Potential of Lotus germplasm for the development of salt, aluminium and manganese tolerant pasture plants

Abstract

As part of a search for alternative legumes adapted to unfavorable edaphic conditions in southern Australian pastures, nineteen accessions from nine Lotus species were tested for tolerance to salinity and/or acidity. Four Trifolium cultivars and two Medicago cultivars with known responses to salinity and acidity were grown as controls. Salt tolerance was assessed in sand culture with NaCl as the predominant salt. The growth of accessions within the species L. maroccanus, L. tenuis, L. angustissimus, L. corniculatus and L. subbbiflorus did not significantly decrease in 120 mol m-3 NaCl. Tolerance to acid soil conditions was assessed in nutrient solutions with aluminium and manganese at pH 4.5. L. pedunculatus cv. Grasslands Maku and an accession of the winter annual, L. purshianus, were tolerant to both aluminium and manganese. The L. corniculatus accessions were intermediate in their tolerance to acidity. The responses of the Trifolium and Medicago cultivars to aluminium, manganese and salinity were similar to known field responses.