Chemical composition of leaves and structure of photosynthetic apparatus in aquatic higher plants |
| |
Authors: | D A Ronzhina L A Ivanov V I P’yankov |
| |
Institution: | (1) Institute of Natural Resources and Agrobiology of Salamanca, CSIC, Apartado 257, E-37071 Salamanca, Spain;(2) Present address: Department of Agrochemistry and Soil Science, Agricultural University, 12 Mendeleev Street, 4004 Plovdiv, Bulgaria; |
| |
Abstract: | Chemical composition of leaves (the content of carbon, nitrogen, nonstructural carbohydrates, organic acids, mineral substances,
and water) and the structure of photosynthetic apparatus (specific leaf weight, cell volume, and the number of cells per unit
leaf area) were investigated for 18 species of aquatic plants featuring various degrees of contact with aqueous environment
and sediment. The rooted hydrophytes with floating leaves were characterized by comparatively high content of carbon and nitrogen
(437 and 37 mg/g dry wt, respectively) and by low concentration of nonstructural carbohydrates, mineral substances, and organic
acids (161, 54, and 60 mg/g dry wt, respectively). Unlike rooted plants, the free-floating nonrooted hydrophytes had characteristically
higher content of nonstructural polysaccharides and mineral substances (by a factor of 1.3 and 1.6, respectively), while the
leaf nitrogen content was 1.4 times lower, and the proportion of soluble carbohydrates in the total content of nonstructural
carbohydrates was rather low (9%). The chemical composition of leaves in submerged rooted hydrophytes was intermediate between
those for rooted hydrophytes with floating leaves and for nonrooted free plants. We found reliable positive correlations between
the volume of photosynthesizing cells and the leaf content of organic acids (r = 0.69), as well as between specific leaf weight, the number of photosynthesizing cells per unit leaf area, and carbon content
(r = 0.67 and r = 0.62, respectively). The content of nitrogen and nonstructural carbohydrates in hydrophytes was unrelated to structural
characteristics of photosynthetic apparatus and depended on the absence or presence of plant attachment to the sediment. It
is concluded that the structural traits of photosynthetic apparatus and the leaf chemical composition in hydrophytes featuring
different degrees of plant contact with water and sediment reflect the specificity of plant adaptation to complex conditions
of their habitats. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|