Effect of Salinity on Germination, Growth, Yield, Ionic Balance and Solute Composition of Pigeon Pea (cajanus Cajan (l.) Millsp)

Salt tolerance of Pigeon pea (Cajanus cajan (L.) Millsp) was determined at three growth stages since it has already been observed by a number of workers that degree of salt tolerance of different crops varies with their ontogeny. Therefore, salt tolerance of three accessions, Local Arhar, ICPL-151 and ICPL-850014 of pigeon pea was assessed at germination, seedling and adult stage. It is clearly evident from this study that there was no positive correlation between the tolerance at the early growth stages and at the adult stage of pigeon pea, since no clear difference in salt tolerance of three accessions was observed at the germination and the seedling stage, whereas accessions differed considerably at the adult stage. Although increasing salt concentrations adversely affected the growth of all three accessions, ICPL-151 excelled the other two accessions in fresh and dry biomass, yield and yield components when tested at the adult stage. The tolerant accession, ICPL-151 accumulated significantly lower shoot and root Na and shoot Cl. By contrast it was higher in shoot and root K, K/ Na ratios K versus Na selectivity, soluble sugars, root starch, free amino acids and proline compared with the other two accessions. The better performance of ICPL-151 under saline conditions seems apparently due to accumulation of less Na and more K and K/Na ratio and higher concentration of proline, free amino acids and soluble sugars than the other two accessions. However, relatively greater accumulation of organic osmotica was probably not enough to decrease the osmotic potential of the tolerant accession.