Growth response of Phaseolus vulgaris to varying salinity regimes

Phaseolus vulgaris tolerates low (48 mM NaCl), but not higher levels (72 and 96 mM NaCl) of salinity stress. At the low salinity stress, there is an initial delay in development (morphogenetic shift) of the leaves. Salinity affects shoot growth more than root growth. Osmotic adjustment to salt stress results in an increased water content in the leaves. Our results suggest that two major physiological traits enable the plants to tolerate salinity: (a) compensatory growth following adjustment to salinity, and (b) ability to increase both leaf area ratio (LAR) and net assimilation rate (NAR) to achieve this increased growth. These characteristics are important physiological traits which can be used in screening for potential salt-tolerant lines of beans and other crop plants.