Identification of salt tolerance traits in sugarcane lines

Sugarcane, being a typical glycophyte, grows poorly on saline lands. Identification and utilization of salt-tolerant traits can make an important contribution to greater productivity in these areas. Nine cane lines were selected out of a vast gene pool, based upon contrasting morphological characters and screened in pots and plots at germination, formative, grand growth and maturity stages of growth under 0 (= 2.5 dSm(-1)), 7, 14 and 21 dSm(-1) levels of sodium chloride. Significant differences were seen amongst the lines and growth stages. Salt tolerance limit (EC50 value) of the lines varied considerably, being lowest (8.63 dSm(-1)) in CP-71-3002 and the highest (15.51 dSm(-1)) in CP-4333. Characters like pink and waxy-coated stem, large number and area of green leaves, greater root and shoot yield, high-tillering and ratooning potential revealed positive correlation with EC50 values, while the dark green color of leaves, prolonged time taken to leaf rolling in saline solution and increased leaf senescence under salinity were negatively correlated. Lines showing xeric characters were better able to tolerate high salinity. To conclude, tolerant lines and salt tolerance-linked traits identified here can be exploited to enhance the production of this crop in saline areas. (C) 1997 Elsevier Science B.V.