Leaf expansion in Rhamnus alaternus L. by leaf morphological, anatomical and physiological analysis |
| |
Authors: | Laura Varone Loretta Gratani |
| |
Institution: | (1) Department of Plant Biology, Sapienza University of Rome, P.le A. Moro, 5 00185 Rome, Italy |
| |
Abstract: | Morphological, anatomical and physiological traits of Rhamnus alaternus during leaf expansion were analysed. Bud break occurred when mean air temperature was 14.1 ± 1.2°C, and it was immediately
followed by the increase of leaf area and leaf dry mass. The highest leaf expansion rates happened during the first 22 days
of the process. Leaf area and leaf dry mass reached the steady-state value 46 and 62 days after bud break, respectively. Net
photosynthesis increased from bud break to full leaf expansion, and total chlorophyll content had the same trend, confirmed
by the correlation between the two variables. Leaf dark respiration peaked during the first 11 days of leaf expansion, then
decreased and reached a steady-state value 34 days after bud break. R. alaternus completed cell division and cell enlargement of the epidermal tissue 28 days after bud break, and the ones of the mesophyll
tissue at full leaf expansion. The results underline that morphological, anatomical and physiological leaf traits in R. alaternus are indicative of a less sclerophyllous species (i.e. higher specific leaf area) compared with other Mediterranean evergreen
species. Moreover, the higher fraction of mesophyll volume occupied by the intercellular air spaces, and the ability to end
the leaf expansion process before air temperature might be a limiting factor, makes R. alaternus closer to the mesophyte species. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|