Effect of salinization of soil on emergence, growth and survival of seedlings of Cordia rothii

Abstract Effects of salinization of soil on emergence, growth and physiological attributes of seedlings of Cordia rothii Roem. and Schult. (Ehretiaceae) were studied. A mixture of chlorides and sulfates of Na, K, Ca and Mg was added to the soil and salinity was maintained at 4.8, 6.2, 8.1, 10.6 and 12.0 dS m−1. A negative relationship between percent seed germination and salt concentration was obtained. Seedlings did not emerge when soil salinity exceeded 10.6 dS m−1. Results suggested that this tree species is salt tolerant at the seed germination stage. Seedlings survived and grew up to soil salinity of 10.6 dS m−1 and eventually this species is salt tolerant at the seedling stage too. Elongation of stem and root was retarded by increasing salt stress. However, this species has a tendency for rapid root penetration and roots are able to extract water from very dry saline soil (6.8% moisture). Among the tissues, young roots and stem were most tolerant to salt stress and were followed by leaf and old roots successively. Production of young roots and death of old roots were found to be continuous and plants apparently use this process as an avoidance mechanism to remove excess ions and delay onset of ion accumulation in this tissue. This phenomenon, designated “fine root turnover” assumes an importance to the mechanisms of salt tolerance. The ability of this plant to thrive in dry regions is further conferred by the xeromorphic features of its leaves.

[1]  R. Munns Physiological processes limiting plant growth in saline soils: some dogmas and hypotheses , 1993 .

[2]  A. Pandey,et al.  Effect of increasing salt concentration on emergence, growth and survival of seedlings of Salvadora oleoides (Salvadoraceae) , 2002 .

[3]  H. E. Hayward,et al.  A Method for Measuring the Effects of Soil Salinity on Seed Germination with Observations on Several Crop Plants1 , 1949 .

[4]  H. Barrs,et al.  A Re-Examination of the Relative Turgidity Technique for Estimating Water Deficits in Leaves , 1962 .

[5]  I. C. Gupta,et al.  Saline Wastelands Environment and Plant Growth , 1997 .

[6]  J. Etherington Penetration of Dry Soil by Roots of Dactylis glomerata L. Clones Derived from Well-Drained and Poorly Drained Soils , 1987 .

[7]  A. Pandey,et al.  EFFECT OF CHLORIDE SALINITY ON SURVIVAL AND GROWTH OF PROSOPIS CHILENSIS SEEDLINGS , 1997 .

[8]  J. P. Grime,et al.  A comparative study of root development using a simulated rock crevice , 1984 .

[9]  L. Bernstein OSMOTIC ADJUSTMENT OF PLANTS TO SALINE MEDIA. I. STEADY STATE , 1961 .

[10]  A. Pandey,et al.  Effect of Salts on Germination of Seeds and Growth of Young Plants of Hordeum vulgare, Triticum aestivum, Cicer arietinum and Brassica juncea , 2000 .

[11]  A. Pandey,et al.  Desertification : a case study from Saurashtra region of Gujarat state of India , 1999 .

[12]  Paul J. Kramer,et al.  Water Relations of Plants , 1983 .

[13]  R. Dubey,et al.  Influence of NaCl salinity on the behaviour of protease, aminopeptidase and carboxypeptidase in rice seedlings in relation to salt tolerance. , 1990 .

[14]  C. Guy,et al.  Effects of increasing NaCl concentration on stem elongation, dry mass production, and macro- and micro-nutrient accumulation in Poncirus trifoliata , 2000 .

[15]  J. C. Shickluna,et al.  Soils. An Introduction to Soils and Plant Growth , 1972 .

[16]  P. Curtis,et al.  The Role of Leaf Area Development and Photosynthetic Capacity in Determining Growth of Kenaf under Moderate Salt Stress , 1986 .

[17]  L. M. Thompson,et al.  Soils and Soil Fertility , 1973 .

[18]  J. B. Reid,et al.  Response of eucalypt species to drought , 1989 .

[19]  P. C. Sharma,et al.  Salinity-fertility interaction on growth, mineral composition and nitrogen metabolism of Indian Mustard , 1993 .

[20]  M. Ashraf Breeding for Salinity Tolerance in Plants , 1994 .