Pellegrino Giuseppe, Bellusci Francesca, Palermo Anna Maria
Department of Biology, Ecology and Earth Sciences University of Calabria Rende CS Italy.
Ecol Evol. 2017 Aug 2;7(18):7171-7177. doi: 10.1002/ece3.3264. eCollection 2017 Sep.
Floral displays, influencing attractiveness to insects, increase the number of pollinator visits and the efficiency of each visit in terms of pollen exchange and thus affect the plant reproductive success. Here, we conducted an in situ manipulation experiment to investigate whether the floral modifications affect reproductive success in natural orchid populations of and . We estimated male and female reproductive success of three treatment groups, disassembly of floral tube, cutting of lip, and painting of the callus surface, in terms of pollinaria removed/deposited and fruit production. Results revealed that phenotypic modification had opposite effects on reproductive success of two examine species. Indeed, reproductive success was significantly increased by the detached of the petals and sepals, and decreased, due to callus painting and lip removal, in . On the contrary, unmanipulated plants of showed significantly higher value of pollinaria removed and deposited and fruit set than manipulated ones. The differences between and agree to the different pollination strategy of examined species. shows shelter imitation strategy, and thus, the disassembly of tunnel-like corolla does not allow the insects to use the flower as a refuge, while is a sexually deceptive orchid and therefore the opening of the flower made more visible callus (visible at a greater distance) increasing the pollinators attraction. This study provides evidence that pollinators were largely sensitive to the experimental modification of the flower phenotype, which is consistent with the presence of significant selection on individual floral characters. Our experimental investigations of the effects of variation in display on pollinator visitation provide insights into the evolution of floral morphology in orchid with shelter imitation strategy.
花的展示影响对昆虫的吸引力，增加传粉者的访花次数以及每次访花在花粉交换方面的效率，从而影响植物的繁殖成功率。在此，我们进行了一项原位操纵实验，以研究花的形态改变是否会影响 和 自然兰花种群的繁殖成功率。我们根据移除/沉积的花粉块和果实产量，估计了三个处理组（花管拆解、唇瓣切割和胼胝体表面涂抹）的雄性和雌性繁殖成功率。结果表明，表型改变对两个受试物种的繁殖成功率有相反的影响。实际上，在 中，花瓣和萼片的分离显著提高了繁殖成功率，而由于胼胝体涂抹和唇瓣移除，繁殖成功率降低。相反， 的未处理植株在移除和沉积的花粉块数量以及坐果率方面显著高于处理过的植株。 和 之间的差异与受试物种不同的授粉策略一致。 表现出庇护模仿策略，因此，隧道状花冠的拆解不允许昆虫将花朵用作避难所，而 是一种性欺骗兰花，因此花朵的开放使胼胝体更易见（在更远的距离可见），增加了对传粉者的吸引力。本研究提供了证据，表明传粉者对花表型的实验性改变非常敏感，这与对单个花部特征存在显著选择一致。我们对展示变化对传粉者访花影响的实验研究为具有庇护模仿策略的兰花花形态进化提供了见解。
