Sands Richard J, Rowntree Jennifer K
Centre for the Genetics of Ecosystem Services, Faculty of Life Sciences, The University of Manchester, Michael Smith Building, Manchester, United Kingdom.
PLoS One. 2016 Aug 23;11(8):e0161327. doi: 10.1371/journal.pone.0161327. eCollection 2016.
Wildflower mixes are often planted around field margins to provide forage for pollinators. Although seed for these mixtures is often wild-sourced, for species where agricultural cultivars are available, for example red clover (Trifolium pratense), cultivars can also be included. Previous evidence suggests that plant genetic background can have a strong influence on plant-arthropod interactions and therefore the provenance and genetic background of the plants included in wildflower mixes could impact plant-pollinator interactions. We tested the performance of five individual T. pratense cultivars against two commercially available wild-sourced T. pratense populations in terms of their ability to attract potential pollinator species (focusing on bumblebees) and their floral traits using greenhouse and garden experiments. The main bumblebee observed interacting with T. pratense was Bombus pascuorum and we found no difference in the absolute number of B. pascuorum visiting the cultivars or wild populations. However, we found variation among cultivars and between wild populations in their ability to attract bumblebees, which seems to be related to their relative investment in different floral traits. There was a positive relationship between biomass and number of inflorescences produced by the wild populations of T. pratense, which was not apparent for the cultivars. This suggests that artificial selection on the cultivars has changed the G-matrix of correlated traits. We show that agricultural cultivars of T. pratense can be as effective as wild populations at attracting pollinators such as bumblebees, but that the genetic background of both cultivars and wild populations can have a significant impact on the attractiveness of the plant to pollinators. We also show divergence in the correlated traits of T. pratense cultivars and wild populations that could lead to outbreeding depression if the plants interbreed.
野花组合通常种植在田间边缘，为传粉者提供食物。虽然这些混合物的种子通常来自野生，但对于有农业栽培品种的物种，例如红三叶草（Trifolium pratense），也可以包含栽培品种。先前的证据表明，植物遗传背景会对植物与节肢动物的相互作用产生强烈影响，因此野花组合中植物的来源和遗传背景可能会影响植物与传粉者的相互作用。我们通过温室和花园实验，测试了五个红三叶草栽培品种个体相对于两个市售野生红三叶草种群在吸引潜在传粉者物种（重点是熊蜂）的能力及其花部性状方面的表现。观察到与红三叶草相互作用的主要熊蜂是帕斯库姆熊蜂（Bombus pascuorum），我们发现访问栽培品种或野生种群的帕斯库姆熊蜂的绝对数量没有差异。然而，我们发现栽培品种之间以及野生种群之间在吸引熊蜂的能力上存在差异，这似乎与它们在不同花部性状上的相对投入有关。红三叶草野生种群产生的生物量与花序数量之间存在正相关关系，而这在栽培品种中并不明显。这表明对栽培品种的人工选择改变了相关性状的G矩阵。我们表明，红三叶草的农业栽培品种在吸引熊蜂等传粉者方面可以与野生种群一样有效，但栽培品种和野生种群的遗传背景都可能对植物对传粉者的吸引力产生重大影响。我们还表明，红三叶草栽培品种和野生种群的相关性状存在差异，如果这些植物杂交，可能会导致杂交衰退。
