Studies on absorption of $sup 32$P, $sup 59$Fe, and $sup 45$Ca, by water- milfoil (Myriophyllum exalbescens Fernald)
A method was developed for determining uptake and translocation of mineral elements by intact submersed aquatic vascular plants in laboratory and field studies. Autoradiographs and radioactivity measurements provided direct evidence that /sup 32/P, /sup 59/Fe, and /sup 45/Ca were absorbed by the roots of Myriophyllum exalbescens and translocated to the shoot tissues. Similar evidence was obtained for absorption of /sup 32/P by the shoots and translocation to the roots. Data from experiments designed to compare the effect of substrate type (sand or muck) and the presence or absence of light showed no significant difference in the amounts of /sup 32/P absorbed by roots. Translocation of /sup 59/Fe from root to shoot tissues occurred mainly when plants were rooted in muck. /sup 45/Ca translocation from roots to shoots was greatest for plants rooted in sand and maintained in the light. Phosphorus-32 was generally distributed throughout Myriophyllum as revealed by autoradiography, with some accumulation occurring at the nodal and budding regions. /sup 59/Fe and /sup 45/Ca were not translocated as readily but some accumulation of each occurred in the stem. Phosphorus-32 absorbed by the roots of Myriophyllum was translocated to the shoot system and released to the surrounding water. Experimental evidence showed that injury to submersed hydrophytes can result in additional release of phosphate to the water. The rate of release is increased as a result of physical damage to the shoot. This provides an additional pathway for the cycling of phosphorus in freshwater environments. (auth)
- Research Organization:
- Univ. of Pittsburgh, Linesville, PA
- NSA Number:
- NSA-29-018672
- OSTI ID:
- 4367016
- Journal Information:
- Ecology, v. 55, no. 1, pp. 188-194, Other Information: Orig. Receipt Date: 30-JUN-74
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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