Malpighiales pollen evolution

This project investigates the evolution of pollen and tapetal characters in the recalcitrant order Malpighiales, and aims to contribute to improving our understanding of phylogenetic relationships within the order.

Transmission electron micrograph of the tetrad stage of pollen development of Linum suffruticosum subsp. salsoloides (Linaceae).

This is a relatively new project begun since 2006. The large rosid order Malpighiales was dramatically recircumscribed relatively recently using molecular data. It is one of the least resolved of the major angiosperm orders and more comparative data are needed to elucidate deep relationships and character evolution within the order. Pollen and tapetum characters, known to be of systematic significance in other angiosperm clades, have not hitherto been evaluated in relation to the phylogeny of Malpighiales. Initial work has focused on the parietal clade, and indicates that lalongate pollen endoapertures are a potential synapomorphy for this clade, while very small pollen size may indicate that Goupiaceae are potentially more closely related to the Lacistemaceae – Salicaceae clade than to Passifloraceae – Violaceae. Little work has been carried out previously on pollen of Violaceae (with the exception of Viola) and this has been the focus of an MSc project carried out at Kew in 2011 by Peter Mark (RBG Edinburgh) producing new data that we plan to publish as a joint paper. A collaboration with Alexis Matamoro-Vidal (Muséum national d’Histoire naturelle and Université Paris-Sud) has investigated evolutionary stasis in Euphorbiaceae pollen. Work on evaluating pollen characters in the clusioid clade of Malpighiales has begun recently at Kew.

 Furness, C.A. (2011) Comparative structure and development of pollen and tapetum in Malpighiales, with a focus on the parietal clade. International Journal of Plant Sciences: in press.
 

Matamoro-Vidal, A., Furness, C.A., Gouyon, P-H., Wurdack, K.J. & Albert, B. Stasis in Euphorbiaceae pollen: selection and constraints. Evolution: submitted.