Plant Water Relations and Osmotic Adjustment in Brassica Species under Salinity Stress

Abstract

This investigation was carried out to compare the physiological behavior of two cultivars of Brassica grown under saline irrigations. The plants treated with saline water (ECe 15 dSm -1 ) resulted in a quick development of water saturation deficit at 0.08 days after salinization (DAS) followed by a sharp decline in water potential at (0.25 DAS). Subsequently, a marked increase in diffusive resistance and a greater decrease in transpiration rate were noticed at one DAS. The response of Brassica at vegetative stage under salinization proved to be biphasic process. The first phase was characterized by rapid changes in turgor potential or volume change and the second phase represented the increase in solute concentration. Using the 'b' value (ln OP= a+b ln RWC) for judging the osmotic adjustment, both the species maintained turgor potential under salinization and thus exhibited osmotic adjustment, however, cv. HC 2 had an edge over its counterpart for higher osmotic adjustment as well as higher cell wall elasticity (less negative) during critical early phase of salinization. On the basis above findings it was concluded that both the Brassica species showed biphasic behavior during salinization, but during critical early phase of salinization cv. HC 2 showed some characters of better adaptation than cv. Kranti. (Journal of American Science 2010; 6(6):1-4). (ISSN: 1545-1003).