تأثير بعض منظمات النمو والمحفزات الكيميائية والفيزيائية في النمو والمحتوى الكيميائي لنبات Mentha piperita L. خارج الجسم الحي

Effect of some Growth regulators and chemical and physical stimulants on the growth and chemical content of Mentha piperita L. In vitro

This study was carried out in the Plant Tissue Culture Laboratory of the College of Agriculture – University of Karbala and HPLC analyses were completed at the White Fields Company for Investments, Environmental and Engineering Studies for the period from 1/8/2024 to 1/4/2025. The study included the use of plant tissue culture technology with the aim of establishing and multiplying the vegetative branch farms of the peppermint plant and then stimulating them to increase the production of some volatile oils with effective medical effects. The study was carried out through several independent experiments after the sterilization process: the first included the emergence of tissue cultures using different concentrations of BA and NAA (0, 1, 1.5) mg L-1 and (0, 0.1) mg L-1, respectively. The second stage was carried out by cultivating the tips of the branches obtained from the emergence stage on the MS medium prepared with different concentrations of BA and KIN (0, 1, 2, 3) mg L-1 and (0, 0.5, 1.0, 1.5) mg L-1, respectively, in the presence of a fixed concentration (0.1) mg L-1 of NAA, with the aim of obtaining the largest branches from the vegetative branch cultures. The stimulation experiment was carried out by cultivating the tips of the vegetative branches obtained from the multiplication stage and cultivating them on the MS medium prepared with different concentrations of phenylalanine and PEG (0, 1, 2, 4) mg L-1. and (0, 2, 4) mg L-1 in independent experiments with fixed concentrations of BA, KIN, and NAA under three lighting conditions. The experiments were designed according to a completely randomized design (CRD). The results of the study showed the following:
• The best combination for sterilizing peppermint seeds was sodium hypochlorite (NaOCl) at a concentration of 2% for 15 minutes, which was 0.00%.
• The best combination for interaction in terms of percentage response was at a concentration of 0.1 mg L-1 of NAA, with the highest average interaction with a concentration of 1 mg L-1 of BA reaching 80%.
• The nutrient medium prepared with BA at a concentration of 2 mg L-1 and KIN at a concentration of 1 mg L-1 recorded the highest average increase in the number of branches, height, and fresh and dry weight of the vegetative system in the multiplication stage, reaching 38.30 branches/plant-1, 12.30 cm, 19.85 mg, and 4.17 mg, respectively. • Treatment of vegetative growths with different concentrations of phenylalanine and lighting led to significant differences, as the concentration of 4 mg L-1, in interaction with colored LED, achieved the highest average for the studied traits, which included the number of vegetative branches, as well as the concentration of peroxidase enzyme, catalase enzyme, proline enzyme, Menthol compound, 2, Menthofuran, and Menthone, which reached 65.67 plant branches, 2.17 minute absorption units g-1, 3.88 minute absorption units g-1, 3.77 micrograms g-1, 39.10, 34.18, and 28.22 micrograms ml-1, respectively. As for the interaction between the concentration of 2 mg L-1 of phenylalanine with colored LED lights, it achieved the highest average in plant height, fresh and dry weight, chlorophyll concentration, carbohydrates, proteins, Menthy acetate compound, and 1,8 Cineol, which reached 13.95 cm, 26.65 mg, 8.83 mg, 4.96, 6.80 mg g-1, 18.22%, 33.71, 31.54 µg mL-1, respectively. • Treating vegetative growths with different concentrations of PEG in interaction with colored LED lights led to significant differences, as the comparison treatment was superior in achieving the highest average for the studied traits, which included the number of vegetative branches, height, fresh and dry weight, which reached 38.15 branch/plant-1, 10.10 cm, 19.08, and 6.46 mg. As for the concentration of chlorophyll, carbohydrates, proteins, Menthy acetate, and 1,8 Cineol, the concentration of 2 mg L-1 in interaction with colored LED lights was superior in achieving the highest average of 3.75 mg g-1, 3.74 mg g-1, 13.28%, 34.72, and 33.24 micrograms ml-1. As for the enzyme peroxidase, the enzyme catalase, proline, Menthol, 2, Menthofuran, and Menthone, the concentration of 4 mg L-1 was superior. The interaction with colored LEDs resulted in the highest average response of 2.94 and 6.94 micro-absorption units g-1, 4.28 µg g-1, 40.32, 35.02 and 31.83 µg mL-1, respectively.