The Role of Harmel Seed Extract and Mannitol in Inducing Genetic Variations and Drought Tolerance of Barley Varieties in Vitro

Abstract

An experiment was conducted in the Plant Tissue Culture Laboratory at the College of Agricultural Engineering Sciences, University of Baghdad during the years 2022-2023 using Plant Tissue Culture Technique, to induce genetic variations and drought tolerance in vitro for three varieties of barley: Ebaa265, Ebaa99, and Bouhoth244. The experiment included the use of an extract Harmel seeds at concentrations of (0, 3, 6, and 9) % and for a soaking period of (0, 4, 8, and 12) hours, and Mannitol at concentrations of (0, 2, 4, and 6) g.L−1 using MS (Murashige and Skoog) media. Measurements were taken of the average dry weight of callus before and after treatment with Harmel seed extract and a Random Amplified Polymorphic DNA (PCR-RAPD) test was conducted. The results showed that there were significant differences in the average dry weight of callus before and after treatment with Harmel seed extract at a concentration of 9% for a soaking period of 12 hours and with Mannitol 6 g.L−1 and the comparison treatment resulting from soaking with Harmel seed extract. The dry weight of callus before treatment with the extract reached 40.42 mg in the variety Ebaa265, is significant different of the average dry weight of callus after treatment with the extract reached 98.10 mg in the variety Bouhoth244. The PCR-RAPD with five primers (OP-A06, OP-A07, OP-A08, OP-B01 and OP-B02) examination revealed differences in the number of resulting bands and their molecular weights in the Harmel seed extract treatments and the comparison treatment, in light of the results. It can be concluded that the extract of Harmel seeds has the ability to cause genetic variations and increase the tolerance of vegetative growth to drought stress resulting from treatment with the compound Mannitol in barley.