Consequences of a nectar yeast for pollinator preference and performance
Consequences of a nectar yeast for pollinator preference and performance
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DOI：
10.1111/1365-2435.12762
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发表时间：
2017-03-01
影响因子：
5.2
通讯作者：
Irwin, Rebecca E.
中科院分区：
文献类型：
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作者：
Schaeffer, Robert N.;Mei, Yu Zhu;Irwin, Rebecca E.
传粉者利用不同颜色、气味和回报质量的花卉资源。这些特征的变化，包括花蜜奖励，以及与花蜜质量相关的线索，可以影响传粉者的觅食决定，从而影响传粉者的繁殖成功。花蜜通常会受到微生物的定植，这些微生物能够影响对传粉者的吸引力和适应性很重要的一套性状；然而，微生物的存在与传粉者偏好和表现的变化之间的联系仍然很少。本文以常见的东部大黄蜂（Bombus impatiens）和分布广泛的花蜜酵母（Metschnikowia reukaufii）为研究对象，研究了一种寄生于花蜜中的微生物对传粉昆虫觅食行为和繁殖的影响。采用选择性和非选择性行为和摄食分析相结合的方法，我们控制了花粉中M.reukaufii的存在和生存能力，并评估了大黄蜂的觅食和繁殖反应。Bombus impatiens工人对酵母的存在有积极的反应。接受过将酵母菌与花朵颜色联系起来的训练的采集者在接受颜色辨别测试时，访问了接种了酵母菌的花朵的比例显著提高。此外，初次接触花蜜酵母的觅食者在初始觅食回合中加入了更多接种了酵母的花，当出现一个新的花阵列时。此外，与未接种酵母的花朵相比，蜜蜂在接种酵母的花朵上花费的觅食时间明显更长。然而，当我们在无蜂王的工蜂中控制酵母的存在和活力时，我们发现酵母对大黄蜂繁殖的组成部分没有影响，比如产卵的开始和产卵的数量。即使在花粉限制的条件下，酵母的这种作用的缺乏仍然存在。综上所述，这些结果表明花蜜酵母可以增强花的信号并改变传粉者在单个花上的觅食行为，尽管它们可能不会直接影响传粉者的表现。因此，蜜酵母可能在传粉媒介的觅食行为中发挥重要作用，从而影响植物的适应性和花性状的进化。
Pollinators utilize floral resources that vary in colour, scent and reward quality. Variation in such traits, including nectar rewards, in addition to cues associated with their quality, can influence pollinator foraging decisions with consequences for pollinator reproductive success. Nectar is commonly subject to colonization by micro-organisms capable of affecting a suite of traits important for pollinator attraction and fitness; yet, links between microbial presence and changes in pollinator preference and performance remain few. Here, we evaluated the effects of a nectar-inhabiting micro-organism on pollinator foraging behaviour and reproduction using the common eastern bumblebee Bombus impatiens and the cosmopolitan nectar yeast Metschnikowia reukaufii. Using a combination of choice and no-choice behavioural and feeding assays, we manipulated the presence and viability of M.reukaufii in nectar and assessed bumblebee foraging and reproductive responses.Bombus impatiens workers responded positively to the presence of yeasts. Foragers trained to associate yeast presence with flower colour visited a significantly greater proportion of flowers inoculated with yeast when subject to a colour discrimination test. Moreover, foragers naive to nectar yeasts incorporated more yeast-inoculated flowers into initial foraging bouts when presented with a novel floral array. In addition, bees spent significantly longer foraging on yeast-inoculated flowers compared to yeast-free flowers. However, when we manipulated yeast presence and viability in microcolonies of queenless workers, we found no effect of yeast on components of bumblebee reproduction, such as initiation of egg laying and number of eggs laid. This lack of an effect of yeast persisted even under conditions of pollen limitation. Taken together, these results suggest that nectar yeasts can enhance floral signalling and alter pollinator foraging behaviour at individual flowers, though they may not directly affect pollinator performance. Thus, nectar yeasts may play a significant role in mediating pollinator foraging behaviour, with consequences for plant fitness and evolution of floral traits.