Improvement of Germination Indices, Growth, and Biochemical ‎Characteristics of Indigo Seedlings under Salinity Stress due to Seed ‎Priming with Pistachio Wood Vinegar

Seed priming is one of the ways to deal with stress conditions. The current research aims to improve the germination indices of indigo against oxidative stress caused by salinity through seed priming with pistachio wood vinegar in the form of a completely randomized basic design. Non-primed (control), hydro-primed, and primed seeds with concentrations of 300 and 200 times the dilution of pistachio wood vinegar were used in salinity conditions (0, 50, 100, and 150 mM NaCl). The results showed that salinity levels significantly decreased germination percentage, germination rate, germination rate coefficient, vigor index of seedling weight, fresh and dry weight of seedling, dry matter, radicle length, and anthocyanin content and increased the average germination time, the amount of total soluble sugars, reactive oxygen species, and malondialdehyde. Seed priming with pistachio wood vinegar significantly improved germination percentage, germination speed, and vigor index of seedling weight under saline conditions and reduced the average germination time. Seed priming with 300- and 200-times dilution of pistachio wood vinegar in normal conditions and 50 mM salinity improved the morphological characteristics of seedlings compared to unprimed seeds. In addition, seed priming with pistachio wood vinegar, 300 times dilution, under salinity conditions by 100 mM reduced the content of soluble sugars and malondialdehyde, improving the biochemical status of seedlings compared to oxidative stress. In general, it seems seed priming of indigo with pistachio wood vinegar diluted 300 times is more practical and economical as a modulating agent for the adverse effects caused by salt stress.