Abstract Detail

Systematics

Puente, Caroline [1], Brown, Elizabeth A. [2], Crayn, Darren M. [3].

Evolution of variable sterility and pollen diversity in the Australian Ericaceae.

The fleshy-fruited epacrids (tribe Styphelieae) comprise more than 350 species of plants. It is the largest and most widely distributed of the seven tribes within the subfamily Epacridoideae Arn. (Ericaceae Juss.). Members of this tribe are woody plants with drupaceous fruit that range from prostrate shrubs to small trees. Their habitats vary from heathlands and sandplains to montane forests. Styphelieae are morphologically very diverse and member species frequently represent an important component of the Australian native flora, particularly in southern and eastern Australia. Small numbers of Styphelieae species are also present as minor components of the vegetation in Indonesia, New Zealand, New Caledonia, New Guinea, Hawaii and other Pacific islands. Styphelieae are atypical with regards to their pollen structure. Even though the pollen grains are shed in tetrads as in the majority of the Ericaceae, they show patterns of variable sterility that range from full normal tetrads to pseudomonads, including triads, dyads, monads, or more rarely, nullads. Although the ontogeny of the pollen types has been well studied, their origin and evolution in the tribe remain unclear. We conducted a comprehensive pollen survey using SEM with the aims of characterizing the diversity of pollen morphology in the fleshiy-fruited epacrids, and assessing the homology of pollen morphological characters and structure against the molecular phylogenetic trees. Our results show that pollen morphology and patterns of variable sterility are fairly homogeneous within the tribe, but become highly variable in the recently re-circumscribed genus Styphelia. We discuss the evolution of these traits in a phylogenetic framework and the implications for the biology of the group.

1 - Smithsonian National Museum of Natural History, Botany, 10th St. & Constitution Ave. NW, Washington, DC, District of Columbia, 20560, United States
2 - National Herbarium of New South Wales, Royal Botanic Gardens Sydney, Mrs Macquaries Road, Sydney, NSW, 2000, Australia
3 - James Cook University, Cairns Campus, Australian Tropical Herbarium, Sir Robert Norman (E2) Building, PO BOX 6811, Cairns, QLD, N/A, 4870, Australia

Keywords:
Pollen
Ericaceae
Australia
Scanning Electron Microscopy.

Presentation Type: Oral Paper
Session: 12, Rosids II/Basal Asterids & Asterids I part A
Location: 102/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 4:30 PM
Number: 12012
Abstract ID:697
Candidate for Awards:None