Two clones of Agrostis stolonifera, (salt tolerant and non tolerant) were assessed for responses to NaCl and MgCl<SUB>2</SUB>-stress. Elevated supplements of Ca<SUP>2+</SUP> and M<SUP>2+</SUP> were added to the growth medium in conjunction with the imposed stress, in order to ascertain any amelioration conferred by these ions. Whole plant and callus tissues were investigated. The effect of NaCl and MgCl<SUB>2</SUB>-stress on growth, ionic relations and accumulation of nitrogenous compounds, sugars and chlorophyll was investigated. The salt marsh clone was more tolerant than the inland towards NaCl and MgCl<SUB>2</SUB>. Under the imposed stresses the salt marsh clone exhibited greater growth rates and showed a comparatively greater ability to utilize Ca<SUP>2+</SUP> and Mg<SUP>2+</SUP> in an ameliorative capacity. Whole plant tissues showed significant loss of Mg<SUP>2</SUP> (roots) and K<SUP>+</SUP> (roots and shoots) in response to NaCl. Ca<SUP>2+</SUP> and Mg<SUP>2+</SUP> ameliorated this to some extent. Both clones exhibited enhanced proline and QAC accumulation in response to salinity, however, sugar and total α-amino and concentrations did not show this significant trend. Callus tissue responses showed a parallel with those of the whole plant, with respect to salinity induced reduction of growth rate, K^+ loss and proline accumulation. However, in contrast, NaCl and MgCl_2-stressed callus tissues accumulated increased concentrations of total sugars. Soil sample solutions from Llanrhidian Salt Marsh were analysed over a twelve month period and compared with the relevant climatological data. High Mg^2+, Ca^2+ and K^+ concentrations coincided with periods of low rainfall. High Cl^- and Na^+ concentrations correlated well with low rainfall and elevated ambient temperatures.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:638789 |
| Date | January 1991 |
| Creators | Seelig, C. I. |
| Publisher | Swansea University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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