Shoot density of<Emphasis Type="Italic"> Carex rostrata</Emphasis> Stokes in relation to internal carbon:nitrogen balance |
| |
Authors: | T Saarinen P Haansuu |
| |
Institution: | (1) Department of Ecology and Systematics, University of Helsinki, Unioninkatu 44, P.O. Box 7, FIN-00014 Helsinki, Finland e-mail: Timo.Saarinen@Helsinki.fi Fax: +358-9-1918656, FI |
| |
Abstract: | Initiation of new shoots originating from basal meristems of older shoots of Carex rostrata was studied in relation to the internal carbon/nitrogen balance. In a greenhouse experiment, individual shoots with a vigorous
formation of a new shoot contained the highest concentrations of free amino acids (FAA) and the lowest concentrations of total
nonstructural carbohydrates (TNC), resulting in a low TNC/FAA ratio. Thus shoots with high availability of nitrogenous compounds
in relation to carbohydrates started growing a new shoot. The results suggest that TNC/FAA ratios could affect shoot densities.
Field measurements supported this view: TNC/FAA ratios were lower in a mesotrophic site with a high density of shoots than
in an oligotrophic site with a low density of shoots. Compared with roots, TNC/FAA ratios of shoots seemed to be more decisive
both in the greenhouse experiment and in the field. In the greenhouse experiment, initiation of new shoots was measured in
fragmented shoots of Carex having no intraclonal connections. Even if physiological integration was lacking due to fragmentation, shoot initiation was
efficiently controlled in relation to the internal carbon/nitrogen balance.
Received: 14 May 1998 / Accepted: 25 August 1999 |
| |
Keywords: | Free amino acids Growth triggering Nonstructural carbohydrates Shoot growth TNC/FAA ratio |
本文献已被 SpringerLink 等数据库收录! |
|