Advancements in cucumber micropropagation - the role of media, growth regulators and explants

Our current work aims to select suitable protocol for successful micropropagation of different
cucumber genotypes. Therefore, more than 30 articles from the1980s until now were analyzed.
Since the 1980s, advancements in tissue culture protocols have focused on optimizing media
compositions and plant growth regulators to improve shoot proliferation, rooting, and overall
plantlet development in different cucumber genotypes. Yet, Murashige and Skoog (MS)
medium has remained as a primary choice for cucumber micropropagation, regularly
supplemented with varying concentrations of cytokinins and auxins. Early studies favored BAP
as the key cytokinin for shoot induction, while NAA and IBA were commonly used for root
development. Over the years, various explants have been used as starting material for cucumber
micropropagation, including cotyledons, hypocotyls, shoot tips, nodal segments, and leaf discs.
Shoot tips and nodal segments have been widely preferred for direct organogenesis, while
cotyledons and hypocotyls have been utilized for adventitious shoot regeneration and genetic
transformation studies. The choice of explants significantly influences regeneration efficiency
and response to plant growth regulators. Although there is significant progress, challenges such
as genotype dependency, explant sensitivity, and somaclonal variation are still present. Future
research should focus on adjusting hormonal interactions, genetic stability, and cost-effective
alternatives for large-scale application.