Title : Arbuscular mycorrhiza and salicylic acid co-synergism: Potential biological tool in amelioration of salt stress in chickpea (cicer arietinum L.) genotypes
Abstract:
Salicylic acid (SA) and Arbuscular mycorrhiza (AM- Rhizophagus irregularis) have a potential to eliminate adverse effects of salt stress. Moreover, SA has been recently reported to play a key role in AM-symbiosis. However, the underline mechanisms behind the impact of SA seed priming on various AM attributes and resultant salt tolerance needs detailed investigations. Studies were aimed to understand the impact of SA seed priming (0.5 mM) on various AM attributes and their interactive influence in enhancing salt tolerance in chickpea genotypes (tolerant-PBG 5, sensitive-BG 256; NaCl 0, 4, 6, 8 dS m-1). Results indicated synergism between SA and R. irregularis as depicted by enhanced % colonization and increase in arbuscule as well as vesicle formation; which was more in PBG 5 than BG 256. Salt stress negatively affected various AM-attributes, growth, nutrient uptake (N, P, K), disturbed ion-equilibrium, modulates carbohydrate metabolism and ultimately leading to declined seed yield with more negative effects in BG 256 than PBG 5. Both SA or/and R. irregularis inoculations improved root as well as shoot dry weights; R. irregularis being more effective in improving root biomass and root to shoot ratio. SA decreased Na+ uptake in the roots along with its translocation to shoots which helped in maintaining ion-homeostasis more positively than R. irregularis inoculations. In addition, SA priming was highly effective in reducing flower abortion, improving pod and seed formation and ultimate harvest index by strengthening the carbohydrate metabolism with additive effects under combined treatments (+SA+AM). Study concluded that SA seed priming induced enhancement in R. irregularis-symbiosis can be a potential co-synergic strategy in achieving sustainable production of chickpea genotypes under salt stress.
