| Salicylic acid (SA) is part of a signaling pathway that is induced by a number of biotic and abiotic stresses. It has been recognized as an endogenous regulatory signal in plants. In order to study the effect of different concentrations of SA on germination, growth and some physiological parameters in chickpea (Cicer arietinum L.) two genotypes (MCC414, MCC361) under drought stress conditions, two experiments were arranged as a factorial experiment, based on completely randomized design with three replications. In the first part of this study, the effect of drought stress by PEG (0, -4, -8 and -12 bar) and SA (0, 0.25, 0.5 and 0.75 mM) was investigated on two chickpea genotypes (MCC414, MCC361) at germination and seedling growth stages. In the second part of study, the effect of different concentrations of SA (0, 0.5 and 1 mM) and two levels of drought stress (25% and 100% field capacity) were evaluated on two chickpea genotypes (MCC414, MCC361) in growth and some physiological parameters. Solution of salicylic acid at 0.5 and 1 mM were sprayed on leaves at interval of 15, 25 and 35 days after sowing. Control plants were sprayed with distilled water. Results showed that SA had significant and negative impact on rate and percentage of germination, but improved coleoptiles length, ratio of radicle to coleoptile length and radical dry weight. In the second experiment, results showed that the drought stress reduced shoot dry weight, root dry weight, leaf area, root length, root area and total chlorophyll, significantly (p≤ 0.05). It was found that application of salicylic acid enhanced root length and diameter in comparison with control. Results showed that SA (0.5 mM) increased leaf water potential, significantly. Drought stress decreased leaf water potential in both genotypes, significantly (p≤0.05). Stomatal resistance was significantly increased under drought stress but SA had no appreciable effect on stomatal resistance. Results suggested that, SA (0.5 and 1 mM) can considerably alleviate leaf water potential under drought stress. Therefore, it was concluded that application of salicylic acid can protect plants against drought stress. Also MCC361 genotype was more tolerant than MCC414 genotype in drought stress condition. |
