Pericarp Loosening and Reduced Lipid Peroxidation Enhances Spinach Seed Performance and Biomass Production Under Normal and Saline Conditions

Abstract

Spinach seeds show low germination percentage and speed due to pericarp imposed physical and chemical hindrance; the problem is further aggravated under saline conditions. To assess seed vigor and repress salinity induced lipid peroxidation, seeds of spinach cultivar 'Desi Palak' were subjected to various treatments viz., soaking in distilled water (for 4 h), washing of seeds with bleach i.e. sodium hypochlorite (for 10 min, 50% of commercial grade), seed priming (30 h) using distilled water i.e. hydropriming (with or without soaking), kinetin (25 ppm, after bleach and soaking; hereafter mentioned as kinetin only for simplicity) or Indole-3-Acetic Acid (IAA 100 ppm, after bleach and soaking; hereafter mentioned as IAA only for simplicity). The effect of seed treatments on seed vigor and salinity tolerance was evaluated through germination test (at 0, 50, 100, 150, and 200 mM NaCl induced salinity) and emergence test (at 0 and 200 mM NaCl induced salinity). Seed priming using IAA showed better final germination and emergence percentage, germination index, germination and emergence energy, seedling biomass, chlorophyll contents and vigor index than control and other seed treatments. All parameters were negatively affected by salinity but were altered to significantly lesser extent in seeds primed with distilled water or IAA, especially IAA at higher (200 mM) salinity levels. Bleach and soaking treatments seemed to soften the pericarp as evident by enhanced germination/emergence, germination energy and index, while reducing mean germination/emergence time. Further seed enhancement and increased biomass production in IAA or hydro-primed seeds (after bleach and soaking) can be attributed to reduced lipid peroxidation as evidenced by low MDA contents in seeds primed with IAA and distilled water, particularly under saline conditions.

Seed priming with seaweed extract mitigate heat stress in spinach: effect on germination, seedling growth and antioxidant capacity

“…This technique stimulates pregermination metabolic processes, increases the antioxidant system activity and the repair of membranes (Masondo et al 2018) under abiotic stress. Under conditions of heat stress, seed priming was effective on melon (Lira et al 2015), onion (Murili et al 2016), pepper (Alqui et al 2014), spinach (Ziaf et al 2017) and other crops.…”