Effect of silicon and nano-selenium on the chemical characteristics of the Egyptian Senna plant (Cassia acutifolia) under the influence of salt stress

Abstract

The experiment was conducted in one of the private nurseries - Babylon province - Nile Region during the growing season of 2022-2023, on seedlings of Cassia acutifolia plant (Cassia acutifolia), one month age and homogeneous in size after transforming them into pots with a diameter of 22 cm.To study the effect of two factors, the first factor is the salinity of irrigation water (1.3dS m^-1, 5 dS m^-1, 10 dS m^-1(The second factor is spraying nano silicon and selenium at concentrations (0, 50,100) mg.L^-1 to know the extent of Cassia acutifolia plant's tolerance to salt stress, and at any concentration of salt stress the medically effective compounds of the plant increase.Evaluation of the contribution of anti-stress agents in reducing irrigation water salinity damage, improving growth and the content of medically effective compounds of Cassia acutifolia plant, and the interaction between factors on Cassia acutifolia plant in its content of active compounds.The experiment was conducted under the same environmental conditions as a factorial experiment (3×5) with a split-plot arrangement according to the Complete Randomized Blokes Design (R.C.B.D) and with three replicates, where each replicates contains 15 treatments with 5 seedlings per experimental unit. Salt stress represented the main plates and such as spraying with silicon and selenium nanoparticles in the secondary plates, and the averages were compared using the least significant difference L.S.D test at the level of 5%. The results of the experiment can be summarized as follows:Irrigation with salinity water (5 and 10) dSm-1 led to an increase in the amount of phenols, flavonoids, and proline, where the W2 treatment gave the highest content of total phenols in the leaves, reaching 0.94 mg-g^-1, dry weight.While the W2 treatment gave the highest content of flavonoids, reaching 39.50 mg-g^-1 dry weight, while the W2 treatment gave the highest proline content in the leaves, reaching 4.18 mmol/g fresh weight. Spraying with selenium and silicon significantly reduced the amount of phenols, flavonoids and proline in plant leaves.Spraying with selenium and silicon led to a significant increase in the percentage increase (nitrogen, phosphorus and potassium) in the leaves of the Cassia acutifolia plant. As for the interaction between the experimental factors, salt stress, silicon, and selenium, it reduced the effects of salinity and increased the percentage (of nitrogen, phosphorus, and potassium). The control treatment outperformed and gave the highest percentage of nitrogen in the leaves, reaching 8.76%. The control treatment excelled and gave the highest percentage of phosphorus in the leaves, reaching 8.76%. 0.97%. The control treatment also excelled and gave the highest percentage of potassium in the leaves, reaching 1.89%. Corresponding to a decrease in (phenols, flavonoids, and proline).

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