Evidence for reductions in floral attractants with increased selfing rates in two heterandrous species.
Evidence for reductions in floral attractants with increased selfing rates in two heterandrous species.
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DOI：
10.1111/j.1469-8137.2007.02115.x
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发表时间：
2007-08
期刊：
影响因子：
--
通讯作者：
L. Tang;Shuang‐Quan Huang
中科院分区：
文献类型：
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作者：
L. Tang;Shuang‐Quan Huang
虽然理论模型预测低分配到有吸引力的结构，增加动物授粉植物的自交，繁殖成本和效益的经验测量是复杂的。在这里，花的性别分配进行了比较，在两个无蜜源异雄种不同的交配系统：鸭舌草korsakowii（Pontederiaceae），具有中等异交率，鸭舌草，占主导地位的自交。在这两个物种中，镜像花有一个大的深紫色花药和五个小的黄色花药。利用传粉者探访、花粉去除和沉积以及手工授粉后结实的数据，为两组花粉囊之间的功能差异提供了实验证据。蜜蜂授粉的M. korsakowii证明了两组花药的不同功能：黄色（取食）花药的功能是吸引传粉者，但与紫色（授粉）花药的花粉性能相似。此外，在自交种中，取食花药的花粉产量不成比例地减少，这种在异雄种中取食和授粉花药之间的差异分配以前没有被认识到。减少分配到有吸引力的结构，增加自受精率的发现支持性别分配的理论。
Although theoretical models predict low allocation to attractive structures with increased selfing in animal-pollinated plants, empirical measurement of the reproductive costs and benefits is complicated. Here, floral sex allocation was compared in two nectarless heterandrous species with different mating systems: Monochoria korsakowii (Pontederiaceae), which has moderate outcrossing rates, and Monochoria vaginalis, a predominant selfer. In both species, mirror-image flowers have one large dark-purple anther and five small yellow anthers. Experimental evidence is provided for functional differences between the two sets of anthers using data on pollinator visitation, pollen removal and deposition, and seed set after hand pollinations. Flower manipulations in bee-pollinated M. korsakowii demonstrated different functions of the two sets of anthers: the yellow (feeding) anthers function to attract pollinators, but have similar pollen performance to the purple (pollinating) anthers. Furthermore, a disproportional reduction in pollen production of the feeding anthers in the selfing species was found. This differential allocation between feeding and pollinating anthers in heterandrous species has not been recognized before. The finding of reduced allocation to attractive structures with an increase in the rate of self-fertilization supports the theory of sex allocation.