title: External potassium (K(+)) application improves salinity tolerance by promoting Na(+)-exclusion, K(+)-accumulation and osmotic adjustment in contrasting peanut cultivars.
abstract: Achieving salt-tolerance is highly desirable in today's agricultural context. Apart from developing salt-tolerant cultivars, possibility lies with management options, which can improve crop yield and have significant impact on crop physiology as well. Thus present study was aimed to evaluate the ameliorative role of potassium (K(+)) in salinity tolerance of peanut. A field experiment was conducted using two differentially salt-responsive cultivars and three levels of salinity treatment (control, 2.0 dS m(-1), 4.0 dS m(-1)) along with two levels (with and without) of potassium fertilizer (0 and 30 kg K2O ha(-1)). Salinity treatment incurred significant changes in overall physiology in two peanut cultivars, though the responses varied between the tolerant and the susceptible one. External K(+) application resulted in improved salinity tolerance in terms of plant water status, biomass produced under stress, osmotic adjustment and better ionic balance. Tolerant cv. GG 2 showed better salt tolerance by excluding Na(+) from uptake and lesser accumulation in leaf tissue and relied more on organic osmolyte for osmotic adjustment. On the contrary, susceptible cv. TG 37A allowed more Na(+) to accumulate in the leaf tissue and relied more on inorganic solute for osmotic adjustment under saline condition, hence showed more susceptibility to salinity stress. Application of K(+) resulted in nullifying the negative effect of salinity stress with slightly better response in the susceptible cultivar (TG 37A). The present study identified Na(+)-exclusion as a key strategy for salt-tolerance in tolerant cv. GG 2 and also showed the ameliorating role of K(+) in salt-tolerance with varying degree of response amongst tolerant and susceptible cultivars.
authors.affiliation: ICAR-Directorate of Groundnut Research, Junagadh, 362001, Gujarat, India. Electronic address: koushikiari@gmail.com.
authors.forename: Koushik
authors.initials: K
authors.lastname: Chakraborty
authors.affiliation: ICAR-Directorate of Groundnut Research, Junagadh, 362001, Gujarat, India.
authors.forename: Debarati
authors.initials: D
authors.lastname: Bhaduri
authors.affiliation: ICAR-Directorate of Groundnut Research, Junagadh, 362001, Gujarat, India.
authors.forename: Har Narayan
authors.initials: HN
authors.lastname: Meena
authors.affiliation: ICAR-Directorate of Groundnut Research, Junagadh, 362001, Gujarat, India; ICAR-Directorate of Medicinal and Aromatic Plants Research, Anand, 387310, Gujarat, India.
authors.forename: Kuldeepsingh
authors.initials: K
authors.lastname: Kalariya
mesh_terms: D010367:Arachis / Q000187:drug effects* / Q000502:physiology; D018533:Biomass; D005838:Genotype; D009995:Osmosis / Q000187:drug effects; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000502:physiology; D018517:Plant Roots / Q000187:drug effects / Q000502:physiology; D054046:Plant Stomata / Q000187:drug effects / Q000502:physiology; D018526:Plant Transpiration / Q000187:drug effects; D011188:Potassium / Q000378:metabolism / Q000494:pharmacology*; D054712:Salinity; D055049:Salt Tolerance / Q000187:drug effects; D012964:Sodium / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological
chemical_list: D012965:Sodium Chloride; D012964:Sodium; D011188:Potassium
keywords: Amelioration; Ion homeostasis; Na(+) uptake; Osmo-regulation; Salt stress; Tissue tolerance