Response to salinity in Glycine. 1. G. javanica

Abstract

The brigalow lands of N.E. Australia are known to have a high salt content. Tests on soils selected from samples taken during a regional survey showed salt contents from 0.2 to 1.69 per cent. Salt tolerance is thus a useful quality for any pasture plants for these soils. Glycine javanica, which has shown promise as a pasture legume in the brigalow, was tested in two expetiments in which the salinity of a water culture was gradually increased by daily increments of salt until levels of up to 240 m-equiv. were obtained. With the highest levels of salt, yield dropped to 25 per cent of that of the controls. Nitrogen content was unaffected. Phosphorus content rose by up to 100 per cent in the roots, but did not change in the tops. The percentage of soluble nitrogen increased by more than 50 per c a t as salinity rose, indicating that protein synthesis was impaired. Adaptation to salinity stress was favoured by gradual changes in its severity and by continued exposure. There were varietal differences in the pattern of chloride distribution within the plant which require further study.