Adaptation to Excess Salts in an Alkaline Soil Population of Cynodon Dactylon (L.) Pers.

Abstract

Soils containing excess of salts occur extensively in the north-western parts of India; more and more are being added every year because of the use of brackish water for irrigation. An understanding of the basis of salt tolerance in plants is important for effectively counteracting salinity and alkalinity problems. Salt tolerance of species and varieties could be related either to an ability to limit intake of ions which are available in excessive amounts in the medium or to an ability to tolerate high internal levels of certain ions before suffering injury. As noted by Jennings (1968), comparative data are lacking on the concentrations of solutes in the plant tissues of salt-resistant species and populations grown in culture media of high osmotic potential. The present study deals with the differential response to excess salt in the medium of two populations (n = 18) of Cynodon dactylon (L.) Pers.: one from a 'normal' soil (Gangetic alluvium) at Chandigarh (latitude 30? 44' N, longitude 76? 47' E) and one from an alkaline soil at Nilokheri (about 100 km south-east of Chandigarh).