Screening pigeon pea (Cajanus cajan L.) genotypes for salinity tolerance

Pigeon pea is a major pulse, whose productivity is significantly affected by salinity. Salinization of soil is a condition, in which ions like Na+, Cl-, Ca2+, Mg2+ accumulate in the soil through irrigation water. Salinity alters the metabolic pathway of the plant, due to accumulation of various salts and thereby contributing to yield loss. In this research, salinity stress in pigeon pea genotypes was imposed in all the genotypes at a concentration of 50, 100, 150 and 200 mM NaCl. Screening was carried out by observing early growth parameters like germination percentage, root length, shoot length, fresh weight, dry weight, total seedling length and vigour index. The pigeon pea genotypes G5 (ICP 2947), G20 (ICP 14961), G3 (ICP 7380), G2 (ICP 7024) and G10 (ICP 16184) were identified as salt stress tolerant genotypes. They exhibited tolerance, despite subjecting the seedlings to varying salt concentration levels. The tolerance may be developed due to the osmotic regulation, ionic homeostasis or activation of Salt-Overly-Sensitive (SOS) pathway. As a result, the effect of induced salinity in pigeon pea genotypes would aid in selection of suitable lines for challenging saline environments. This research highlights the impact of salinity in early growth stages of pigeon pea and the response will differ with different stages of growth.