1. Inferring the behaviour of pollinators by molecular characterisation of pollen carriage at the population, community and landscape scales
- Author
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Ronca, Sandra
- Subjects
581.7 - Abstract
Recent developments in NextGen sequencing and DNA barcoding have been exploited to enhance capacity to study pollinator service in a focussed and holistic manner. Initial efforts focussed on developing robust molecular systems for quantification of two- and multi-species pollen mixtures recovered from pollinators. A simple twospecies system used pyrosequencing to provide quantitative information on the relative abundance of Brassica napus and B. rapa pollen. The more demanding multi-species system used rbcL barcode amplicons sequenced on the 454 XLR platform. Sequence tags allowed for all resultant sequences to be assigned to the insect from which they derived and so provide quantitative pollen carriage data. The pyrosequencing system was deployed on pollen DNA recovered from a pollinator guild collected from either the crop (B. napus) or from nearby populations of its close relative, B. rapa. The aim was to compare the propensity of each pollinator to carry crop pollen to the wild recipient over a linear transect. Surprisingly, the most studied pollinator with regards to gene flow, honey bees (Apis mellifera), was least prone to carry crop pollen to wild B. rapa. The understudied hoverflies (Syrpidae), however, often carried significant proportions of crop pollen >200 m. The 454 analysis system characterised changes in pollen carriage with phenological progression and according to species, site and gender. All factors were found to be significant in shaping pollen carriage but to differing degrees. The most striking was the extent to which migrations to other communities varied between pollinators and was most evident during a flowering transition period when resources appeared limiting. This study provides a platform for more detailed works to track pollen carriage within and between plant communities in a specific landscape as the flowering season progresses. They also provide methodological tools to test theoretical models constructed to predict pollinator behaviour on a landscape scale.
- Published
- 2010