| Autor: |
Bell, Hester L., O'Leary, James W. |
| Předmět: |
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| Zdroj: |
American Journal of Botany; Oct2003, Vol. 90 Issue 10, p1416-1424, 9p, 2 Black and White Photographs, 8 Charts |
| Abstrakt: |
Optimal growth of euhalophytes requires moderate concentrations of salt and, in dicotyledons, is associated with succulence and accumulation of Na[sup +] in plant tissues. However, reports of salt-stimulated growth in monocotyledons are rare. Relative growth rate (RGR), biomass accumulation, and water content were studied in Sporobolus virginicus (Poaceae), a C[sub 4] chloridoid grass, grown hydroponically with different concentrations of NaCl. Cation concentrations were determined by atomic absorption spectrophotometry. Optimal growth occurred at 100-150 mmol/L NaCl and was not dependent on nitrogen levels or accompanied by accumulation of Na[sup +] in leaves. Biomass accumulation and RGR in plants grown at 450 mmol/L NaCl were greater than in plants grown at 5 mmol/ L. The Na:K ratios were lower in leaves than in roots, indicating discrimination in Na[sup +] and K[sup +] transport. Secretion of Na[sup +] increased from 166.5 to 336.7 mmol · g[sup -1] dry biomass · d[sup -1] as the NaCl concentration of the nutrient solution increased from 125 mmol/L to 450 mmol/L. Water concentrations of leaves and shoots were significantly greater in plants grown at optimal levels of salinity than in plants grown at lower or higher salinities. These results demonstrate salt-stimulated growth in a monocotyledon. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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