动是可供选择的：一种结构或活动的收益会导致另一种结构或活动的比例损失。我们试图通过确定分配给繁殖的资源是否反映了繁殖对营养生长的影响来在冰草中验证这一假设。这是通过比较在光周期不同的条件下生长的生殖植物和营养植物的生长来完成的。与分配给繁殖的资源相比，该物种的繁殖成本要低得多。尽管在大多数处理中，分配给生殖的资源比例很大，但生殖对总生长几乎没有不利影响；在少数情况下，它实际上促进了营养生长。在分配给生殖的资源与其对营养活动的影响之间的关系上，不同的基因型和环境之间存在很大的差异。这表明，即使在对同一物种的植物进行比较时，繁殖资源的分配也不一定是繁殖成本的可靠指标。此外，由于植物可以经历不同的每单位分配给繁殖的资源的成本，可以想象，植物之间分配给繁殖的资源的差异可能在一定程度上反映了这些成本的差异。例如，繁殖成本低的植物可能能够将更大比例的资源分配给繁殖。这一建议代表了对植物生殖努力差异的传统生活史理论解释的另一种选择。在我们的实验中，不同植物之间繁殖对营养活动的影响的相对差异保持不变，无论这种影响是以生物量损失、碳损失(生物量加呼吸)或氮损失来衡量的。然而，这些衡量繁殖成本的指标与以营养体磷损失衡量的成本之间存在差异，这表明使用适当的货币来评估生殖成本是重要的。
One basic assumption of the various theories proposed to explain differences in resource-allocation patterns among plants is that different structures or activities are alternatives: a gain in one results in a proportional loss in another. We attempted to test this assumption in Agropyron repens by determining whether the resources allocated to reproduction reflect the effect of reproduction on vegetative growth. This was done by comparing the growth of reproductive and vegetative plants grown under conditions differing only in photoperiod. Reproduction in this species was much less costly than the resources allocated to reproduction would indicate. Despite the large proportion of resources allocated to reproduction in most treatments, reproduction had little detrimental effect on total growth; in a few cases, it actually enhanced vegetative growth. There were substantial differences among genotypes and environments in the relationship between the resources allocated to reproduction and its effect on vegetative activity. This suggests that even in comparisons of plants of the same species, resource allocation to reproduction is not necessarily a reliable indicator of the cost of reproduction. Furthermore, since plants can experience different costs per unit of resource allocated to reproduction, it is conceivable that differences among plants in the resources allocated to reproduction may, in part, reflect these differences in cost. A plant with a low cost of reproduction, for example, may be able to allocate a larger proportion of its resources to reproduction. This suggestion represents an alternative to the traditional explanations of life history theory for differences in reproductive effort among plants. In our experiment, the relative differences among different plants in the effect of reproduction on vegetative activity remained the same whether the effect was measured in terms of lost biomass, lost carbon (biomass plus respiration), or lost nitrogen. There were differences, however, between these measures of the cost of reproduction and the cost measured in terms of lost vegetative phosphorus, suggesting that it is important to use the appropriate currency to evaluate the cost of reproduction.