Epidermal micromorphology in Dioon: did volcanism constrain Dioon evolution?. (31st August 2015)

• Record Type: Journal Article
• Authors: Barone Lumaga, Maria Rosaria; Coiro, Mario; Truernit, Elisabeth; Erdei, Boglárka; De Luca, Paolo
• Is Part Of: Botanical journal of the Linnean Society. Volume 179:Number 2(2015:Oct.)
• Page Start: 236
• Page End: 254
• Publication Date: 2015-08-31
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/boj.12326
• Languages: English
• ISSNs: 0024-4074

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The genus <italic>D</italic><italic>ioon</italic> occupies an important phylogenetic position as sister to the other Zamiaceae. However, its epidermal morphology is still poorly known. We employed scanning and transmission electron microscopy, confocal microscopy and light microscopy to examine the epidermal and cuticular morphology of 12 of the 14 currently recognized species of <italic>D</italic><italic>ioon</italic>, examining cultivated plants and herbarium specimens. Epidermal characters separate <italic>D</italic><italic>ioon</italic> quite clearly from the other genera of the cycads. Within the genus, the major subgroups can be distinguished by their epidermal morphology. Some characters, such as the degree of stomatal protection, reflect ecological specializations in species within the subgroups. Several epidermal characters of the crown group <italic>D</italic><italic>ioon</italic> seem to be absent in the Cenozoic fossils usually associated with the genus, which have been used as calibrations in many recent molecular dating analyses. The presence of similar characters in a Mesozoic fossil adapted to volcanic stress offers a new key in the interpretation of <italic>D</italic><italic>ioon</italic> evolution. © 2015 The Linnean Society of London, <italic>Botanical Journal of the Linnean Society</italic>, 2015, <bold>179</bold>, 236–254.</p> </abstract>