Polyploidy evolution in Spartina pectinata L.: neopolyploid formation and cytogeographic distribution

Kim, Su Min

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https://hdl.handle.net/2142/31911 Copy

Description

Title

Polyploidy evolution in Spartina pectinata L.: neopolyploid formation and cytogeographic distribution

Author(s)

Kim, Su Min

Issue Date

2012-06-27T21:18:53Z

Director of Research (if dissertation) or Advisor (if thesis)

Lee, DoKyoung

Department of Study

Crop Sciences

Discipline

Crop Sciences

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Prairie cordgrass (Spartina pectinata Link)
• polyploid
• flow cytometry
• cytogeographic distribution

Abstract

The next generation of bioenergy crops will probably be grown on marginal lands. Prairie cordgrass (Spartina pectinata Link) is well suited to marginal land that is not well-suited for conventional crop production. Prairie cordgrass is a tall (1-3 m), rhizomatous, C4 perennial grass, native to North America and tolerant of environmental stresses such as salinity and water fluctuations. Developing prairie cordgrass as an energy crop requires genomic information such as genomic size and ploidy level. This species is well known as a polyploid species comprising three ploidy levels of tetraploid (2n = 40), hexaploids (2n = 60), and octaploids (2n = 80) with base chromosome number of x = 10. By using flow cytometry, cytogeographic distribution of prairie cordgrass has been investigated throughout U.S. Across sampling areas, the tetraploid populations extend from the East North Central to the New England regions in U.S., while the octaploid cytotypes were mostly distributed in the west North Central regions; overlapped regions of tetraploids and octaploids were found in both the west North Central (IA and KS) and west South Central (KS) regions. The hexaploid cytotype was found in one mixed population (4x + 6x) occurring in Illinois. Polyploids often possess novel traits, such as changes in flowering time, cell size, and biomass. An increase in polyploidy resulted in a greater variability of morphological expression in mixed population (4x + 6x) occurring in Illinois. Substantial differences in the flowering time, stomatal size, and aboveground biomass were observed between tetraploids and hexaploids. The presence of ploidy mixtures in natural populations of prairie cordgrass offers unique opportunities for studying the formation and establishment of polyploidy under natural conditions considered as an ultimate step in plant evolution.

Graduation Semester

2012-05

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http://hdl.handle.net/2142/31911

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Copyright 2012 Su Min Kim

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