My research broadly centres on exploring fundamental processes in plant evolutionary ecology using molecular tools, with a specific focus on:
- Host specificity in parasitic plants and how this can drive speciation.
- Novel ecological processes driving speciation in carnivorous Nepenthes pitcher plants.
- Taxonomic circumscription of the Mediterranean Basin floristic region.
I am also responsible for Public Engagement linked to research at the Botanic Garden and Arboretum in collaboration with the Department of Plant Sciences.
Speciation in parasitic plants
The evolutionary biology of parasitic plants remained obscure for centuries. This is because the evolutionary shift to parasitism was associated with a degeneration of morphological features traditionally used in plant classification. Molecular phylogenetic techniques have now elucidated the evolutionary relationships between parasitic plants and their photosynthetic ancestors. However the interspecific relationships within groups of parasitic plants, and the processes underpinning their speciation, still receive inadequate systematic attention.
We have used a combined approach employing molecular, bioassay and histological data to show that host specificity underlies genetic divergence in the parasitic plant Orobanche minor (common broomrape). Morphologically cryptic species isolated on specific hosts have been overlooked in the complex Orobanche genus. Our work indicates that host-driven speciation may be an important evolutionary process in parasitic plants – one the most curious and poorly understood groups in the plant kingdom.
I am also interested in the ex situ cultivation of parasitic plants. Many are rare in the wild yet are infrequently seen in living collections in botanic gardens. We will initiate a parasitic plant propagation programme at Oxford Botanic Garden. This will be an important tool in the conservation of parasitic plants.
Speciation in carnivorous plants
This is a new project in which we will explore divergence in pitcher form and function linked to niche and nutrient sequestration. Nepenthes is a tropical genus of carnivorous pitcher plants with an extraordinary diversity of pitcher morphologies. In collaboration with Dr Ulrike Bauer at the University of Bristol, and Prof. Professor Dmitry Filatov and Prof. Simon Hiscock at Oxford Plant Sciences, we will explore the molecular basis for divergent evolution in the genus Nepenthes.
Mediterranean Basin floristic region
The Mediterranean Basin has one of the world’s richest floras. Indeed, up to 10% of all vascular plants occur in the Mediterranean Basin, which represents just 1.6% of the Earth’s surface. This large area has a complex and varied geology and topography but is united by its typically Mediterranean climate of hot, dry summers and mild, wet winters. I am interested in developing floras to circumscribe this very rich floristic region, particularly with a view to delineating complex taxonomic groups such as Orobanche.
Building public engagement into the design and conduct of research is becoming increasingly crucial in the work we do. The University of Oxford is committed to embedding high quality and innovative public engagement as an integral part of our research culture. In line with this, Oxford Botanic Garden and Harcourt Arboretum are building a Public Engagement strategy, in collaboration with the Department of Plant Sciences. This strategy is designed to inform and inspire the public e.g. through participation in festivals, talks and presentations, and digital engagement.