Radial oxygen loss from intact roots of Halophila ovalis as a function of distance behind the root tip and shoot illumination

摘要: Abstract Radial oxygen loss (ROL) was measured as a function of distance behind the tip for roots seagrass Halophila ovalis (R.Br.) Hook f. The effects shoot illumination and leaf area on ROL were also examined porosity anatomy roots, rhizomes petioles H. . For plants taken from Swan Canning Estuary, Western Australia, porosities 15%, 27% 17%, respectively. in an O 2 -free saline medium using root-sleeving cylindrical platinum electrodes. shoots submerged aerated seawater during measurements. substantially higher when exposed to saturating light it decreased markedly dark. These findings, experiments which leaves excised, show that lost radially photosynthetically derived. Moreover, showed marked gradient along root; average maximum value 72 ng cm −2  min −1 at 0.5 cm root only 4 ng cm 3 cm, most basal position tested. data contain `a barrier ROL' more regions, adaptation shown by other workers enhance growth wetland macrophytes into anaerobic sediments.