Oxygen regulates imbibition of muskmelon seeds
1995
Yeoung, Y.R. (University of Idaho, Moscow (USA). Department of Plant, Soil and Entomological Sciences) | Wilson, D.O. Jr. | Murray, G.A.
Little information exists concerning the effect of oxygen on imbibition. This study investigated how oxygen concentration and water potential interact to affect water uptake rate of muskmelon seeds and the relationship of respiration to water uptake rate. Muskmelon seeds were immersed in polyethylene glycol (PEG) 8000 solution at different oxygen concentrations and water potentials for 10 days with or without cyanide. Under all combinations of water potential and oxygen, seeds took up water rapidly during the first day, followed by a lag phase. Radicle protrusion of whole seeds at 0 MPa and 100 % oxygen took place at 28 h. By this time, the moisture content was approximately 90 % (dw. basis). Under these conditions the lag phase was very short (20 h), followed by a rapid growth phase. No radicle protrusion occurred at water potentials less than -0.62 MPa, nor at oxygen concentrations of 80 %, and less. Water uptake was influenced by oxygen concentration and/or the presence of cyanide between about 2 and 15 h after the start of imbibition. After this period water uptake was not influenced by oxygen nor cyanide, except under conditions which triggered radicle protrusion (high oxygen). These results suggested that respiration is a major factor determining water uptake just before the plateau phase
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