How do sink and source activities influence the reproduction and vegetative growth of spring ephemeral herbs under different light conditions?
How do sink and source activities influence the reproduction and vegetative growth of spring ephemeral herbs under different light conditions?
复制标题
不同光照条件下，库源活动如何影响春季短命草本植物的繁殖和营养生长？
DOI：
10.1007/s10265-014-0640-4
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发表时间：
2014
影响因子：
2.8
通讯作者：
Kudo G
中科院分区：
文献类型：
--
作者：
Sunmonu N;Kudo G
栖息在落叶林中的春季短命草本植物通常在初夏树冠关闭之前完成繁殖和营养生长。然而，树冠早期关闭带来的遮荫对繁殖产出和营养生长的影响可能会有所不同，具体取决于每个物种当前繁殖和未来生长储存之间光合产物的季节性分配模式。为了阐明库-源平衡对春季短命草本植物黄花种子生产和球茎生长的影响，我们在树冠和开放条件下进行了苞片去除处理（源减少）和花芽去除处理（库减少）。森林和空地以及处理之间的叶子固碳没有差异。不同地点之间的苞片碳固定也相似，但当花芽被移除时，碳固定趋于减少。开放条件下的种子产量较高，但两种光照条件下的苞片去除处理均导致种子产量下降。相反，球茎生长与光照条件和去苞处理无关，但通过去芽处理大大增加。因此，叶子和苞片分别作为营养和生殖功能的专门来源器官，但当植物未能结果时，苞片的光合产物被灵活地用于鳞茎生长。明亮期的延长有利于该物种的种子生产（即源有限），但不利于营养生长（即库有限）。
Spring ephemeral herbs inhabiting deciduous forests commonly complete reproduction and vegetative growth before canopy closure in early summer. Effects of shading by early canopy closure on reproductive output and vegetative growth, however, may vary depending on the seasonal allocation patterns of photosynthetic products between current reproduction and storage for future growth in each species. To clarify the effects of sink–source balance on seed production and bulb growth in a spring ephemeral herb,Gagea lutea, we performed a bract removal treatment (source reduction) and a floral-bud removal treatment (sink reduction) under canopy and open conditions. Leaf carbon fixations did not differ between the forest and open sites and among treatments. Bract carbon fixations were also similar between sites but tended to decrease when floral buds were removed. Seed production was higher under open condition but decreased by the bract-removal treatment under both light conditions. In contrast, bulb growth was independent of light conditions and the bract-removal treatment but increased greatly by the bud-removal treatment. Therefore, leaves and bracts acted as specialized source organs for vegetative and reproductive functions, respectively, but photosynthetic products by bracts were flexibly used for bulb growth when plants failed to set fruits. Extension of bright period was advantageous for seed production (i.e., source limited) but not for vegetative growth (i.e., sink limited) in this species.