Project No.  2416

PRIORITY STANDARD PROJECT

Primary Supervisor

Dr Natalia Przelomska – University of Portsmouth

Co-Supervisor(s)

Dr Steven Dodsworth – University of London, Birkbeck

Dr John David – RHS

Dr Kálmán Könvyes – RHS

Summary

Daffodils (Narcissus) are an emblematic Spring flower, and their defining feature is the corona (trumpet/cup), which represents a novel floral organ.

Rationale: Little is known about the developmental mechanism underpinning this key structure. Previous research shows that it has homologies with the stamen whorl, but the genes that define the corona (vs. stamens or tepals) and act as a developmental switch are currently unknown. The corona in Narcissus shows remarkable variation, from the small cups of tazettas and jonquils, through to the familiar trumpets of pseudonarcissi, to bulbocodiums that have enlarged coronas and very reduced tepals. Species such as N. poeticus possess divergent coronas within their clade (a small cup with novel red pigmentation, amongst taxa with yellow trumpets). Further still, two species (N. broussonettii and N. cavanillesii) have independently lost the corona structure altogether.

Approaches:  A combination of developmental genetics and phylogenetics will be used to answer both mechanistic and macroevolutionary questions regarding the development and evolution of the corona. Comparative transcriptomics will be used to investigate the expression of genes at different stages of flower development, and identify candidate genes involved in corona specification. Candidate genes will then be investigated in a broader number of taxa/samples using a qRT-PCR approach. In tandem a high-throughput sequence dataset will be used to infer Narcissus phylogeny and reconstruct corona states.

Impact: Many cultivars have been developed that vary in the size/shape/colour of the corona, and more recently the splitting/fusion of corona segments. These aspects of corona morphology are important for both effective pollination and the breeding potential of new daffodil varieties, a significant crop worth many millions to UK industry as both bulbs and cut flowers.

Candidate: Interests in botany/horticulture, evolutionary/developmental biology, and high-throughput DNA/RNA sequencing. Relevant skills in taxonomy, microscopy, molecular biology, experience with high-throughput data analysis, R/programming.