Effect of exchangeable sodium on growth, yield and ionic relations in wheat genotypes differing in sodicity resistance

Three genotypes of wheat namely Kharchia 65, CSW 540-2 (resistant) and HD 4502 (sensitive) were grown in porcelain pots containing artificially prepared sodic soils. Both the resistant genotypes showed better germination, survival, plant growth and yield, higher K and lower Na concentrations accompanied by lower Na, K ratios to comparison to the sensitive genotypes. In HD 4502, Na levels increased with sodicity as well as with the age of the leaf and the third, fourth and lower leaves were unable to survive due to lethal Na concentrations. On the contrary, no leaf in the resistant genotypes possessed Na concentrations higher than 2% whereas all the leaves of HD 4502 tended to have Na above 2% at pH 9.4 and 9.6. K concentrations declined in all the genotypes but more sharply in the sensitive one. Thus the genotypic differences in cations like Na and K along with their distribution within the plant can be used in identifying resistant genotypes and species required for breeding salt resistant crops.