Abstract
In saline soil conditions the availability and uptake of Ca2+ is reduced that results in the loss of membrane integrity and other
disorders associated with Ca2+ deficiency in plants. A wheat genotype efficient in uptake and utilization of calcium under
saline conditions may be better able to withstand saline conditions in the field. Very little information is available on wheat
response to salinity and low Ca2+ as screening of wheat genotypes has usually been done against salinity alone. The present
study was designed to evaluate the performance of different wheat genotypes against salinity at low and adequate calcium
supply. The experiment was conducted in hydroponics with four treatments including T1: non-saline with adequate Ca2+, T2:
non-saline with low Ca2+ (level of calcium was 1/4th of the adequate level), T3: saline (125 mM NaCl) with adequate Ca2+ and
T4: saline with low calcium. All the physical growth parameters including shoot length, root length, and shoot and root fresh
weights were decreased significantly due to salinity and low calcium alone as well as in combination. Reduction was more
pronounced under the combined stress of salinity and low calcium and different genotypes differed significantly in different
stress treatments for shoot and root fresh weight production. In saline treatment (T3), the genotypes 25-SAWSN-39 and 25-
SAWSN-31 showed better growth performance and accumulated lower Na+ and higher Ca2+ where as the genotypes 25-
SAWSN-35 and 25-SAWSN-47 showed less growth and had less accumulation of Ca2+ and high accumulation of Na+
. In
salinity + low calcium treatment the genotype 25-SAWSN-39 behaved as a tolerant genotype where as 25-SAWSN-31
behaved similar to the sensitive genotype and these differences were due to high accumulation of Ca2+ in 25-SAWSN-39 and
vice versa. This study shows that the salt tolerance of wheat genotypes differs with the availability and accumulation of
calcium. Certain genotypes can better uptake and utilize calcium than the others under low calcium supply which improves
their salt tolerance under saline conditions.
