HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (22) Citing Articles via Google Scholar Google Scholar Articles by Le Roux, L. G. Articles by Kellogg, E. A. Search for Related Content PubMed PubMed Citation Articles by Le Roux, L. G. Articles by Kellogg, E. A. Agricola Articles by Le Roux, L. G. Articles by Kellogg, E. A.

Floral development and the formation of unisexual spikelets in the Andropogoneae (Poaceae)¹

Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138-2020

We investigated spikelet development in four distantly related species of the grass tribe Andropogoneae to determine whether spikelet development and the formation of unisexual florets are uniform throughout the tribe. We studied development in Bothriochloa bladhii, Coelorachis aurita, Heteropogon contortus, and Hyparrhenia hirta, and compared these with Panicum, a member of the sister tribe Paniceae. Many aspects of spikelet development in the species we have studied correlate with what is already known for Tripsacum and maize (both Andropogoneae), despite variation in how unisexual florets are distributed on the plant. The formation of unisexual spikelets is also uniform. All florets initiate both pistil and stamen primordia. In florets destined to be male, cell death occurs in the subepidermal layers of the gynoecium after the formation of a gynoecial ridge. In florets destined to be female, there is no apparent cell death in the stamens, but growth ceases after anther formation. The similarity in spikelet development and the formation of unisexual florets point to a common genetic mechanism for sex determination throughout the Andropogoneae and possibly the entire Panicoideae. Use of a cell death pathway to cause gynoecial abortion may be the basis of one morphological character that defines the subfamily.

Key Words: andromonoecy • Andropogoneae • floral development • maize • monoecy • Poaceae • Tripsacum • unisexuality

This article has been cited by other articles:

				M. S. Kinney, J. T. Columbus, and E. A. Friar Unisexual flower, spikelet, and inflorescence development in monoecious/dioecious Bouteloua dimorpha (Poaceae, Chloridoideae) Am. J. Botany, February 1, 2008; 95(2): 123 - 132. [Abstract] [Full Text] [PDF]

				E. Bortiri and S. Hake Flowering and determinacy in maize J. Exp. Bot., March 3, 2007; (2007) erm015v1. [Abstract] [Full Text] [PDF]

				R. Reinheimer, R. Pozner, and A. C. Vegetti Inflorescence, spikelet, and floral development in Panicum maximum and Urochloa plantaginea (Poaceae) Am. J. Botany, April 1, 2005; 92(4): 565 - 575. [Abstract] [Full Text] [PDF]

				A. R. Orr and M. D. Sundberg Inflorescence development in a new teosinte: Zea nicaraguensis (Poaceae) Am. J. Botany, February 1, 2004; 91(2): 165 - 173. [Abstract] [Full Text] [PDF]

				A. R. Orr, K. Mullen, D. Klaahsen, and M. D. Sundberg Inflorescence development in a high-altitude annual Mexican teosinte (Poaceae) Am. J. Botany, November 1, 2002; 89(11): 1730 - 1740. [Abstract] [Full Text] [PDF]

				L. M. Giussani, J. H. Cota-Sanchez, F. O. Zuloaga, and E. A. Kellogg A molecular phylogeny of the grass subfamily Panicoideae (Poaceae) shows multiple origins of C4 photosynthesis Am. J. Botany, November 1, 2001; 88(11): 1993 - 2012. [Abstract] [Full Text] [PDF]

				A. R. Orr, R. Kaparthi, C. L. Dewald, and M. D. Sundberg Analysis of inflorescence organogenesis in eastern gamagrass, Tripsacum dactyloides (Poaceae): the wild type and the gynomonoecious gsf1 mutant Am. J. Botany, March 1, 2001; 88(3): 363 - 381. [Abstract] [Full Text]