Plant Water Relations and Proline Accumulations in Soybean Under Salt and Water Stress Environment

Abstract

The study was carried out with three soybean genotypes viz. Galarsum, BD 2331 and BARI Soybean-6 in a vinyl house of Banghabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh during January to March, 2012 to analyze leaf water status, leaf temperature, xylem exudation and proline accumulation under salt and water stress environment. Treatments included control, water shortage, 50 mM NaCl irrigation, 50 mM NaCl irrigation with water shortage, 75 mM NaCl irrigation, and 75 mM NaCl irrigation with water shortage environments. The relative water content, xylem exudation, leaf water potential of soybean plants were sharply decreased at 75 mM NaCl salt combined with water stress environment. However, these changes were lower in Galarsum and recorded 74.28 % relative water content, 7 mg hr-1 xylem exudation rate and -1.03 MPa leaf water potential. Leaf temperature was more in BD 2331 and BARI Soybean-6 than Galarsum. Galarsum accumulated higher amount of proline in leaves under salt and water stress environment. At 75 mM NaCl salt combined with water stress treatment, the highest proline content was also recorded in Galarsum (2.34 µmoles g-1 fresh weight). Plant water status and biochemical changed sharply under combined salt and water stress condition. Among the soybean genotype, Galarsum was more capable than BD 2331 and BARI Soybean-6 to manage salt under water stress environment.