Skip Navigation


AOBPreview originally published online on August 12, 2005
Annals of Botany 2005 96(5):931-938; doi:10.1093/aob/mci245
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow Content Select
Right arrow All Versions of this Article:
96/5/931    most recent
mci245v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by SUGIYAMA, S.-I.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by SUGIYAMA, S.-I.
Agricola
Right arrow Articles by SUGIYAMA, S.-I.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?


© The Author 2005. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org

Polyploidy and Cellular Mechanisms Changing Leaf Size: Comparison of Diploid and Autotetraploid Populations in Two Species of Lolium

SHU-ICHI SUGIYAMA*

Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki 036-8561, Japan

* For correspondence. E-mail sugi{at}cc.hirosaki-u.ac.jp

Received: 26 March 2005    Returned for revision: 24 May 2005    Accepted: 23 June 2005    Published electronically: 12 August 2005

• Background and Aims Growth and development of plant organs, including leaves, depend on cell division and expansion. Leaf size is increased by greater cell ploidy, but the mechanism of this effect is poorly understood. Therefore, in this study, the role of cell division and expansion in the increase of leaf size caused by polyploidy was examined by comparing various cell parameters of the mesophyll layer of developing leaves of diploid and autotetraploid cultivars of two grass species, Lolium perenne and L. multiflorum.

• Methods Three cultivars of each ploidy level of both species were grown under pot conditions in a controlled growth chamber, and leaf elongation rate and the cell length profile at the leaf base were measured on six plants in each cultivar. Cell parameters related to division and elongation activities were calculated by a kinematic method.

• Key Results Tetraploid cultivars had faster leaf elongation rates than did diploid cultivars in both species, resulting in longer leaves, mainly due to their longer mature cells. Epidermal and mesophyll cells differed 20-fold in length, but were both greater in the tetraploid cultivars of both species. The increase in cell length of the tetraploid cultivars was caused by a faster cell elongation rate, not by a longer period of cell elongation. There were no significant differences between cell division parameters, such as cell production rate and cell cycle time, in the diploid and tetraploid cultivars.

• Conclusion The results demonstrated clearly that polyploidy increases leaf size mainly by increasing the cell elongation rate, but not the duration of the period of elongation, and thus increases final cell size.

Key words: Cell division, cell elongation, kinematic method, leaf elongation rate, leaf size, Lolium, mesophyll cells, tetraploid


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.