Specialized pollination by honeybees in Cymbidium dayanum, a fall-winter flowering orchid
Specialized pollination by honeybees in Cymbidium dayanum, a fall-winter flowering orchid
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DOI：
10.1111/1442-1984.12231
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发表时间：
2019-01-01
影响因子：
1.4
通讯作者：
Sugiura, Naoto
中科院分区：
文献类型：
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作者：
Matsuda, Yoshiyuki;Sugiura, Naoto
对日本九州南部濒危附生兰花Cymbidium dayanum的花生物学和传粉机制进行了研究。花期从秋季到冬季约为4个月，每株植株上的花序通常不同步开花，单花通常持续一个月。无花蜜的花是自交的，但不能自主自花授粉；兰花需要通过欺骗来吸引传粉者来生产蒴果。野外观察表明，尽管花期较长，但这些花完全由日本蜜蜂（Apis cerana japonica）授粉。工蜂为花授粉和/或在胸上接受传粉，同时从唇腔中逃脱。在种群水平上的自然结实率（授粉成功的估计）在年际变化，但通常较低，这是由于冬季气候寒冷和缺乏花蜜奖励，蜜蜂工蜂很少访花的结果。因为大多数在冬季人工授粉的花都成功地变成了蒴果，所以寒冷并不是坐果率低的直接原因。我们的研究结果明确表明，即使在冬季中期，温带植物物种也可以获得蜜蜂授粉生态位。我们推测了冬花紫苏的优势。
Floral biology and pollination mechanisms of Cymbidium dayanum, an endangered epiphytic orchid, were investigated in south Kyushu, Japan. The flowering period spanned approximately 4 months from fall to winter, with the inflorescences often blooming asynchronously on each plant and individual flowers commonly lasting for a month. The nectarless flowers are self-compatible but cannot autonomously self-pollinate; the orchid needs to attract pollinators by deceit for capsule production. The field observations showed that the flowers were pollinated exclusively by the Japanese honeybee Apis cerana japonica, despite its long flowering period. The worker bees pollinated flowers and/or received the pollinarium on the thorax, while escaping from the labellum chamber. The natural fruit-set ratios at the population level, an estimate of pollination success, varied interannually but were generally low, as the result of infrequent flower visits by honeybee workers owing to the cold winter climate and the lack of a nectar reward. Because most flowers that were artificially pollinated in the winter successfully developed into capsules, the coldness was not considered a direct cause of the low fruit-set ratios. Our results explicitly indicate that the bee pollination niche could be available to temperate plant species even during mid-winter. We inferred advantages for the winter flowering of C. dayanum.