Pattern of accumulation of some major and trace elements in salt-tolerant and salt-sensitive lines of lentil under nitrogen deficiency

The response of two lines of lentil (Lens culinaris), ILL 6796 (salt-tolerant) and ILL 6778 (salt-sensitive), to nitrogen (N) deficiency was examined under glasshouse conditions. Plants of the two lines were subjected to 56(control), 28, 14, and 7 mg N L-1 in Rorison's nutrient solution. The ILL 6796 had significantly greater dry matters of shoots and roots, and seed yield than ILL 6778 at varying external N levels of the growth medium. Concentrations of N and P in different plant parts of the two lines generally decreased with decrease in N levels of the rooting medium. By contrast, an increase in leaf calcium (Ca2+) concentrations in both lines was observed with decreasing external N levels, although root Ca2+ concentrations decreased considerably and those of seed remained unaffected. An antagonistic effect between N and Ca2+ was observed in the leaves of both lines. Magnesium (Mg2+) in the leaves and roots of both lines generally decreased, whereas those of seed remained unaffected under N deficient regimes. Comparison of lines showed that ILL 6796 had greater N in the leaves and roots, and potassium (K+) in the roots than those of ILL 6778. By contrast, ILL 6778 accumulated significantly greater Mg2+ and zinc (Zn2+) in leaves and manganese (Mn2+) in seed than ILL 6796 at the lower N levels. Of the different trace elements analyzed only iron (Fe2+), Mn2+ and Zn2+ in seed of both lines slightly increased with decrease in N level of the growth medium. The concentrations of trace elements in different plant parts of both lines did not bear any relationship with the uptake of major nutrients under N deficient regimes. It is concluded that in lentil uptake of major nutrients such as N, P, K, Ca, and Mg was perturbed due to N deficiency, but in contrast, the uptake of trace elements Fe, Mn, Zn, and copper (Cu) in the leaves and roots remained unaffected except the leaf Zn2+ in ILL 6778.