Synergistic of growth regulators and salicylic acid enhances shoot proliferation and acclimatization in Sugar beet (Beta vulgaris L.)

• Aysar Mohammed Salim1*, Ziyad Shihab Ahmed2, Ahmed Alsawaf 3, Angham Talal Mahmoud Al-Chalabi4 Fanar Hashum Al-Hashemi5

  Author

The establishment of a fast method to in vitro multiplication and adaptation of sugar beet (Beta vulgaris L., would allow us to multiply the crop rapidly and breed it. Several treatments of α-naphthaleneacetic acid (NAA; 0.5, 1, 1.5 mg l⁻¹), 6-benzyladenine (BA; 0.5, 1, 2 mg l⁻¹) and salicylic acid SA; (5, 10,15 mg l⁻¹) were subjected to the explants based on percent callus growth shoot length root growth and survival plantlets derived from hardened hypocotyl epicotyl and petiole segments taken from seedlings in vitro The longest shoots were obtained from hypocotyl, epicotyl, and petiole explants cultured on medium supplemented with NAA (1.5 mg L⁻¹) + BA (2.0 mg L⁻¹) + SA (15 mg L⁻¹), with mean shoot lengths of 4.8, 4.7, and 4.5 cm, respectively. Furthermore, root length was significantly increased in response to the treatment containing NAA (1.5 mg L⁻¹) + BA (1.0 mg L⁻¹) + SA (5 mg L⁻¹), indicating a pronounced stimulatory effect of this growth regulator combination on root development.  respectively, when compared to the control. The treatment NAA1.5 + BA2 mg L⁻¹ SA showed the maximum amount of both callus proliferation and regrowth of shoots (200 - 350% and 16.8-32.4% respectively). The highest number of microshoots formed (2.5–2.7 shoots per explant, +167–180%) was recorded in NAA1 + BA2 + SA10 mg L⁻¹. The best acclimatization was reported for the treatment NAA 1.5 + BA2 + SA 15 mg L⁻¹ with an acclimatization rate of 68–75% compared to the control, representing an increase of 24–68%. The results in the present study confirm that NAA-BA-SA combinations can aid in improving regeneration, rooting, and acclimatization, while providing an effective pathway to further develop methods for the large-scale propagation of sugar beet for biotechnological purposes.

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