Photosynthetic compensation by the reproductive structures in the spring ephemeral Gagea lutea
Photosynthetic compensation by the reproductive structures in the spring ephemeral Gagea lutea
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DOI：
10.1007/s11258-012-0157-7
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发表时间：
2013-02
期刊：
影响因子：
1.7
通讯作者：
Ninuola Sunmonu;Takashi Y. Ida;G. Kudo
中科院分区：
文献类型：
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作者：
Ninuola Sunmonu;Takashi Y. Ida;G. Kudo
从融雪到郁闭，落叶林中短命植物的生长和繁殖在短时间内同步进行。为了阐明降低繁殖成本的机制，研究了春季短命Gagea lutea叶片和非叶片光合产物对种子生产的贡献。叶片生长，叶和非叶光合活性，总同化产物进行了比较生殖完整，花蕾去除，营养植物。利用~（13）CO_2示踪实验定量测定了光合产物向各器官的转运量。鳞茎生长进行了比较手授粉和花蕾去除处理。最后，结实率进行了比较完整，剪叶，剪苞片处理。结果形成的植物保留的叶子比营养和花芽去除植物更长，但延长叶片寿命的同化贡献是可以忽略不计的。苞片光合作用提供的碳足以满足果实发育的需要，而果实光合作用提供的碳被较高的呼吸损失所抵消。叶片光合产物主要转运到鳞茎中，而转运到生殖功能中的作用可以忽略不计。由于花蕾的去除增加了鳞茎的生长，繁殖的缺乏可能导致更多的储存。剪叶对种子产量无影响，而剪苞片显著降低种子产量。因此，叶苞的光合作用可能是果实发育的一个主要碳源。这种生殖结构的自我补偿机制使该物种能够持续进行生殖活动。
Growth and reproduction of spring ephemerals inhabiting deciduous forests progress simultaneously during a short period from snowmelt to canopy closure. To clarify the mechanism to mitigate the cost of reproduction, contributions of foliar and non-foliar photosynthetic products to seed production were examined in a spring ephemeralGagea lutea. Leaf growth, foliar and non-foliar photosynthetic activities, and total assimilated products were compared among reproductive-intact, floral bud-removal, and vegetative plants. Translocation of current photosynthetic products to individual organs was quantified by13CO2-trace experiment. Bulb growth was compared between hand-pollination and floral bud-removal treatments. Finally, seed set was compared between intact, leaf-clipping, and bract-clipping treatments. Fruit-forming plants retained leaves longer than vegetative and floral bud-removal plants, but the assimilative contribution of extended leaf longevity was negligible. Carbon supply by bract photosynthesis was large enough for fruit development, while carbon supply by fruit photosynthesis was offset by the high respiration loss. Foliar photosynthetic products were largely transported to bulbs, while translocation to reproductive functions was negligible. Because the floral bud-removal increased the bulb growth, lack of reproduction could lead to more storage. The leaf-clipping had no effect on seed production, while the bract-clipping significantly reduced the seed production. Therefore, current photosynthesis of leafy bracts might be a major carbon source for fruit development. This self-compensative mechanism of reproductive structure enables the continuous reproductive activity in this species.