Influence of GA3 (gibberellic acid) and Ca(calcium) on root trait variation and osmotic potential of linseed (Linum usitatissimum L.) under chloride-dominated salinity

Abstract

Linseed (Linum usitatissimum) is a versatile crop cultivated for its seeds, which are valuable source of ω-3 fatty acids. It adversely affected by soil salinity, as high salt levels can hinder their growth and reduce yields. To assess the potential for mitigating the adverse effects of high salinity concentrations, enhancing the resilience of  three genotypes (Shekhar, Sheela, and Kartika) of linseed plants, this research aimed to find out the impact of Gibberellic acid (GA3) and Calcium (Ca) on various aspects of root morphology, osmotic potential of linseed, under varying levels of Cl- dominated salinity. The study employed three salinity levels (0, 5, and 10 dSm-1) and exogenous application of  10−6 M GA3 and/or 10 mg CaCl2 kg-1 in potted plants.The findings indicated that increasing salinity stress significantly (p≤0.05) affected root parameters, including total surface area(43.45%), average diameter(42.06%), total projected area(44.45%),   length per volume (66.23%), root length, total root volume (73.23%), tips, forks,fine roots, and osmotic potential(66.67%). Correlations among linseed genotypes were observed between various root morphology and osmotic potential parameters. The application of GA3 and Ca effectively ameliorated the impact of salinity stress at its highest level (10 dSm-1), resulting in increased root parameters while decreasing the osmotic potential (Ψs). Both GA3 and Ca treatments significantly influenced root architecture and maintained optimal osmotic potential. The chloride-dominated salinity exerted inhibitory effects on all three genotypes’ (Shekhar, Sheela, and Kartika) root growth parameters while applying GA3 and Ca successfully mitigated these effects, enhancing root growth.