Effects of seaweed (Ulva lactuca) and freshwater (Spirogyra sp.) algae extracts on the salt tolerance of the bean (Vicia faba L.)

Seed priming with algae extracts is a promising alternative to stimulate growth, development, and mitigate the harmful effects of salinity on plants. In the present study, we studied under a greenhouse, the effect of priming the seeds of bean (Vicia faba L.), with two concentrations (1% and 10%) of seaweed Ulva lactuca extract (SWE) and freshwater alga Spirogyra sp. extract, on some physiological and biochemical parameters of the bean, under four salinity levels (0, 2, 8, and 32 dS/m). The results indicated that the use of SWE and freshwater alga extract has no significant effect on proline content, total soluble sugars content, and electrolytes leakage, compared to untreated control, except for the salinity level S₂ (8 dS/m) where the use of the freshwater alga extract at a concentration of 10% aggravated the leakage of electrolytes by 56% compared to the control. In non‐saline condition, chlorophyll pigment content showed no significant variation between plants from treated and untreated seeds, but under the highest salinity level S₃ (32 dS/m), the chlorophyll pigment content was significantly improved by the use of SWE and freshwater alga extract. Overall under saline conditions, the priming in algae extracts seemed to have a positive effect on bean, which could account, at least in part, for the enhanced chlorophyll pigments content. NOVELTY IMPACT STATEMENT: The effect of seed priming of the bean by two concentrations of seaweed (Ulva lactuca) and freshwater extracts was studied. Mitigating the effect of saline stress on the physiological and biochemical parameters of the bean was targeted. The saline stress of the bean on the chlorophyll b and total chlorophyll content was improved below the highest salinity level. The use of freshwater algae extracts with the same concentration aggravated the leakage of electrolytes.