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

(American Journal of Botany. 2009;96:979-988.) doi: 10.3732/ajb.0800299 © 2009 Botanical Society of America, Inc.

What's this?

This Article Full Text Full Text (PDF) Supplementary Data 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 Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Tate, J. A. Articles by Soltis, D. E. Search for Related Content PubMed Articles by Tate, J. A. Articles by Soltis, D. E. Agricola Articles by Tate, J. A. Articles by Soltis, D. E. Social Bookmarking                            What's this?

Synthetic polyploids of Tragopogon miscellus and T. mirus (Asteraceae): 60 Years after Ownbey’s discovery¹

² Massey University, Institute of Molecular BioSciences, Palmerston North, New Zealand ³ Botany Department, Oklahoma State University, Stillwater, Oklahoma 74078 USA ⁴ Department of Biology, University of Florida, Gainesville, Florida 32611 USA ⁵ Florida Museum of Natural History, Gainesville, Florida 32611 USA

ABSTRACT

In plants, polyploidy has been a significant evolutionary force on both recent and ancient time scales. In 1950, Ownbey reported two newly formed Tragopogon allopolyploids in the northwestern United States. We have made the first synthetic lines of T. mirus and T. miscellus using T. dubius, T. porrifolius, and T. pratensis as parents and colchicine treatment of F₁ hybrids. We also produced allotetraploids between T. porrifolius and T. pratensis, which are not known from nature. We report on the crossability between the diploids, as well as the inflorescence morphology, pollen size, meiotic behavior, and fertility of the synthetic polyploids. Morphologically, the synthetics resemble the natural polyploids with short- and long-liguled forms of T. miscellus resulting when T. pratensis and T. dubius are reciprocally crossed. Synthetic T. mirus was also formed reciprocally, but without any obvious morphological differences resulting from the direction of the cross. Of the 27 original crosses that yielded 171 hybrid individuals, 18 of these lineages have persisted to produce 386 S₁ progeny; each of these lineages has produced S₂ seed that are viable. The successful generation of these synthetic polyploids offers the opportunity for detailed comparative studies of natural and synthetic polyploids within a nonmodel system.

Key Words: allopolyploidy • Asteraceae • meiotic irregularities • synthetic polyploids • Tragopogon

Received for publication 3 September 2008. Accepted for publication 13 January 2009.

FOOTNOTES

¹ The authors thank B. Husband for advice on colchicine protocols and A. Leitch and Y. Lim for assistance with interpreting chromosome squashes. Two anonymous reviewers provided critical input on the manuscript. This research was funded by National Science Foundation grant MCB034637 to D.S., P.S., and J.T. They dedicate this work to their friend Yoong Lim who recently passed away after a courageous fight with cancer. Yoong was enthralled with polyploid evolution, and his enthusiasm for research was contagious.

⁶ Author for correspondence (j.tate{at}massey.ac.nz)

CiteULike    Complore    Connotea    Del.icio.us    Digg    Facebook    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				D.E. Soltis, R.J.A. Buggs, W.B. Barbazuk, P.S. Schnable, and P.S. Soltis On the Origins of Species: Does Evolution Repeat Itself in Polyploid Populations of Independent Origin? Cold Spring Harb Symp Quant Biol, August 17, 2009; (2009) sqb.2009.74.007v1. [Abstract] [PDF]