Assessing costs of reproduction in mountain birch:: The importance of considering the modular level
Assessing costs of reproduction in mountain birch:: The importance of considering the modular level
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DOI：
10.1006/anbo.2000.1206
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发表时间：
2000-09-01
期刊：
影响因子：
4.2
通讯作者：
Ruohomäki, K
中科院分区：
文献类型：
--
作者：
Henriksson, J;Ruohomäki, K
我们研究了雄花序生产对山桦（Betula pubescens subsp.）生长和次年雄花序生产的影响。 czerepanovii 在枝条和枝条水平上。 （枝条在这里被定义为单个生长季节的产物，而枝条是指由多个枝条组成的结构。）与一般的异叶树一样，山桦树冠的扩张是通过长枝条的产生而实现的。我们在柔荑生产当年的枝条水平上发现了长枝生长和雄性繁殖之间的表型权衡。生殖亲本长枝（有雄性柔荑花序的长枝）明显短于营养性长枝（没有雄性柔荑花序的长枝）。相比之下，我们发现雄性繁殖对次年枝条水平的雄性柔荑花序产量没有影响。尽管次生长枝（从亲本长枝侧芽长出的长枝）的平均长度在营养性和生殖性亲本长枝之间没有差异，但个体树的反应存在相当大的个体间差异。此外，雄性柔荑花序的产生会减少山桦的树冠扩张，因为生殖亲本长枝产生的次生长枝数量少于营养亲本长枝的数量。在枝条水平上，总长枝生长与雄性柔荑花序产量之间呈正相关，即没有发现权衡。这可能是因为带有生殖长枝的树枝的强大的库强度（树枝从树的其他地方输入同化物的能力）掩盖了可能的权衡。我们强调在分析模块化生物体的繁殖成本时考虑模块化层次结构的几个级别的重要性。 (C) 2000 年植物学公司年鉴。
We studied the effects of production of male catkins on growth and the subsequent year's male catkin production in mountain birch, Betula pubescens subsp. czerepanovii at both the shoot and branch level. (Shoot is defined here as the product of a single growing season while branch refers to a structure consisting of several shoots.) Like heterophyllous trees in general, mountain birch canopy expansion takes place via the production of long shoots. We found phenotypic trade-offs between long shoot growth and male reproduction at the shoot level in the year of catkin production. Generative parental long shoots (long shoots with male catkins) were significantly shorter than the vegetative ones (long shoots without a male catkin). In contrast, we found no effects of male reproduction on the subsequent year's male catkin production at the shoot level. Although the mean length of secondary long shoots (long shoots growing from the lateral buds of parental long shoots) did not differ between vegetative and generative parental long shoots, there was considerable between-individual variation in the response of individual trees. In addition, production of male catkins diminishes canopy expansion in mountain birch because the number of secondary long shoots produced by generative parental long shoots was smaller than that of vegetative parental long shoots. At the branch level, the association between total long shoot growth and male catkin production was positive, i.e. no trade-off was found. This may be because the strong sink strength (the ability of a branch to import assimilates from elsewhere in the tree) of branches bearing reproductive long shoots masks possible trade-offs. We emphasize the importance of considering several levels of the modular hierarchy when analysing costs of reproduction in modular organisms. (C) 2000 Annals of Botany Company.