Early floral development of Pentaphylacaceae (Ericales) and its systematic implications

Autor(en)

Rui-Ju Zhang, Jürg Schönenberger

Abstrakt

Early floral development of four species from the genera Anneslea, Cleyera, Eurya, and Ternstroemia of Pentaphylacaceae, was studied comparatively using scanning electron microscopy. Together with earlier studies in Euryodendron and Adinandra, 6 out of 12 genera of Pentaphylacaceae have now been studied for their floral development. The usually pentamerous flowers of these taxa share a number of developmental features: the perianth organs appear in a clockwise or anticlockwise spiral sequence on the floral apex with relatively long plastochrons between successive organs, resulting in conspicuous size differences among perianth organs during early developmental stages. The early development of the usually polystemonous androecium is characterized by an indistinct ring-primordium and a mostly concave floral apex; individual stamens appear subsequently on this ring-primordium. However, further development of the androecium differs conspicuously among taxa and we describe three main developmental patterns for the family including features such as centripetal stamen whorls and stamens fascicles. Unusual features of floral development and organization of Pentaphylacaceae include: (1) a pronounced spiral sequence of organ appearance during early floral development in perianth and androecium; (2) the occurrence of paired organs in the corolla and the androecium of some species; (3) sepals and petals that are positioned opposite from each other in the genera Anneslea and Ternstroemia; and (4) a concave floral apex at the beginning of androecium development. From a systematic point of view our results clearly support a close relationship between Anneslea and Ternstroemia and also suggest a closer relationship among Adinandra, Cleyera, and Euryodendron on the one hand and between Eurya and Visnea on the other. Further, our developmental study stresses the differences between Pentaphylacaceae and Theaceae, which earlier where thought to form a natural group of plants. While high stamen numbers are achieved via centripetal pattern of stamen formation in the former family, stamens are formed centrifugally in the latter.

Organisation(en)

Department für Botanik und Biodiversitätsforschung

Externe Organisation(en)

Yunnan University, Heze University

Journal

Plant Systematics and Evolution

Band

300

Seiten

1547-1560

Anzahl der Seiten

14

ISSN

0378-2697

DOI

https://doi.org/10.1007/s00606-014-0981-4

Publikationsdatum

06-2014

Peer-reviewed

Ja

ÖFOS 2012

106008 Botanik, 106012 Evolutionsforschung, 106042 Systematische Botanik

Schlagwörter

ASJC Scopus Sachgebiete

Ecology, Evolution, Behavior and Systematics, Plant Science

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/127990c4-8d2b-4870-a363-8a8531415d57