The use of MES buffer in early nodulation studies with annual Medicago species
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The usefulness of 2-(N-morpholino)ethanesulfonic acid (MES) to stabilize the pH of solutions in the range pH 5.5 to 7.0 during early growth and nodulation of annual Medicago (medic) species was investigated.
In the first experiment, effects of MES concentrations (0, 1, 2, 5, 10 mM) on growth and nodulation of Medicago polymorpha L. and the stability of solution pH were investigated. In the second experiment we assessed the effect of MES on the growth and nodulation of three medic species (M. truncatula Gaernt., M. polymorpha and M. murex Willd.) at a range of starting pH levels (5.5, 6.0, 6.5 and 7.0) with different concentrations of MES buffer (0, 0.5, 10 mM). In a third experiment, the effects of the concentration of extra cations and the species (K-ion or Na-ion), used as hydroxide to bring solutions containing different MES concentrations to target pH were investigated.
MES had no effect on growth at MES concentrations as high as 10 mM but nodule numbers were increased by concentrations of MES of 2 mM or greater. The presence of extra K-ion or Na-ion in solutions had no effect on plant growth or nodulation. With low MES concentrations (0.5 mM), solution pH stability was improved by daily titration and the use of a high nitrate to ammonium ratio (9 : 1) in solution. This combination of strategies maintained pH within a narrow range without effects on annual medic growth or nodulation.
Key wordsannual Medicago nodulation buffer nutrient solution pH stability 2-(N-morpholino)ethanesulfonic acid (MES)
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- Caetano-Anolles G, Lagares A and Favelukes G 1989 Adsorption of Rhizobium meliloti to alfalfa roots: Dependence on divalent cations and pH. Plant and Soil 117, 67–74.Google Scholar
- Ewing M A and Robson A D 1990 The effect of nitrogen supply on the early growth and nodulation of several annual medic species. Aust. J. Agric. Res. 41. (In press.)Google Scholar
- Howieson J G, Ewing M A and D'Antuono M F 1988 Selection for acid tolerance in Rhizobium meliloti. Plant and Soil 105, 179–188.Google Scholar
- Imsande J and Ralston E J 1981 Hydroponic growth and the non-destructive assay for dinitrogen fixation. Plant Physiol. 68, 1380–1384.Google Scholar
- Miyasaka S C, Checkai R T, Grunes D L and Norvell W A 1988 Methods for controlling pH in hydroponic culture of winter wheat forage. Agron. J. 80, 213–220.Google Scholar
- Rys G J and Phung T 1985 Nutrient solution pH control using dipolar biffers in studies of Trifolium repens L. nitrogen nutrition. J. Exp. Bot. 36, 426–431.Google Scholar