Abstract

GARCIA, Marina; MEDINA, Ernesto  and  VILLAFANE, Roberto. Ions and organic solutes accumulation in leaves of sugar cane plants growing in two salt affected commercial fields. Bioagro [online]. 2009, vol.21, n.2, pp.87-98. ISSN 1316-3361.

A field sampling was carried out to determine the relationship between the soil salinity and its ionic composition with the accumulation of ions and organic solutes in leaves of a sugarcane genotype PR692176 growing in salt-affected fields. Two commercial fields were chosen and samples of soil and leaves differing in age were sampled. In the soil samples the electrical conductivity of the saturation extract (ECe) and its saline composition were measured, and in the leaves the concentrations of Na⁺, K⁺, Ca⁺², Mg⁺², Cl^-,  SO₄^-2, soluble sugars and proline were determined. In one field MgSO₄ y Na₂SO₄ were the dominant salts, whereas NaCl was the dominant salt in the other. The concentration of salts in leaves increased with the ECe, with the highest values in the older leaves and the sheaths. In the field with NaCl as the dominant salt, the sheaths accumulated more Cl^- than the blades, and the contrary was observed in the case of Na⁺, being the Na/Cl ratio lower than one in both tissues. Leaf K⁺ concentration decreased as ECe increased.  In the soil with high content of MgSO₄  the concentration of Ca⁺² and the Ca/Mg ratio was notably reduced. The concentration of non reducing sugars and proline increased with ECe, suggesting a relationship between the foliar accumulation of these solutes and the tolerance of this genotype to saline conditions.

Keywords : Saccharum spp; saline soils; inorganic ions; soluble sugars; proline.