Cross-tolerance Physiology of Chickpea (Cicer arietinum L.) Genotypes under Combined Salinity and High Temperature Stress Condition

Abstract

Background: Chickpea at seedling stage is highly sensitive to salinity and high temperature stress. Many studies explained plant responses under independent salinity and high temperature stress, but very little findings had revealed the combined effects of these two stresses on plants. So, the present experiment was aimed to study the response of chickpea genotypes for growth parameters and stress tolerance indices at seedling stage under individual and combined salinity and high temperature stress.Methods: A laboratory experiment during rabi season of 2018-2019 was conducted with thirty chickpea genotypes by comparing their responses under different salinity stresses i.e. EC 4.0 dSm-1 and 8.0 dSm-1 and high temperature (37°C). Seedling growth parameters i.e. germination percentage, vigour index and seedling dry weight along with stress tolerance indices like yield stability index and tolerance index were measured for 10-day-old seedlings.Result: The results revealed genotypic variations for all the parameters, based on which the genotypes KPG-59, IPC 2013-74 and NDG 15-6 were identified as tolerant, whereas KWR-108, BG-3075 and BG-3076 as susceptible. Interestingly, the results also showed that the tolerant genotypes exhibited maximum cross-tolerance at highest level of stress (T5) for germination percentage and vigour index, over control (T0), which might be attributed to their acclimatization while facing different stresses during early growth. So, the genotypic variations in chickpea for these parameters at germination stage might be good criteria for selection of tolerant genotypes under salinity and high temperature individually and also when combined.