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ION PARTITIONING, K/Ca AND K/Na RATIOS OF EUCALYPTUS CAMALDULENSIS GROWN UNDER NaCl SALINITY

T.M. QURESHI¹, M.Y. ASHRAF^1*, A. BANO² AND F. HUSSAIN¹

Abstract: Effect of NaCl salinity on growth, ion partitioning, K/Ca and K/Na ratios of four provenances of Eucalyptus camaldulensis was studied under 5 salinity levels i.e. 0, 0.5, 1.0, 1.5 and 2.0 % NaCl with five replications. It was noted that plant height, stem diameter, shoot and root fresh and dry weights were reduced in most of the provenances with the increase in NaCl concentration. However, reduction in growth was much prominent in Provenance-I and Provenance-IV. Accumulation of Na⁺ ions increased with increase in salinity levels in root and shoot in all the provenances under study. However, Provenance-II showed least accumulation. The concentration of K⁺ and Ca²⁺ decreased both in shoot and root of all the provenances due to applied NaCl. The Provenance-II maintained the highest concentration of K⁺ and Ca²⁺ both in shoot and root when exposed to NaCl salinity. Sodium chloride treatment increased the K/Ca ratio in shoot but not in root. At 2% NaCl concentration K/Ca ratio was maximum in shoot and minimum in root of all the provenances. K/Na ratio decreased both in shoot and root with the increase in NaCl concentration. At 2% NaCl concentration, however, provenance II maintained the highest K/Na ratio. It appears from the studies that Eucalyptus provenances having high K⁺ and Ca²⁺ contents may suppress the toxic effects of Na⁺ and hence could be recommended to be grown on highly salt-affected soils.

¹Salinity and Environmental Management Division, Nuclear Institute for Agriculture and Biology (NIAB), P.O. Box 128, Jhang Road, Faisalabad, Pakistan

²Department of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.