Photoperiod affects growth, seed production, and biochemical composition in Salicornia species under salinity

The current study was conducted in two separate factorial experiments based on completely randomized block design with three replicates and three destructive samples for each replication. The first experiment consisted of two parts. The first part aimed to determine the effect of four photoperiod levels (10-, 12-, 14-, and 16-h daylight length) on fresh and dry mass, 1000-seed weight, and seed yield of four ecotypes of Salicornia persica (Gorgan, Central plateau, Urmia, and Bushehr) along with two Salicornia species (S. bigelovii and S. europaea L.). The second part aimed to investigate the chemical properties of the shoots and seeds of Salicornia plants under short- and long-day (10- and 16-h daylight length) photoperiod treatments. The second trial intended to test the eight levels of salinity stress (control, 10, 20, 30, 40, 50, 60, and 70 dS/m with NaCl) on seedling growth traits of three native ecotypes of S. persica (Urmia, Bushehr, and Central plateau) under the best photoperiod treatment resulting from previous experiments (16-h daylight length). The results showed that fresh mass and dry mass of Salicornia plants are promoted by long days. The maximum values of 1000-seed weight (0.41 g) and seed yield (7.19 g/plant) were obtained at 16-h daylight length for S. bigelovii. Nearly in all Salicornia plants, the maximum values of chemical traits were due to exposure to 16-h daylight length except for seed and shoot flavonoids. In the second experiment, results revealed that S. persica ecotypes positively responded to salinity levels in the range of 10-30 dS/m, while seedling growth was inhibited at 70 dS/m of salinity stress except for S. persica Central plateau.