In vitro flowering of bitter melon

Area of Science:

• Plant Biotechnology
• Horticultural Science
• Plant Physiology

Background:

• Bitter melon (Momordica charantia L.) is a valuable crop for its medicinal and nutritional properties.
• Efficient in vitro propagation and flowering are crucial for breeding programs and genetic studies.

Purpose of the Study:

• To investigate the effects of specific nutrients and plant growth regulators on in vitro flower formation from bitter melon shoot tips.
• To understand the role of cytokinins in modulating explant development and sex determination in bitter melon.

Main Methods:

• Shoot tips of bitter melon were cultured on Murashige and Skoog medium with varying concentrations of sucrose, ferrous iron (Fe2+), and cytokinins (N6-benzyladenine and kinetin).
• Explants were assessed for flowering, chlorosis, and branch bud formation.
• In vitro pollen viability was determined using fluorescein diacetate staining and germination assays.

Main Results:

• Supplementation with 0.05 mM Fe2+ prevented chlorosis and promoted normal flowering.
• Increased carbon to nitrogen ratio favored male flower formation but inhibited vegetative growth.
• Kinetin promoted female flower formation, while N6-benzyladenine (at 1-2 µM) promoted male flower formation and branch buds, but inhibited flowering at higher concentrations (4-8 µM).
• In vitro pollen exhibited high viability.

Conclusions:

• Optimized medium conditions, including Fe2+ and specific cytokinin types and concentrations, can induce flowering from bitter melon shoot tips in vitro.
• Cytokinins play a critical role in directing morphogenesis and influencing sex expression in bitter melon explants.
• The study demonstrates the potential for in vitro techniques to aid in bitter melon research and breeding.