Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 - 5902]
Volume 23: 1436 - 1446. Published November 12, 2009.
Changes in growth and metabolic profile of Chickpea under salt stress
ABSTRACT
Objectives: To analyze differences in sensitivity to saline stress among kabuli and desi cultivars of chickpea.
Methodology and results: From ten genotypes of chickpea, three cultivars were screened in saline soils; two of them are kabuli (PUSA-1053, PUSA-939) and one desi types (BG-256). The seeds of the different cultivars were inoculated with Rhizobium sp. strain G-118 and the plants were grown in the greenhouse. After 12 days when symbiosis establishes, saline water of varying concentrations (0, 4, 8, 12, 16 dSm-1) NaCl, Na2SO4, CaCl2 were supplied to the seedlings. Plants were harvested at 30, 60 and 90 days after sowing (DAS) for analysis. Data were subjected to statistical analysis of variance, and the means compared by the LSD test (p<0.05). Results showed that plant growth, nodulation and nitrogenase activity were more severely affected in cultivar BG-256 under salinity treatments than cultivars PUSA-1053 and PUSA-939. Nodule mass and number was enhanced under salt stress in PUSA-1053 and PUSA-939. Phosphoenolpyruvate carboxylase (PEPCase) activity increased significantly in the nodules of tolerant cultivars under salt stress at all harvests, and this was clearly related to the salt treatments. Salinity reduced leaf chlorophyll and Rubisco activities in all the three cultivars.Conclusions: Salt stress limits photosynthetic efficiency, nitrogen fixation and carbon metabolism. Alteration in the nodular metabolism seemed to be directly responsible for nitrogen fixation by the salt tolerant cultivars. The present study reveals that under saline stress tolerant cultivars are more capable of nodulation which helps to attain higher nitrogen fixation by symbiosis than the sensitive ones.
Key words: chlorophyll pigments, nitrogenase activity, nodule, PEPCase, Rubisco
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