Physiological and biochemical responses of salt-tolerant and salt-sensitive pigeonpea genotypes to salinity
Srideepa S, Mallika R
The present study was carried out to evaluate the physiological and biochemical changes induced by salt stress in ten cultivars of Cajanus Cajan L. under laboratory conditions and to screen the salinity tolerant and sensitive cultivars based on the results obtained. The productivity of crops is not increasing in parallel with the food demand. The lower productivity is attributable to various abiotic stresses, of which increased soil salinity is one of the foremost causes. The negative effect of salinity is caused by Na+ and Cl- ions producing the critical conditions for plant survival. The obvious outcome of salinity includes membrane damage, nutrient imbalance, altered levels of growth regulators, enzymatic inhibition and improper metabolic functions, including photosynthesis which ultimately leads to plant demise. In order to overcome this problem genotypes that are resistant to salinity need to be identified for further use in crop improvement programmes. Crops vary significantly in their threshold limits of salt tolerance. A well-focused approach combining the molecular, physiological, biochemical and metabolic aspects of salt tolerance is essential to alleviate the drastic effects of salinity and develop salt-tolerant crop varieties. Ten genotypes of pigeonpea were selected for their comparative analysis under salinity stress. These were ICP939, ICP1126, ICP1279, ICP2698, ICP8793, ICP11059, ICP13011, ICP14722, ICP14900, ICP11946) collected from NBPGR, New Delhi. According to the results obtained in our study, Eight among the ten Cajanus cajan L. cultivars namely EC ICP 939, ICP2698, ICP 1126, ICP1279, ICP11059, ICP13011, ICP14722, ICP14900 were identified as salinity tolerant cultivars and two among them namely ICP 8793 and ICP11946 were identified as salinity sensitive cultivars based on their biochemical response towards salinity.