Genotypic differences in growth and nitrogen fixation among soyabean (Glycine max (L.) Merr) cultivars grown under salt stress.

Abstract

(...) During the 4-week growth period the leaves of salt-stressed sensitive cultivars howed a linear accumulation of large quantities of Cl − , accompanied by an accumulation of Ca 2+ , Mg 2+ and K + in the leaves of salt-stressed tolerant cultivars were low. The levels of Na + in the leaves of both sensitive and tolerant cultivars remained low under salt stress. Scions of tolerant cultivars grafted onto the root stock of sensitive cultivar Williams showed a typical sensitive response in terms of growth, nitrogen fixation and ionic content. In contrast, scions of sensitive cultivars grafted onto the root stocks of tolerant cultivars showed a typical tolerant response, sustaining growth and nitrogen fixation under salt stress. This confirms the primary role for the root in the regulation of ion uptake, as well as growth and nitrogen fixation, under salt stress