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Effect of nitrogen source and salinity level on salt accumulation of two chickpea genotypes

Baalbaki, R.Z., Zurayk, R.A., Adlan, M.A.M., Saxena, M.C.
Journal of plant nutrition 2000 v.23 no.6 pp. 805-814
Cicer arietinum, nitrogen, salinity, salt tolerance, Rhizobium, nitrogen fixation, roots, shoots, mineral content, chlorides, sodium, potassium, nodulation, genotype, application rate, ammonium nitrate
This study aimed at investigating mechanisms of salt tolerance and ionic relations of chickpea (Cicer arietinum L.) cultivars with different nitrogen (N) sources. Two resistant genotypes, ILC-205 and ILC-1919, were subjected to four levels of salinity (0.5, 3.0, 6.0, and 9.0 dS m-1). Nitrogen sources consisted of inoculation with two resistant Rhizobium strains, CP-29 and CP-32, mineral N additions, and no N application. Data was collected on root and shoot contents of sodium (Na+) chlorine, (Cl-,) and potassium (K+), and shoot to root Na+ ratio, as well as shoot K+ to Na+ ratio. Salinity affected shoot Na+ and Cl- contents, but nodulating plants had higher shoot Na+ contents than plants supplied with mineral N. Shoot to root Na+ ratios were lower in the mineral N treatment than in nodulating treatments at 3.0 dS m-1, indicating that root compartmentalization and shoot exclusion were only possible at low salinities. Potassium levels of nodulating plant shoots were lower than those of non-nodulating plants only at low salinities. N-source significantly affected shoot K+/Na+ ratio, with nodulating plants having lower ratios than non-nodulating plants, indicating that rhizobial infection or nodule formation may lead to salt entry curtailing the selective ability of chickpea roots.