Improved flax regeneration from hypocotyls using thidiazuron as a cytokinin source

Area of Science:

• Plant Biotechnology
• Agricultural Science
• Molecular Biology

Background:

• Plant regeneration is crucial for crop improvement and genetic modification.
• Cytokinins are key plant hormones regulating cell division and organogenesis.
• Flax (Linum usitatissimum) exhibits varied responses to regeneration protocols.

Purpose of the Study:

• To evaluate the efficacy of three cytokinins (thidiazuron, benzyladenine, zeatin) on flax bud regeneration.
• To determine the optimal cytokinin and auxin combinations for organogenesis.
• To compare regeneration efficiency across different flax explant types and varieties.

Main Methods:

• Explants (hypocotyls, cotyledons, apices) from flax varieties (Ariane, Viking, Antarès) were cultured.
• Cytokinins (thidiazuron, benzyladenine, zeatin) were tested alone and with auxins (naphthalene acetic acid, indole acetic acid, 2,4-dichlorophenoxyacetic acid).
• Regeneration response and shoot initiation timing were recorded.

Main Results:

• Hypocotyl explants showed the highest responsiveness to regeneration.
• Thidiazuron was the most effective cytokinin for inducing organogenesis, followed by benzyladenine, then zeatin.
• Optimal bud regeneration occurred with 0.1-0.3 μM thidiazuron and 0.01 μM naphthalene acetic acid, with shoot initials appearing in 6 days.

Conclusions:

• Thidiazuron is a potent inducer of flax organogenesis, particularly from hypocotyl explants.
• Combining thidiazuron with naphthalene acetic acid significantly accelerates shoot regeneration in flax.
• The findings provide an optimized protocol for efficient flax regeneration, valuable for breeding programs.